elwix/files/sqlite/dist/sqlite3.h - view

File: [ELWIX - Embedded LightWeight unIX -] / elwix / files / sqlite / dist / sqlite3.h
Revision 1.4: download - view: text, annotated - select for diffs - revision graph
Mon Feb 13 16:52:50 2017 UTC (7 years, 5 months ago) by misho
Branches: MAIN
CVS tags: elwix2_6, HEAD, ELWIX2_5

ELWIX 2.5

1: /* 2: ** 2001 September 15 3: ** 4: ** The author disclaims copyright to this source code. In place of 5: ** a legal notice, here is a blessing: 6: ** 7: ** May you do good and not evil. 8: ** May you find forgiveness for yourself and forgive others. 9: ** May you share freely, never taking more than you give. 10: ** 11: ************************************************************************* 12: ** This header file defines the interface that the SQLite library 13: ** presents to client programs. If a C-function, structure, datatype, 14: ** or constant definition does not appear in this file, then it is 15: ** not a published API of SQLite, is subject to change without 16: ** notice, and should not be referenced by programs that use SQLite. 17: ** 18: ** Some of the definitions that are in this file are marked as 19: ** "experimental". Experimental interfaces are normally new 20: ** features recently added to SQLite. We do not anticipate changes 21: ** to experimental interfaces but reserve the right to make minor changes 22: ** if experience from use "in the wild" suggest such changes are prudent. 23: ** 24: ** The official C-language API documentation for SQLite is derived 25: ** from comments in this file. This file is the authoritative source 26: ** on how SQLite interfaces are supposed to operate. 27: ** 28: ** The name of this file under configuration management is "sqlite.h.in". 29: ** The makefile makes some minor changes to this file (such as inserting 30: ** the version number) and changes its name to "sqlite3.h" as 31: ** part of the build process. 32: */ 33: #ifndef SQLITE3_H 34: #define SQLITE3_H 35: #include <stdarg.h> /* Needed for the definition of va_list */ 36: 37: /* 38: ** Make sure we can call this stuff from C++. 39: */ 40: #ifdef __cplusplus 41: extern "C" { 42: #endif 43: 44: 45: /* 46: ** Provide the ability to override linkage features of the interface. 47: */ 48: #ifndef SQLITE_EXTERN 49: # define SQLITE_EXTERN extern 50: #endif 51: #ifndef SQLITE_API 52: # define SQLITE_API 53: #endif 54: #ifndef SQLITE_CDECL 55: # define SQLITE_CDECL 56: #endif 57: #ifndef SQLITE_APICALL 58: # define SQLITE_APICALL 59: #endif 60: #ifndef SQLITE_STDCALL 61: # define SQLITE_STDCALL SQLITE_APICALL 62: #endif 63: #ifndef SQLITE_CALLBACK 64: # define SQLITE_CALLBACK 65: #endif 66: #ifndef SQLITE_SYSAPI 67: # define SQLITE_SYSAPI 68: #endif 69: 70: /* 71: ** These no-op macros are used in front of interfaces to mark those 72: ** interfaces as either deprecated or experimental. New applications 73: ** should not use deprecated interfaces - they are supported for backwards 74: ** compatibility only. Application writers should be aware that 75: ** experimental interfaces are subject to change in point releases. 76: ** 77: ** These macros used to resolve to various kinds of compiler magic that 78: ** would generate warning messages when they were used. But that 79: ** compiler magic ended up generating such a flurry of bug reports 80: ** that we have taken it all out and gone back to using simple 81: ** noop macros. 82: */ 83: #define SQLITE_DEPRECATED 84: #define SQLITE_EXPERIMENTAL 85: 86: /* 87: ** Ensure these symbols were not defined by some previous header file. 88: */ 89: #ifdef SQLITE_VERSION 90: # undef SQLITE_VERSION 91: #endif 92: #ifdef SQLITE_VERSION_NUMBER 93: # undef SQLITE_VERSION_NUMBER 94: #endif 95: 96: /* 97: ** CAPI3REF: Compile-Time Library Version Numbers 98: ** 99: ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100: ** evaluates to a string literal that is the SQLite version in the 101: ** format "X.Y.Z" where X is the major version number (always 3 for 102: ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103: ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104: ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105: ** numbers used in [SQLITE_VERSION].)^ 106: ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107: ** be larger than the release from which it is derived. Either Y will 108: ** be held constant and Z will be incremented or else Y will be incremented 109: ** and Z will be reset to zero. 110: ** 111: ** Since version 3.6.18, SQLite source code has been stored in the 112: ** <a href="http://www.fossil-scm.org/">Fossil configuration management 113: ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 114: ** a string which identifies a particular check-in of SQLite 115: ** within its configuration management system. ^The SQLITE_SOURCE_ID 116: ** string contains the date and time of the check-in (UTC) and an SHA1 117: ** hash of the entire source tree. 118: ** 119: ** See also: [sqlite3_libversion()], 120: ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 121: ** [sqlite_version()] and [sqlite_source_id()]. 122: */ 123: #define SQLITE_VERSION "3.14.2" 124: #define SQLITE_VERSION_NUMBER 3014002 125: #define SQLITE_SOURCE_ID "2016-09-12 18:50:49 29dbef4b8585f753861a36d6dd102ca634197bd6" 126: 127: /* 128: ** CAPI3REF: Run-Time Library Version Numbers 129: ** KEYWORDS: sqlite3_version, sqlite3_sourceid 130: ** 131: ** These interfaces provide the same information as the [SQLITE_VERSION], 132: ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 133: ** but are associated with the library instead of the header file. ^(Cautious 134: ** programmers might include assert() statements in their application to 135: ** verify that values returned by these interfaces match the macros in 136: ** the header, and thus ensure that the application is 137: ** compiled with matching library and header files. 138: ** 139: ** <blockquote><pre> 140: ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 141: ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 142: ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 143: ** </pre></blockquote>)^ 144: ** 145: ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 146: ** macro. ^The sqlite3_libversion() function returns a pointer to the 147: ** to the sqlite3_version[] string constant. The sqlite3_libversion() 148: ** function is provided for use in DLLs since DLL users usually do not have 149: ** direct access to string constants within the DLL. ^The 150: ** sqlite3_libversion_number() function returns an integer equal to 151: ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 152: ** a pointer to a string constant whose value is the same as the 153: ** [SQLITE_SOURCE_ID] C preprocessor macro. 154: ** 155: ** See also: [sqlite_version()] and [sqlite_source_id()]. 156: */ 157: SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 158: SQLITE_API const char *sqlite3_libversion(void); 159: SQLITE_API const char *sqlite3_sourceid(void); 160: SQLITE_API int sqlite3_libversion_number(void); 161: 162: /* 163: ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 164: ** 165: ** ^The sqlite3_compileoption_used() function returns 0 or 1 166: ** indicating whether the specified option was defined at 167: ** compile time. ^The SQLITE_ prefix may be omitted from the 168: ** option name passed to sqlite3_compileoption_used(). 169: ** 170: ** ^The sqlite3_compileoption_get() function allows iterating 171: ** over the list of options that were defined at compile time by 172: ** returning the N-th compile time option string. ^If N is out of range, 173: ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 174: ** prefix is omitted from any strings returned by 175: ** sqlite3_compileoption_get(). 176: ** 177: ** ^Support for the diagnostic functions sqlite3_compileoption_used() 178: ** and sqlite3_compileoption_get() may be omitted by specifying the 179: ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 180: ** 181: ** See also: SQL functions [sqlite_compileoption_used()] and 182: ** [sqlite_compileoption_get()] and the [compile_options pragma]. 183: */ 184: #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 185: SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 186: SQLITE_API const char *sqlite3_compileoption_get(int N); 187: #endif 188: 189: /* 190: ** CAPI3REF: Test To See If The Library Is Threadsafe 191: ** 192: ** ^The sqlite3_threadsafe() function returns zero if and only if 193: ** SQLite was compiled with mutexing code omitted due to the 194: ** [SQLITE_THREADSAFE] compile-time option being set to 0. 195: ** 196: ** SQLite can be compiled with or without mutexes. When 197: ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 198: ** are enabled and SQLite is threadsafe. When the 199: ** [SQLITE_THREADSAFE] macro is 0, 200: ** the mutexes are omitted. Without the mutexes, it is not safe 201: ** to use SQLite concurrently from more than one thread. 202: ** 203: ** Enabling mutexes incurs a measurable performance penalty. 204: ** So if speed is of utmost importance, it makes sense to disable 205: ** the mutexes. But for maximum safety, mutexes should be enabled. 206: ** ^The default behavior is for mutexes to be enabled. 207: ** 208: ** This interface can be used by an application to make sure that the 209: ** version of SQLite that it is linking against was compiled with 210: ** the desired setting of the [SQLITE_THREADSAFE] macro. 211: ** 212: ** This interface only reports on the compile-time mutex setting 213: ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 214: ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 215: ** can be fully or partially disabled using a call to [sqlite3_config()] 216: ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 217: ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 218: ** sqlite3_threadsafe() function shows only the compile-time setting of 219: ** thread safety, not any run-time changes to that setting made by 220: ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 221: ** is unchanged by calls to sqlite3_config().)^ 222: ** 223: ** See the [threading mode] documentation for additional information. 224: */ 225: SQLITE_API int sqlite3_threadsafe(void); 226: 227: /* 228: ** CAPI3REF: Database Connection Handle 229: ** KEYWORDS: {database connection} {database connections} 230: ** 231: ** Each open SQLite database is represented by a pointer to an instance of 232: ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 233: ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 234: ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 235: ** and [sqlite3_close_v2()] are its destructors. There are many other 236: ** interfaces (such as 237: ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 238: ** [sqlite3_busy_timeout()] to name but three) that are methods on an 239: ** sqlite3 object. 240: */ 241: typedef struct sqlite3 sqlite3; 242: 243: /* 244: ** CAPI3REF: 64-Bit Integer Types 245: ** KEYWORDS: sqlite_int64 sqlite_uint64 246: ** 247: ** Because there is no cross-platform way to specify 64-bit integer types 248: ** SQLite includes typedefs for 64-bit signed and unsigned integers. 249: ** 250: ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 251: ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 252: ** compatibility only. 253: ** 254: ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 255: ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 256: ** sqlite3_uint64 and sqlite_uint64 types can store integer values 257: ** between 0 and +18446744073709551615 inclusive. 258: */ 259: #ifdef SQLITE_INT64_TYPE 260: typedef SQLITE_INT64_TYPE sqlite_int64; 261: typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 262: #elif defined(_MSC_VER) || defined(__BORLANDC__) 263: typedef __int64 sqlite_int64; 264: typedef unsigned __int64 sqlite_uint64; 265: #else 266: typedef long long int sqlite_int64; 267: typedef unsigned long long int sqlite_uint64; 268: #endif 269: typedef sqlite_int64 sqlite3_int64; 270: typedef sqlite_uint64 sqlite3_uint64; 271: 272: /* 273: ** If compiling for a processor that lacks floating point support, 274: ** substitute integer for floating-point. 275: */ 276: #ifdef SQLITE_OMIT_FLOATING_POINT 277: # define double sqlite3_int64 278: #endif 279: 280: /* 281: ** CAPI3REF: Closing A Database Connection 282: ** DESTRUCTOR: sqlite3 283: ** 284: ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 285: ** for the [sqlite3] object. 286: ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 287: ** the [sqlite3] object is successfully destroyed and all associated 288: ** resources are deallocated. 289: ** 290: ** ^If the database connection is associated with unfinalized prepared 291: ** statements or unfinished sqlite3_backup objects then sqlite3_close() 292: ** will leave the database connection open and return [SQLITE_BUSY]. 293: ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 294: ** and/or unfinished sqlite3_backups, then the database connection becomes 295: ** an unusable "zombie" which will automatically be deallocated when the 296: ** last prepared statement is finalized or the last sqlite3_backup is 297: ** finished. The sqlite3_close_v2() interface is intended for use with 298: ** host languages that are garbage collected, and where the order in which 299: ** destructors are called is arbitrary. 300: ** 301: ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 302: ** [sqlite3_blob_close | close] all [BLOB handles], and 303: ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 304: ** with the [sqlite3] object prior to attempting to close the object. ^If 305: ** sqlite3_close_v2() is called on a [database connection] that still has 306: ** outstanding [prepared statements], [BLOB handles], and/or 307: ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 308: ** of resources is deferred until all [prepared statements], [BLOB handles], 309: ** and [sqlite3_backup] objects are also destroyed. 310: ** 311: ** ^If an [sqlite3] object is destroyed while a transaction is open, 312: ** the transaction is automatically rolled back. 313: ** 314: ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 315: ** must be either a NULL 316: ** pointer or an [sqlite3] object pointer obtained 317: ** from [sqlite3_open()], [sqlite3_open16()], or 318: ** [sqlite3_open_v2()], and not previously closed. 319: ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 320: ** argument is a harmless no-op. 321: */ 322: SQLITE_API int sqlite3_close(sqlite3*); 323: SQLITE_API int sqlite3_close_v2(sqlite3*); 324: 325: /* 326: ** The type for a callback function. 327: ** This is legacy and deprecated. It is included for historical 328: ** compatibility and is not documented. 329: */ 330: typedef int (*sqlite3_callback)(void*,int,char**, char**); 331: 332: /* 333: ** CAPI3REF: One-Step Query Execution Interface 334: ** METHOD: sqlite3 335: ** 336: ** The sqlite3_exec() interface is a convenience wrapper around 337: ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 338: ** that allows an application to run multiple statements of SQL 339: ** without having to use a lot of C code. 340: ** 341: ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 342: ** semicolon-separate SQL statements passed into its 2nd argument, 343: ** in the context of the [database connection] passed in as its 1st 344: ** argument. ^If the callback function of the 3rd argument to 345: ** sqlite3_exec() is not NULL, then it is invoked for each result row 346: ** coming out of the evaluated SQL statements. ^The 4th argument to 347: ** sqlite3_exec() is relayed through to the 1st argument of each 348: ** callback invocation. ^If the callback pointer to sqlite3_exec() 349: ** is NULL, then no callback is ever invoked and result rows are 350: ** ignored. 351: ** 352: ** ^If an error occurs while evaluating the SQL statements passed into 353: ** sqlite3_exec(), then execution of the current statement stops and 354: ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 355: ** is not NULL then any error message is written into memory obtained 356: ** from [sqlite3_malloc()] and passed back through the 5th parameter. 357: ** To avoid memory leaks, the application should invoke [sqlite3_free()] 358: ** on error message strings returned through the 5th parameter of 359: ** sqlite3_exec() after the error message string is no longer needed. 360: ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 361: ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 362: ** NULL before returning. 363: ** 364: ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 365: ** routine returns SQLITE_ABORT without invoking the callback again and 366: ** without running any subsequent SQL statements. 367: ** 368: ** ^The 2nd argument to the sqlite3_exec() callback function is the 369: ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 370: ** callback is an array of pointers to strings obtained as if from 371: ** [sqlite3_column_text()], one for each column. ^If an element of a 372: ** result row is NULL then the corresponding string pointer for the 373: ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 374: ** sqlite3_exec() callback is an array of pointers to strings where each 375: ** entry represents the name of corresponding result column as obtained 376: ** from [sqlite3_column_name()]. 377: ** 378: ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 379: ** to an empty string, or a pointer that contains only whitespace and/or 380: ** SQL comments, then no SQL statements are evaluated and the database 381: ** is not changed. 382: ** 383: ** Restrictions: 384: ** 385: ** <ul> 386: ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 387: ** is a valid and open [database connection]. 388: ** <li> The application must not close the [database connection] specified by 389: ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 390: ** <li> The application must not modify the SQL statement text passed into 391: ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 392: ** </ul> 393: */ 394: SQLITE_API int sqlite3_exec( 395: sqlite3*, /* An open database */ 396: const char *sql, /* SQL to be evaluated */ 397: int (*callback)(void*,int,char**,char**), /* Callback function */ 398: void *, /* 1st argument to callback */ 399: char **errmsg /* Error msg written here */ 400: ); 401: 402: /* 403: ** CAPI3REF: Result Codes 404: ** KEYWORDS: {result code definitions} 405: ** 406: ** Many SQLite functions return an integer result code from the set shown 407: ** here in order to indicate success or failure. 408: ** 409: ** New error codes may be added in future versions of SQLite. 410: ** 411: ** See also: [extended result code definitions] 412: */ 413: #define SQLITE_OK 0 /* Successful result */ 414: /* beginning-of-error-codes */ 415: #define SQLITE_ERROR 1 /* SQL error or missing database */ 416: #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 417: #define SQLITE_PERM 3 /* Access permission denied */ 418: #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 419: #define SQLITE_BUSY 5 /* The database file is locked */ 420: #define SQLITE_LOCKED 6 /* A table in the database is locked */ 421: #define SQLITE_NOMEM 7 /* A malloc() failed */ 422: #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 423: #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 424: #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 425: #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 426: #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 427: #define SQLITE_FULL 13 /* Insertion failed because database is full */ 428: #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 429: #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 430: #define SQLITE_EMPTY 16 /* Database is empty */ 431: #define SQLITE_SCHEMA 17 /* The database schema changed */ 432: #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 433: #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 434: #define SQLITE_MISMATCH 20 /* Data type mismatch */ 435: #define SQLITE_MISUSE 21 /* Library used incorrectly */ 436: #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 437: #define SQLITE_AUTH 23 /* Authorization denied */ 438: #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 439: #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 440: #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 441: #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 442: #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 443: #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 444: #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 445: /* end-of-error-codes */ 446: 447: /* 448: ** CAPI3REF: Extended Result Codes 449: ** KEYWORDS: {extended result code definitions} 450: ** 451: ** In its default configuration, SQLite API routines return one of 30 integer 452: ** [result codes]. However, experience has shown that many of 453: ** these result codes are too coarse-grained. They do not provide as 454: ** much information about problems as programmers might like. In an effort to 455: ** address this, newer versions of SQLite (version 3.3.8 and later) include 456: ** support for additional result codes that provide more detailed information 457: ** about errors. These [extended result codes] are enabled or disabled 458: ** on a per database connection basis using the 459: ** [sqlite3_extended_result_codes()] API. Or, the extended code for 460: ** the most recent error can be obtained using 461: ** [sqlite3_extended_errcode()]. 462: */ 463: #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 464: #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 465: #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 466: #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 467: #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 468: #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 469: #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 470: #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 471: #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 472: #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 473: #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 474: #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 475: #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 476: #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 477: #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 478: #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 479: #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 480: #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 481: #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 482: #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 483: #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 484: #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 485: #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 486: #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 487: #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 488: #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 489: #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 490: #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 491: #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 492: #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 493: #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 494: #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 495: #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 496: #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 497: #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 498: #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 499: #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 500: #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 501: #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 502: #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 503: #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 504: #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 505: #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 506: #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 507: #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 508: #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 509: #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 510: #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 511: #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 512: #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 513: #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 514: #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 515: #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 516: #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 517: #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 518: #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 519: 520: /* 521: ** CAPI3REF: Flags For File Open Operations 522: ** 523: ** These bit values are intended for use in the 524: ** 3rd parameter to the [sqlite3_open_v2()] interface and 525: ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 526: */ 527: #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 528: #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 529: #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 530: #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 531: #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 532: #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 533: #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 534: #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 535: #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 536: #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 537: #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 538: #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 539: #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 540: #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 541: #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 542: #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 543: #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 544: #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 545: #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 546: #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 547: 548: /* Reserved: 0x00F00000 */ 549: 550: /* 551: ** CAPI3REF: Device Characteristics 552: ** 553: ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 554: ** object returns an integer which is a vector of these 555: ** bit values expressing I/O characteristics of the mass storage 556: ** device that holds the file that the [sqlite3_io_methods] 557: ** refers to. 558: ** 559: ** The SQLITE_IOCAP_ATOMIC property means that all writes of 560: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 561: ** mean that writes of blocks that are nnn bytes in size and 562: ** are aligned to an address which is an integer multiple of 563: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 564: ** that when data is appended to a file, the data is appended 565: ** first then the size of the file is extended, never the other 566: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 567: ** information is written to disk in the same order as calls 568: ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 569: ** after reboot following a crash or power loss, the only bytes in a 570: ** file that were written at the application level might have changed 571: ** and that adjacent bytes, even bytes within the same sector are 572: ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 573: ** flag indicate that a file cannot be deleted when open. The 574: ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 575: ** read-only media and cannot be changed even by processes with 576: ** elevated privileges. 577: */ 578: #define SQLITE_IOCAP_ATOMIC 0x00000001 579: #define SQLITE_IOCAP_ATOMIC512 0x00000002 580: #define SQLITE_IOCAP_ATOMIC1K 0x00000004 581: #define SQLITE_IOCAP_ATOMIC2K 0x00000008 582: #define SQLITE_IOCAP_ATOMIC4K 0x00000010 583: #define SQLITE_IOCAP_ATOMIC8K 0x00000020 584: #define SQLITE_IOCAP_ATOMIC16K 0x00000040 585: #define SQLITE_IOCAP_ATOMIC32K 0x00000080 586: #define SQLITE_IOCAP_ATOMIC64K 0x00000100 587: #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 588: #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 589: #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 590: #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 591: #define SQLITE_IOCAP_IMMUTABLE 0x00002000 592: 593: /* 594: ** CAPI3REF: File Locking Levels 595: ** 596: ** SQLite uses one of these integer values as the second 597: ** argument to calls it makes to the xLock() and xUnlock() methods 598: ** of an [sqlite3_io_methods] object. 599: */ 600: #define SQLITE_LOCK_NONE 0 601: #define SQLITE_LOCK_SHARED 1 602: #define SQLITE_LOCK_RESERVED 2 603: #define SQLITE_LOCK_PENDING 3 604: #define SQLITE_LOCK_EXCLUSIVE 4 605: 606: /* 607: ** CAPI3REF: Synchronization Type Flags 608: ** 609: ** When SQLite invokes the xSync() method of an 610: ** [sqlite3_io_methods] object it uses a combination of 611: ** these integer values as the second argument. 612: ** 613: ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 614: ** sync operation only needs to flush data to mass storage. Inode 615: ** information need not be flushed. If the lower four bits of the flag 616: ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 617: ** If the lower four bits equal SQLITE_SYNC_FULL, that means 618: ** to use Mac OS X style fullsync instead of fsync(). 619: ** 620: ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 621: ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 622: ** settings. The [synchronous pragma] determines when calls to the 623: ** xSync VFS method occur and applies uniformly across all platforms. 624: ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 625: ** energetic or rigorous or forceful the sync operations are and 626: ** only make a difference on Mac OSX for the default SQLite code. 627: ** (Third-party VFS implementations might also make the distinction 628: ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 629: ** operating systems natively supported by SQLite, only Mac OSX 630: ** cares about the difference.) 631: */ 632: #define SQLITE_SYNC_NORMAL 0x00002 633: #define SQLITE_SYNC_FULL 0x00003 634: #define SQLITE_SYNC_DATAONLY 0x00010 635: 636: /* 637: ** CAPI3REF: OS Interface Open File Handle 638: ** 639: ** An [sqlite3_file] object represents an open file in the 640: ** [sqlite3_vfs | OS interface layer]. Individual OS interface 641: ** implementations will 642: ** want to subclass this object by appending additional fields 643: ** for their own use. The pMethods entry is a pointer to an 644: ** [sqlite3_io_methods] object that defines methods for performing 645: ** I/O operations on the open file. 646: */ 647: typedef struct sqlite3_file sqlite3_file; 648: struct sqlite3_file { 649: const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 650: }; 651: 652: /* 653: ** CAPI3REF: OS Interface File Virtual Methods Object 654: ** 655: ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 656: ** [sqlite3_file] object (or, more commonly, a subclass of the 657: ** [sqlite3_file] object) with a pointer to an instance of this object. 658: ** This object defines the methods used to perform various operations 659: ** against the open file represented by the [sqlite3_file] object. 660: ** 661: ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 662: ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 663: ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 664: ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 665: ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 666: ** to NULL. 667: ** 668: ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 669: ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 670: ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 671: ** flag may be ORed in to indicate that only the data of the file 672: ** and not its inode needs to be synced. 673: ** 674: ** The integer values to xLock() and xUnlock() are one of 675: ** <ul> 676: ** <li> [SQLITE_LOCK_NONE], 677: ** <li> [SQLITE_LOCK_SHARED], 678: ** <li> [SQLITE_LOCK_RESERVED], 679: ** <li> [SQLITE_LOCK_PENDING], or 680: ** <li> [SQLITE_LOCK_EXCLUSIVE]. 681: ** </ul> 682: ** xLock() increases the lock. xUnlock() decreases the lock. 683: ** The xCheckReservedLock() method checks whether any database connection, 684: ** either in this process or in some other process, is holding a RESERVED, 685: ** PENDING, or EXCLUSIVE lock on the file. It returns true 686: ** if such a lock exists and false otherwise. 687: ** 688: ** The xFileControl() method is a generic interface that allows custom 689: ** VFS implementations to directly control an open file using the 690: ** [sqlite3_file_control()] interface. The second "op" argument is an 691: ** integer opcode. The third argument is a generic pointer intended to 692: ** point to a structure that may contain arguments or space in which to 693: ** write return values. Potential uses for xFileControl() might be 694: ** functions to enable blocking locks with timeouts, to change the 695: ** locking strategy (for example to use dot-file locks), to inquire 696: ** about the status of a lock, or to break stale locks. The SQLite 697: ** core reserves all opcodes less than 100 for its own use. 698: ** A [file control opcodes | list of opcodes] less than 100 is available. 699: ** Applications that define a custom xFileControl method should use opcodes 700: ** greater than 100 to avoid conflicts. VFS implementations should 701: ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 702: ** recognize. 703: ** 704: ** The xSectorSize() method returns the sector size of the 705: ** device that underlies the file. The sector size is the 706: ** minimum write that can be performed without disturbing 707: ** other bytes in the file. The xDeviceCharacteristics() 708: ** method returns a bit vector describing behaviors of the 709: ** underlying device: 710: ** 711: ** <ul> 712: ** <li> [SQLITE_IOCAP_ATOMIC] 713: ** <li> [SQLITE_IOCAP_ATOMIC512] 714: ** <li> [SQLITE_IOCAP_ATOMIC1K] 715: ** <li> [SQLITE_IOCAP_ATOMIC2K] 716: ** <li> [SQLITE_IOCAP_ATOMIC4K] 717: ** <li> [SQLITE_IOCAP_ATOMIC8K] 718: ** <li> [SQLITE_IOCAP_ATOMIC16K] 719: ** <li> [SQLITE_IOCAP_ATOMIC32K] 720: ** <li> [SQLITE_IOCAP_ATOMIC64K] 721: ** <li> [SQLITE_IOCAP_SAFE_APPEND] 722: ** <li> [SQLITE_IOCAP_SEQUENTIAL] 723: ** </ul> 724: ** 725: ** The SQLITE_IOCAP_ATOMIC property means that all writes of 726: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 727: ** mean that writes of blocks that are nnn bytes in size and 728: ** are aligned to an address which is an integer multiple of 729: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 730: ** that when data is appended to a file, the data is appended 731: ** first then the size of the file is extended, never the other 732: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 733: ** information is written to disk in the same order as calls 734: ** to xWrite(). 735: ** 736: ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 737: ** in the unread portions of the buffer with zeros. A VFS that 738: ** fails to zero-fill short reads might seem to work. However, 739: ** failure to zero-fill short reads will eventually lead to 740: ** database corruption. 741: */ 742: typedef struct sqlite3_io_methods sqlite3_io_methods; 743: struct sqlite3_io_methods { 744: int iVersion; 745: int (*xClose)(sqlite3_file*); 746: int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 747: int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 748: int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 749: int (*xSync)(sqlite3_file*, int flags); 750: int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 751: int (*xLock)(sqlite3_file*, int); 752: int (*xUnlock)(sqlite3_file*, int); 753: int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 754: int (*xFileControl)(sqlite3_file*, int op, void *pArg); 755: int (*xSectorSize)(sqlite3_file*); 756: int (*xDeviceCharacteristics)(sqlite3_file*); 757: /* Methods above are valid for version 1 */ 758: int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 759: int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 760: void (*xShmBarrier)(sqlite3_file*); 761: int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 762: /* Methods above are valid for version 2 */ 763: int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 764: int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 765: /* Methods above are valid for version 3 */ 766: /* Additional methods may be added in future releases */ 767: }; 768: 769: /* 770: ** CAPI3REF: Standard File Control Opcodes 771: ** KEYWORDS: {file control opcodes} {file control opcode} 772: ** 773: ** These integer constants are opcodes for the xFileControl method 774: ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 775: ** interface. 776: ** 777: ** <ul> 778: ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 779: ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 780: ** opcode causes the xFileControl method to write the current state of 781: ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 782: ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 783: ** into an integer that the pArg argument points to. This capability 784: ** is used during testing and is only available when the SQLITE_TEST 785: ** compile-time option is used. 786: ** 787: ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 788: ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 789: ** layer a hint of how large the database file will grow to be during the 790: ** current transaction. This hint is not guaranteed to be accurate but it 791: ** is often close. The underlying VFS might choose to preallocate database 792: ** file space based on this hint in order to help writes to the database 793: ** file run faster. 794: ** 795: ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 796: ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 797: ** extends and truncates the database file in chunks of a size specified 798: ** by the user. The fourth argument to [sqlite3_file_control()] should 799: ** point to an integer (type int) containing the new chunk-size to use 800: ** for the nominated database. Allocating database file space in large 801: ** chunks (say 1MB at a time), may reduce file-system fragmentation and 802: ** improve performance on some systems. 803: ** 804: ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 805: ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 806: ** to the [sqlite3_file] object associated with a particular database 807: ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 808: ** 809: ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 810: ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 811: ** to the [sqlite3_file] object associated with the journal file (either 812: ** the [rollback journal] or the [write-ahead log]) for a particular database 813: ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 814: ** 815: ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 816: ** No longer in use. 817: ** 818: ** <li>[[SQLITE_FCNTL_SYNC]] 819: ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 820: ** sent to the VFS immediately before the xSync method is invoked on a 821: ** database file descriptor. Or, if the xSync method is not invoked 822: ** because the user has configured SQLite with 823: ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 824: ** of the xSync method. In most cases, the pointer argument passed with 825: ** this file-control is NULL. However, if the database file is being synced 826: ** as part of a multi-database commit, the argument points to a nul-terminated 827: ** string containing the transactions master-journal file name. VFSes that 828: ** do not need this signal should silently ignore this opcode. Applications 829: ** should not call [sqlite3_file_control()] with this opcode as doing so may 830: ** disrupt the operation of the specialized VFSes that do require it. 831: ** 832: ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 833: ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 834: ** and sent to the VFS after a transaction has been committed immediately 835: ** but before the database is unlocked. VFSes that do not need this signal 836: ** should silently ignore this opcode. Applications should not call 837: ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 838: ** operation of the specialized VFSes that do require it. 839: ** 840: ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 841: ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 842: ** retry counts and intervals for certain disk I/O operations for the 843: ** windows [VFS] in order to provide robustness in the presence of 844: ** anti-virus programs. By default, the windows VFS will retry file read, 845: ** file write, and file delete operations up to 10 times, with a delay 846: ** of 25 milliseconds before the first retry and with the delay increasing 847: ** by an additional 25 milliseconds with each subsequent retry. This 848: ** opcode allows these two values (10 retries and 25 milliseconds of delay) 849: ** to be adjusted. The values are changed for all database connections 850: ** within the same process. The argument is a pointer to an array of two 851: ** integers where the first integer i the new retry count and the second 852: ** integer is the delay. If either integer is negative, then the setting 853: ** is not changed but instead the prior value of that setting is written 854: ** into the array entry, allowing the current retry settings to be 855: ** interrogated. The zDbName parameter is ignored. 856: ** 857: ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 858: ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 859: ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 860: ** write ahead log and shared memory files used for transaction control 861: ** are automatically deleted when the latest connection to the database 862: ** closes. Setting persistent WAL mode causes those files to persist after 863: ** close. Persisting the files is useful when other processes that do not 864: ** have write permission on the directory containing the database file want 865: ** to read the database file, as the WAL and shared memory files must exist 866: ** in order for the database to be readable. The fourth parameter to 867: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 868: ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 869: ** WAL mode. If the integer is -1, then it is overwritten with the current 870: ** WAL persistence setting. 871: ** 872: ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 873: ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 874: ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 875: ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 876: ** xDeviceCharacteristics methods. The fourth parameter to 877: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 878: ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 879: ** mode. If the integer is -1, then it is overwritten with the current 880: ** zero-damage mode setting. 881: ** 882: ** <li>[[SQLITE_FCNTL_OVERWRITE]] 883: ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 884: ** a write transaction to indicate that, unless it is rolled back for some 885: ** reason, the entire database file will be overwritten by the current 886: ** transaction. This is used by VACUUM operations. 887: ** 888: ** <li>[[SQLITE_FCNTL_VFSNAME]] 889: ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 890: ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 891: ** final bottom-level VFS are written into memory obtained from 892: ** [sqlite3_malloc()] and the result is stored in the char* variable 893: ** that the fourth parameter of [sqlite3_file_control()] points to. 894: ** The caller is responsible for freeing the memory when done. As with 895: ** all file-control actions, there is no guarantee that this will actually 896: ** do anything. Callers should initialize the char* variable to a NULL 897: ** pointer in case this file-control is not implemented. This file-control 898: ** is intended for diagnostic use only. 899: ** 900: ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 901: ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 902: ** [VFSes] currently in use. ^(The argument X in 903: ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 904: ** of type "[sqlite3_vfs] **". This opcodes will set *X 905: ** to a pointer to the top-level VFS.)^ 906: ** ^When there are multiple VFS shims in the stack, this opcode finds the 907: ** upper-most shim only. 908: ** 909: ** <li>[[SQLITE_FCNTL_PRAGMA]] 910: ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 911: ** file control is sent to the open [sqlite3_file] object corresponding 912: ** to the database file to which the pragma statement refers. ^The argument 913: ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 914: ** pointers to strings (char**) in which the second element of the array 915: ** is the name of the pragma and the third element is the argument to the 916: ** pragma or NULL if the pragma has no argument. ^The handler for an 917: ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 918: ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 919: ** or the equivalent and that string will become the result of the pragma or 920: ** the error message if the pragma fails. ^If the 921: ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 922: ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 923: ** file control returns [SQLITE_OK], then the parser assumes that the 924: ** VFS has handled the PRAGMA itself and the parser generates a no-op 925: ** prepared statement if result string is NULL, or that returns a copy 926: ** of the result string if the string is non-NULL. 927: ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 928: ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 929: ** that the VFS encountered an error while handling the [PRAGMA] and the 930: ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 931: ** file control occurs at the beginning of pragma statement analysis and so 932: ** it is able to override built-in [PRAGMA] statements. 933: ** 934: ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 935: ** ^The [SQLITE_FCNTL_BUSYHANDLER] 936: ** file-control may be invoked by SQLite on the database file handle 937: ** shortly after it is opened in order to provide a custom VFS with access 938: ** to the connections busy-handler callback. The argument is of type (void **) 939: ** - an array of two (void *) values. The first (void *) actually points 940: ** to a function of type (int (*)(void *)). In order to invoke the connections 941: ** busy-handler, this function should be invoked with the second (void *) in 942: ** the array as the only argument. If it returns non-zero, then the operation 943: ** should be retried. If it returns zero, the custom VFS should abandon the 944: ** current operation. 945: ** 946: ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 947: ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 948: ** to have SQLite generate a 949: ** temporary filename using the same algorithm that is followed to generate 950: ** temporary filenames for TEMP tables and other internal uses. The 951: ** argument should be a char** which will be filled with the filename 952: ** written into memory obtained from [sqlite3_malloc()]. The caller should 953: ** invoke [sqlite3_free()] on the result to avoid a memory leak. 954: ** 955: ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 956: ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 957: ** maximum number of bytes that will be used for memory-mapped I/O. 958: ** The argument is a pointer to a value of type sqlite3_int64 that 959: ** is an advisory maximum number of bytes in the file to memory map. The 960: ** pointer is overwritten with the old value. The limit is not changed if 961: ** the value originally pointed to is negative, and so the current limit 962: ** can be queried by passing in a pointer to a negative number. This 963: ** file-control is used internally to implement [PRAGMA mmap_size]. 964: ** 965: ** <li>[[SQLITE_FCNTL_TRACE]] 966: ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 967: ** to the VFS about what the higher layers of the SQLite stack are doing. 968: ** This file control is used by some VFS activity tracing [shims]. 969: ** The argument is a zero-terminated string. Higher layers in the 970: ** SQLite stack may generate instances of this file control if 971: ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 972: ** 973: ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 974: ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 975: ** pointer to an integer and it writes a boolean into that integer depending 976: ** on whether or not the file has been renamed, moved, or deleted since it 977: ** was first opened. 978: ** 979: ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 980: ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 981: ** opcode causes the xFileControl method to swap the file handle with the one 982: ** pointed to by the pArg argument. This capability is used during testing 983: ** and only needs to be supported when SQLITE_TEST is defined. 984: ** 985: ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 986: ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 987: ** be advantageous to block on the next WAL lock if the lock is not immediately 988: ** available. The WAL subsystem issues this signal during rare 989: ** circumstances in order to fix a problem with priority inversion. 990: ** Applications should <em>not</em> use this file-control. 991: ** 992: ** <li>[[SQLITE_FCNTL_ZIPVFS]] 993: ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 994: ** VFS should return SQLITE_NOTFOUND for this opcode. 995: ** 996: ** <li>[[SQLITE_FCNTL_RBU]] 997: ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 998: ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 999: ** this opcode. 1000: ** </ul> 1001: */ 1002: #define SQLITE_FCNTL_LOCKSTATE 1 1003: #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1004: #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1005: #define SQLITE_FCNTL_LAST_ERRNO 4 1006: #define SQLITE_FCNTL_SIZE_HINT 5 1007: #define SQLITE_FCNTL_CHUNK_SIZE 6 1008: #define SQLITE_FCNTL_FILE_POINTER 7 1009: #define SQLITE_FCNTL_SYNC_OMITTED 8 1010: #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1011: #define SQLITE_FCNTL_PERSIST_WAL 10 1012: #define SQLITE_FCNTL_OVERWRITE 11 1013: #define SQLITE_FCNTL_VFSNAME 12 1014: #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1015: #define SQLITE_FCNTL_PRAGMA 14 1016: #define SQLITE_FCNTL_BUSYHANDLER 15 1017: #define SQLITE_FCNTL_TEMPFILENAME 16 1018: #define SQLITE_FCNTL_MMAP_SIZE 18 1019: #define SQLITE_FCNTL_TRACE 19 1020: #define SQLITE_FCNTL_HAS_MOVED 20 1021: #define SQLITE_FCNTL_SYNC 21 1022: #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1023: #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1024: #define SQLITE_FCNTL_WAL_BLOCK 24 1025: #define SQLITE_FCNTL_ZIPVFS 25 1026: #define SQLITE_FCNTL_RBU 26 1027: #define SQLITE_FCNTL_VFS_POINTER 27 1028: #define SQLITE_FCNTL_JOURNAL_POINTER 28 1029: 1030: /* deprecated names */ 1031: #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1032: #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1033: #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1034: 1035: 1036: /* 1037: ** CAPI3REF: Mutex Handle 1038: ** 1039: ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1040: ** abstract type for a mutex object. The SQLite core never looks 1041: ** at the internal representation of an [sqlite3_mutex]. It only 1042: ** deals with pointers to the [sqlite3_mutex] object. 1043: ** 1044: ** Mutexes are created using [sqlite3_mutex_alloc()]. 1045: */ 1046: typedef struct sqlite3_mutex sqlite3_mutex; 1047: 1048: /* 1049: ** CAPI3REF: Loadable Extension Thunk 1050: ** 1051: ** A pointer to the opaque sqlite3_api_routines structure is passed as 1052: ** the third parameter to entry points of [loadable extensions]. This 1053: ** structure must be typedefed in order to work around compiler warnings 1054: ** on some platforms. 1055: */ 1056: typedef struct sqlite3_api_routines sqlite3_api_routines; 1057: 1058: /* 1059: ** CAPI3REF: OS Interface Object 1060: ** 1061: ** An instance of the sqlite3_vfs object defines the interface between 1062: ** the SQLite core and the underlying operating system. The "vfs" 1063: ** in the name of the object stands for "virtual file system". See 1064: ** the [VFS | VFS documentation] for further information. 1065: ** 1066: ** The value of the iVersion field is initially 1 but may be larger in 1067: ** future versions of SQLite. Additional fields may be appended to this 1068: ** object when the iVersion value is increased. Note that the structure 1069: ** of the sqlite3_vfs object changes in the transaction between 1070: ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1071: ** modified. 1072: ** 1073: ** The szOsFile field is the size of the subclassed [sqlite3_file] 1074: ** structure used by this VFS. mxPathname is the maximum length of 1075: ** a pathname in this VFS. 1076: ** 1077: ** Registered sqlite3_vfs objects are kept on a linked list formed by 1078: ** the pNext pointer. The [sqlite3_vfs_register()] 1079: ** and [sqlite3_vfs_unregister()] interfaces manage this list 1080: ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1081: ** searches the list. Neither the application code nor the VFS 1082: ** implementation should use the pNext pointer. 1083: ** 1084: ** The pNext field is the only field in the sqlite3_vfs 1085: ** structure that SQLite will ever modify. SQLite will only access 1086: ** or modify this field while holding a particular static mutex. 1087: ** The application should never modify anything within the sqlite3_vfs 1088: ** object once the object has been registered. 1089: ** 1090: ** The zName field holds the name of the VFS module. The name must 1091: ** be unique across all VFS modules. 1092: ** 1093: ** [[sqlite3_vfs.xOpen]] 1094: ** ^SQLite guarantees that the zFilename parameter to xOpen 1095: ** is either a NULL pointer or string obtained 1096: ** from xFullPathname() with an optional suffix added. 1097: ** ^If a suffix is added to the zFilename parameter, it will 1098: ** consist of a single "-" character followed by no more than 1099: ** 11 alphanumeric and/or "-" characters. 1100: ** ^SQLite further guarantees that 1101: ** the string will be valid and unchanged until xClose() is 1102: ** called. Because of the previous sentence, 1103: ** the [sqlite3_file] can safely store a pointer to the 1104: ** filename if it needs to remember the filename for some reason. 1105: ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1106: ** must invent its own temporary name for the file. ^Whenever the 1107: ** xFilename parameter is NULL it will also be the case that the 1108: ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1109: ** 1110: ** The flags argument to xOpen() includes all bits set in 1111: ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1112: ** or [sqlite3_open16()] is used, then flags includes at least 1113: ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1114: ** If xOpen() opens a file read-only then it sets *pOutFlags to 1115: ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1116: ** 1117: ** ^(SQLite will also add one of the following flags to the xOpen() 1118: ** call, depending on the object being opened: 1119: ** 1120: ** <ul> 1121: ** <li> [SQLITE_OPEN_MAIN_DB] 1122: ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1123: ** <li> [SQLITE_OPEN_TEMP_DB] 1124: ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1125: ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1126: ** <li> [SQLITE_OPEN_SUBJOURNAL] 1127: ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1128: ** <li> [SQLITE_OPEN_WAL] 1129: ** </ul>)^ 1130: ** 1131: ** The file I/O implementation can use the object type flags to 1132: ** change the way it deals with files. For example, an application 1133: ** that does not care about crash recovery or rollback might make 1134: ** the open of a journal file a no-op. Writes to this journal would 1135: ** also be no-ops, and any attempt to read the journal would return 1136: ** SQLITE_IOERR. Or the implementation might recognize that a database 1137: ** file will be doing page-aligned sector reads and writes in a random 1138: ** order and set up its I/O subsystem accordingly. 1139: ** 1140: ** SQLite might also add one of the following flags to the xOpen method: 1141: ** 1142: ** <ul> 1143: ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1144: ** <li> [SQLITE_OPEN_EXCLUSIVE] 1145: ** </ul> 1146: ** 1147: ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1148: ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1149: ** will be set for TEMP databases and their journals, transient 1150: ** databases, and subjournals. 1151: ** 1152: ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1153: ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1154: ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1155: ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1156: ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1157: ** be created, and that it is an error if it already exists. 1158: ** It is <i>not</i> used to indicate the file should be opened 1159: ** for exclusive access. 1160: ** 1161: ** ^At least szOsFile bytes of memory are allocated by SQLite 1162: ** to hold the [sqlite3_file] structure passed as the third 1163: ** argument to xOpen. The xOpen method does not have to 1164: ** allocate the structure; it should just fill it in. Note that 1165: ** the xOpen method must set the sqlite3_file.pMethods to either 1166: ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1167: ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1168: ** element will be valid after xOpen returns regardless of the success 1169: ** or failure of the xOpen call. 1170: ** 1171: ** [[sqlite3_vfs.xAccess]] 1172: ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1173: ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1174: ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1175: ** to test whether a file is at least readable. The file can be a 1176: ** directory. 1177: ** 1178: ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1179: ** output buffer xFullPathname. The exact size of the output buffer 1180: ** is also passed as a parameter to both methods. If the output buffer 1181: ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1182: ** handled as a fatal error by SQLite, vfs implementations should endeavor 1183: ** to prevent this by setting mxPathname to a sufficiently large value. 1184: ** 1185: ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1186: ** interfaces are not strictly a part of the filesystem, but they are 1187: ** included in the VFS structure for completeness. 1188: ** The xRandomness() function attempts to return nBytes bytes 1189: ** of good-quality randomness into zOut. The return value is 1190: ** the actual number of bytes of randomness obtained. 1191: ** The xSleep() method causes the calling thread to sleep for at 1192: ** least the number of microseconds given. ^The xCurrentTime() 1193: ** method returns a Julian Day Number for the current date and time as 1194: ** a floating point value. 1195: ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1196: ** Day Number multiplied by 86400000 (the number of milliseconds in 1197: ** a 24-hour day). 1198: ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1199: ** date and time if that method is available (if iVersion is 2 or 1200: ** greater and the function pointer is not NULL) and will fall back 1201: ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1202: ** 1203: ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1204: ** are not used by the SQLite core. These optional interfaces are provided 1205: ** by some VFSes to facilitate testing of the VFS code. By overriding 1206: ** system calls with functions under its control, a test program can 1207: ** simulate faults and error conditions that would otherwise be difficult 1208: ** or impossible to induce. The set of system calls that can be overridden 1209: ** varies from one VFS to another, and from one version of the same VFS to the 1210: ** next. Applications that use these interfaces must be prepared for any 1211: ** or all of these interfaces to be NULL or for their behavior to change 1212: ** from one release to the next. Applications must not attempt to access 1213: ** any of these methods if the iVersion of the VFS is less than 3. 1214: */ 1215: typedef struct sqlite3_vfs sqlite3_vfs; 1216: typedef void (*sqlite3_syscall_ptr)(void); 1217: struct sqlite3_vfs { 1218: int iVersion; /* Structure version number (currently 3) */ 1219: int szOsFile; /* Size of subclassed sqlite3_file */ 1220: int mxPathname; /* Maximum file pathname length */ 1221: sqlite3_vfs *pNext; /* Next registered VFS */ 1222: const char *zName; /* Name of this virtual file system */ 1223: void *pAppData; /* Pointer to application-specific data */ 1224: int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1225: int flags, int *pOutFlags); 1226: int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1227: int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1228: int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1229: void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1230: void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1231: void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1232: void (*xDlClose)(sqlite3_vfs*, void*); 1233: int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1234: int (*xSleep)(sqlite3_vfs*, int microseconds); 1235: int (*xCurrentTime)(sqlite3_vfs*, double*); 1236: int (*xGetLastError)(sqlite3_vfs*, int, char *); 1237: /* 1238: ** The methods above are in version 1 of the sqlite_vfs object 1239: ** definition. Those that follow are added in version 2 or later 1240: */ 1241: int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1242: /* 1243: ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1244: ** Those below are for version 3 and greater. 1245: */ 1246: int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1247: sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1248: const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1249: /* 1250: ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1251: ** New fields may be appended in future versions. The iVersion 1252: ** value will increment whenever this happens. 1253: */ 1254: }; 1255: 1256: /* 1257: ** CAPI3REF: Flags for the xAccess VFS method 1258: ** 1259: ** These integer constants can be used as the third parameter to 1260: ** the xAccess method of an [sqlite3_vfs] object. They determine 1261: ** what kind of permissions the xAccess method is looking for. 1262: ** With SQLITE_ACCESS_EXISTS, the xAccess method 1263: ** simply checks whether the file exists. 1264: ** With SQLITE_ACCESS_READWRITE, the xAccess method 1265: ** checks whether the named directory is both readable and writable 1266: ** (in other words, if files can be added, removed, and renamed within 1267: ** the directory). 1268: ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1269: ** [temp_store_directory pragma], though this could change in a future 1270: ** release of SQLite. 1271: ** With SQLITE_ACCESS_READ, the xAccess method 1272: ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1273: ** currently unused, though it might be used in a future release of 1274: ** SQLite. 1275: */ 1276: #define SQLITE_ACCESS_EXISTS 0 1277: #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1278: #define SQLITE_ACCESS_READ 2 /* Unused */ 1279: 1280: /* 1281: ** CAPI3REF: Flags for the xShmLock VFS method 1282: ** 1283: ** These integer constants define the various locking operations 1284: ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1285: ** following are the only legal combinations of flags to the 1286: ** xShmLock method: 1287: ** 1288: ** <ul> 1289: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1290: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1291: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1292: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1293: ** </ul> 1294: ** 1295: ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1296: ** was given on the corresponding lock. 1297: ** 1298: ** The xShmLock method can transition between unlocked and SHARED or 1299: ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1300: ** and EXCLUSIVE. 1301: */ 1302: #define SQLITE_SHM_UNLOCK 1 1303: #define SQLITE_SHM_LOCK 2 1304: #define SQLITE_SHM_SHARED 4 1305: #define SQLITE_SHM_EXCLUSIVE 8 1306: 1307: /* 1308: ** CAPI3REF: Maximum xShmLock index 1309: ** 1310: ** The xShmLock method on [sqlite3_io_methods] may use values 1311: ** between 0 and this upper bound as its "offset" argument. 1312: ** The SQLite core will never attempt to acquire or release a 1313: ** lock outside of this range 1314: */ 1315: #define SQLITE_SHM_NLOCK 8 1316: 1317: 1318: /* 1319: ** CAPI3REF: Initialize The SQLite Library 1320: ** 1321: ** ^The sqlite3_initialize() routine initializes the 1322: ** SQLite library. ^The sqlite3_shutdown() routine 1323: ** deallocates any resources that were allocated by sqlite3_initialize(). 1324: ** These routines are designed to aid in process initialization and 1325: ** shutdown on embedded systems. Workstation applications using 1326: ** SQLite normally do not need to invoke either of these routines. 1327: ** 1328: ** A call to sqlite3_initialize() is an "effective" call if it is 1329: ** the first time sqlite3_initialize() is invoked during the lifetime of 1330: ** the process, or if it is the first time sqlite3_initialize() is invoked 1331: ** following a call to sqlite3_shutdown(). ^(Only an effective call 1332: ** of sqlite3_initialize() does any initialization. All other calls 1333: ** are harmless no-ops.)^ 1334: ** 1335: ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1336: ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1337: ** an effective call to sqlite3_shutdown() does any deinitialization. 1338: ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1339: ** 1340: ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1341: ** is not. The sqlite3_shutdown() interface must only be called from a 1342: ** single thread. All open [database connections] must be closed and all 1343: ** other SQLite resources must be deallocated prior to invoking 1344: ** sqlite3_shutdown(). 1345: ** 1346: ** Among other things, ^sqlite3_initialize() will invoke 1347: ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1348: ** will invoke sqlite3_os_end(). 1349: ** 1350: ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1351: ** ^If for some reason, sqlite3_initialize() is unable to initialize 1352: ** the library (perhaps it is unable to allocate a needed resource such 1353: ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1354: ** 1355: ** ^The sqlite3_initialize() routine is called internally by many other 1356: ** SQLite interfaces so that an application usually does not need to 1357: ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1358: ** calls sqlite3_initialize() so the SQLite library will be automatically 1359: ** initialized when [sqlite3_open()] is called if it has not be initialized 1360: ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1361: ** compile-time option, then the automatic calls to sqlite3_initialize() 1362: ** are omitted and the application must call sqlite3_initialize() directly 1363: ** prior to using any other SQLite interface. For maximum portability, 1364: ** it is recommended that applications always invoke sqlite3_initialize() 1365: ** directly prior to using any other SQLite interface. Future releases 1366: ** of SQLite may require this. In other words, the behavior exhibited 1367: ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1368: ** default behavior in some future release of SQLite. 1369: ** 1370: ** The sqlite3_os_init() routine does operating-system specific 1371: ** initialization of the SQLite library. The sqlite3_os_end() 1372: ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1373: ** performed by these routines include allocation or deallocation 1374: ** of static resources, initialization of global variables, 1375: ** setting up a default [sqlite3_vfs] module, or setting up 1376: ** a default configuration using [sqlite3_config()]. 1377: ** 1378: ** The application should never invoke either sqlite3_os_init() 1379: ** or sqlite3_os_end() directly. The application should only invoke 1380: ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1381: ** interface is called automatically by sqlite3_initialize() and 1382: ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1383: ** implementations for sqlite3_os_init() and sqlite3_os_end() 1384: ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1385: ** When [custom builds | built for other platforms] 1386: ** (using the [SQLITE_OS_OTHER=1] compile-time 1387: ** option) the application must supply a suitable implementation for 1388: ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1389: ** implementation of sqlite3_os_init() or sqlite3_os_end() 1390: ** must return [SQLITE_OK] on success and some other [error code] upon 1391: ** failure. 1392: */ 1393: SQLITE_API int sqlite3_initialize(void); 1394: SQLITE_API int sqlite3_shutdown(void); 1395: SQLITE_API int sqlite3_os_init(void); 1396: SQLITE_API int sqlite3_os_end(void); 1397: 1398: /* 1399: ** CAPI3REF: Configuring The SQLite Library 1400: ** 1401: ** The sqlite3_config() interface is used to make global configuration 1402: ** changes to SQLite in order to tune SQLite to the specific needs of 1403: ** the application. The default configuration is recommended for most 1404: ** applications and so this routine is usually not necessary. It is 1405: ** provided to support rare applications with unusual needs. 1406: ** 1407: ** <b>The sqlite3_config() interface is not threadsafe. The application 1408: ** must ensure that no other SQLite interfaces are invoked by other 1409: ** threads while sqlite3_config() is running.</b> 1410: ** 1411: ** The sqlite3_config() interface 1412: ** may only be invoked prior to library initialization using 1413: ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1414: ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1415: ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1416: ** Note, however, that ^sqlite3_config() can be called as part of the 1417: ** implementation of an application-defined [sqlite3_os_init()]. 1418: ** 1419: ** The first argument to sqlite3_config() is an integer 1420: ** [configuration option] that determines 1421: ** what property of SQLite is to be configured. Subsequent arguments 1422: ** vary depending on the [configuration option] 1423: ** in the first argument. 1424: ** 1425: ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1426: ** ^If the option is unknown or SQLite is unable to set the option 1427: ** then this routine returns a non-zero [error code]. 1428: */ 1429: SQLITE_API int sqlite3_config(int, ...); 1430: 1431: /* 1432: ** CAPI3REF: Configure database connections 1433: ** METHOD: sqlite3 1434: ** 1435: ** The sqlite3_db_config() interface is used to make configuration 1436: ** changes to a [database connection]. The interface is similar to 1437: ** [sqlite3_config()] except that the changes apply to a single 1438: ** [database connection] (specified in the first argument). 1439: ** 1440: ** The second argument to sqlite3_db_config(D,V,...) is the 1441: ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1442: ** that indicates what aspect of the [database connection] is being configured. 1443: ** Subsequent arguments vary depending on the configuration verb. 1444: ** 1445: ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1446: ** the call is considered successful. 1447: */ 1448: SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1449: 1450: /* 1451: ** CAPI3REF: Memory Allocation Routines 1452: ** 1453: ** An instance of this object defines the interface between SQLite 1454: ** and low-level memory allocation routines. 1455: ** 1456: ** This object is used in only one place in the SQLite interface. 1457: ** A pointer to an instance of this object is the argument to 1458: ** [sqlite3_config()] when the configuration option is 1459: ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1460: ** By creating an instance of this object 1461: ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1462: ** during configuration, an application can specify an alternative 1463: ** memory allocation subsystem for SQLite to use for all of its 1464: ** dynamic memory needs. 1465: ** 1466: ** Note that SQLite comes with several [built-in memory allocators] 1467: ** that are perfectly adequate for the overwhelming majority of applications 1468: ** and that this object is only useful to a tiny minority of applications 1469: ** with specialized memory allocation requirements. This object is 1470: ** also used during testing of SQLite in order to specify an alternative 1471: ** memory allocator that simulates memory out-of-memory conditions in 1472: ** order to verify that SQLite recovers gracefully from such 1473: ** conditions. 1474: ** 1475: ** The xMalloc, xRealloc, and xFree methods must work like the 1476: ** malloc(), realloc() and free() functions from the standard C library. 1477: ** ^SQLite guarantees that the second argument to 1478: ** xRealloc is always a value returned by a prior call to xRoundup. 1479: ** 1480: ** xSize should return the allocated size of a memory allocation 1481: ** previously obtained from xMalloc or xRealloc. The allocated size 1482: ** is always at least as big as the requested size but may be larger. 1483: ** 1484: ** The xRoundup method returns what would be the allocated size of 1485: ** a memory allocation given a particular requested size. Most memory 1486: ** allocators round up memory allocations at least to the next multiple 1487: ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1488: ** Every memory allocation request coming in through [sqlite3_malloc()] 1489: ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1490: ** that causes the corresponding memory allocation to fail. 1491: ** 1492: ** The xInit method initializes the memory allocator. For example, 1493: ** it might allocate any require mutexes or initialize internal data 1494: ** structures. The xShutdown method is invoked (indirectly) by 1495: ** [sqlite3_shutdown()] and should deallocate any resources acquired 1496: ** by xInit. The pAppData pointer is used as the only parameter to 1497: ** xInit and xShutdown. 1498: ** 1499: ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1500: ** the xInit method, so the xInit method need not be threadsafe. The 1501: ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1502: ** not need to be threadsafe either. For all other methods, SQLite 1503: ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1504: ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1505: ** it is by default) and so the methods are automatically serialized. 1506: ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1507: ** methods must be threadsafe or else make their own arrangements for 1508: ** serialization. 1509: ** 1510: ** SQLite will never invoke xInit() more than once without an intervening 1511: ** call to xShutdown(). 1512: */ 1513: typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1514: struct sqlite3_mem_methods { 1515: void *(*xMalloc)(int); /* Memory allocation function */ 1516: void (*xFree)(void*); /* Free a prior allocation */ 1517: void *(*xRealloc)(void*,int); /* Resize an allocation */ 1518: int (*xSize)(void*); /* Return the size of an allocation */ 1519: int (*xRoundup)(int); /* Round up request size to allocation size */ 1520: int (*xInit)(void*); /* Initialize the memory allocator */ 1521: void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1522: void *pAppData; /* Argument to xInit() and xShutdown() */ 1523: }; 1524: 1525: /* 1526: ** CAPI3REF: Configuration Options 1527: ** KEYWORDS: {configuration option} 1528: ** 1529: ** These constants are the available integer configuration options that 1530: ** can be passed as the first argument to the [sqlite3_config()] interface. 1531: ** 1532: ** New configuration options may be added in future releases of SQLite. 1533: ** Existing configuration options might be discontinued. Applications 1534: ** should check the return code from [sqlite3_config()] to make sure that 1535: ** the call worked. The [sqlite3_config()] interface will return a 1536: ** non-zero [error code] if a discontinued or unsupported configuration option 1537: ** is invoked. 1538: ** 1539: ** <dl> 1540: ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1541: ** <dd>There are no arguments to this option. ^This option sets the 1542: ** [threading mode] to Single-thread. In other words, it disables 1543: ** all mutexing and puts SQLite into a mode where it can only be used 1544: ** by a single thread. ^If SQLite is compiled with 1545: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1546: ** it is not possible to change the [threading mode] from its default 1547: ** value of Single-thread and so [sqlite3_config()] will return 1548: ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1549: ** configuration option.</dd> 1550: ** 1551: ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1552: ** <dd>There are no arguments to this option. ^This option sets the 1553: ** [threading mode] to Multi-thread. In other words, it disables 1554: ** mutexing on [database connection] and [prepared statement] objects. 1555: ** The application is responsible for serializing access to 1556: ** [database connections] and [prepared statements]. But other mutexes 1557: ** are enabled so that SQLite will be safe to use in a multi-threaded 1558: ** environment as long as no two threads attempt to use the same 1559: ** [database connection] at the same time. ^If SQLite is compiled with 1560: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1561: ** it is not possible to set the Multi-thread [threading mode] and 1562: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1563: ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1564: ** 1565: ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1566: ** <dd>There are no arguments to this option. ^This option sets the 1567: ** [threading mode] to Serialized. In other words, this option enables 1568: ** all mutexes including the recursive 1569: ** mutexes on [database connection] and [prepared statement] objects. 1570: ** In this mode (which is the default when SQLite is compiled with 1571: ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1572: ** to [database connections] and [prepared statements] so that the 1573: ** application is free to use the same [database connection] or the 1574: ** same [prepared statement] in different threads at the same time. 1575: ** ^If SQLite is compiled with 1576: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1577: ** it is not possible to set the Serialized [threading mode] and 1578: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1579: ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1580: ** 1581: ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1582: ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1583: ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1584: ** The argument specifies 1585: ** alternative low-level memory allocation routines to be used in place of 1586: ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1587: ** its own private copy of the content of the [sqlite3_mem_methods] structure 1588: ** before the [sqlite3_config()] call returns.</dd> 1589: ** 1590: ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1591: ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1592: ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1593: ** The [sqlite3_mem_methods] 1594: ** structure is filled with the currently defined memory allocation routines.)^ 1595: ** This option can be used to overload the default memory allocation 1596: ** routines with a wrapper that simulations memory allocation failure or 1597: ** tracks memory usage, for example. </dd> 1598: ** 1599: ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1600: ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1601: ** interpreted as a boolean, which enables or disables the collection of 1602: ** memory allocation statistics. ^(When memory allocation statistics are 1603: ** disabled, the following SQLite interfaces become non-operational: 1604: ** <ul> 1605: ** <li> [sqlite3_memory_used()] 1606: ** <li> [sqlite3_memory_highwater()] 1607: ** <li> [sqlite3_soft_heap_limit64()] 1608: ** <li> [sqlite3_status64()] 1609: ** </ul>)^ 1610: ** ^Memory allocation statistics are enabled by default unless SQLite is 1611: ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1612: ** allocation statistics are disabled by default. 1613: ** </dd> 1614: ** 1615: ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1616: ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1617: ** that SQLite can use for scratch memory. ^(There are three arguments 1618: ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1619: ** aligned memory buffer from which the scratch allocations will be 1620: ** drawn, the size of each scratch allocation (sz), 1621: ** and the maximum number of scratch allocations (N).)^ 1622: ** The first argument must be a pointer to an 8-byte aligned buffer 1623: ** of at least sz*N bytes of memory. 1624: ** ^SQLite will not use more than one scratch buffers per thread. 1625: ** ^SQLite will never request a scratch buffer that is more than 6 1626: ** times the database page size. 1627: ** ^If SQLite needs needs additional 1628: ** scratch memory beyond what is provided by this configuration option, then 1629: ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1630: ** ^When the application provides any amount of scratch memory using 1631: ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1632: ** [sqlite3_malloc|heap allocations]. 1633: ** This can help [Robson proof|prevent memory allocation failures] due to heap 1634: ** fragmentation in low-memory embedded systems. 1635: ** </dd> 1636: ** 1637: ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1638: ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1639: ** that SQLite can use for the database page cache with the default page 1640: ** cache implementation. 1641: ** This configuration option is a no-op if an application-define page 1642: ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1643: ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1644: ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1645: ** and the number of cache lines (N). 1646: ** The sz argument should be the size of the largest database page 1647: ** (a power of two between 512 and 65536) plus some extra bytes for each 1648: ** page header. ^The number of extra bytes needed by the page header 1649: ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1650: ** ^It is harmless, apart from the wasted memory, 1651: ** for the sz parameter to be larger than necessary. The pMem 1652: ** argument must be either a NULL pointer or a pointer to an 8-byte 1653: ** aligned block of memory of at least sz*N bytes, otherwise 1654: ** subsequent behavior is undefined. 1655: ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1656: ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1657: ** a page cache line is larger than sz bytes or if all of the pMem buffer 1658: ** is exhausted. 1659: ** ^If pMem is NULL and N is non-zero, then each database connection 1660: ** does an initial bulk allocation for page cache memory 1661: ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1662: ** of -1024*N bytes if N is negative, . ^If additional 1663: ** page cache memory is needed beyond what is provided by the initial 1664: ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1665: ** additional cache line. </dd> 1666: ** 1667: ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1668: ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1669: ** that SQLite will use for all of its dynamic memory allocation needs 1670: ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1671: ** [SQLITE_CONFIG_PAGECACHE]. 1672: ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1673: ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1674: ** [SQLITE_ERROR] if invoked otherwise. 1675: ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1676: ** An 8-byte aligned pointer to the memory, 1677: ** the number of bytes in the memory buffer, and the minimum allocation size. 1678: ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1679: ** to using its default memory allocator (the system malloc() implementation), 1680: ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1681: ** memory pointer is not NULL then the alternative memory 1682: ** allocator is engaged to handle all of SQLites memory allocation needs. 1683: ** The first pointer (the memory pointer) must be aligned to an 8-byte 1684: ** boundary or subsequent behavior of SQLite will be undefined. 1685: ** The minimum allocation size is capped at 2**12. Reasonable values 1686: ** for the minimum allocation size are 2**5 through 2**8.</dd> 1687: ** 1688: ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1689: ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1690: ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1691: ** The argument specifies alternative low-level mutex routines to be used 1692: ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1693: ** the content of the [sqlite3_mutex_methods] structure before the call to 1694: ** [sqlite3_config()] returns. ^If SQLite is compiled with 1695: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1696: ** the entire mutexing subsystem is omitted from the build and hence calls to 1697: ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1698: ** return [SQLITE_ERROR].</dd> 1699: ** 1700: ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1701: ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1702: ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1703: ** [sqlite3_mutex_methods] 1704: ** structure is filled with the currently defined mutex routines.)^ 1705: ** This option can be used to overload the default mutex allocation 1706: ** routines with a wrapper used to track mutex usage for performance 1707: ** profiling or testing, for example. ^If SQLite is compiled with 1708: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1709: ** the entire mutexing subsystem is omitted from the build and hence calls to 1710: ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1711: ** return [SQLITE_ERROR].</dd> 1712: ** 1713: ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1714: ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1715: ** the default size of lookaside memory on each [database connection]. 1716: ** The first argument is the 1717: ** size of each lookaside buffer slot and the second is the number of 1718: ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1719: ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1720: ** option to [sqlite3_db_config()] can be used to change the lookaside 1721: ** configuration on individual connections.)^ </dd> 1722: ** 1723: ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1724: ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1725: ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1726: ** the interface to a custom page cache implementation.)^ 1727: ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1728: ** 1729: ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1730: ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1731: ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1732: ** the current page cache implementation into that object.)^ </dd> 1733: ** 1734: ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1735: ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1736: ** global [error log]. 1737: ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1738: ** function with a call signature of void(*)(void*,int,const char*), 1739: ** and a pointer to void. ^If the function pointer is not NULL, it is 1740: ** invoked by [sqlite3_log()] to process each logging event. ^If the 1741: ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1742: ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1743: ** passed through as the first parameter to the application-defined logger 1744: ** function whenever that function is invoked. ^The second parameter to 1745: ** the logger function is a copy of the first parameter to the corresponding 1746: ** [sqlite3_log()] call and is intended to be a [result code] or an 1747: ** [extended result code]. ^The third parameter passed to the logger is 1748: ** log message after formatting via [sqlite3_snprintf()]. 1749: ** The SQLite logging interface is not reentrant; the logger function 1750: ** supplied by the application must not invoke any SQLite interface. 1751: ** In a multi-threaded application, the application-defined logger 1752: ** function must be threadsafe. </dd> 1753: ** 1754: ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1755: ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1756: ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1757: ** then URI handling is globally disabled.)^ ^If URI handling is globally 1758: ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1759: ** [sqlite3_open16()] or 1760: ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1761: ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1762: ** connection is opened. ^If it is globally disabled, filenames are 1763: ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1764: ** database connection is opened. ^(By default, URI handling is globally 1765: ** disabled. The default value may be changed by compiling with the 1766: ** [SQLITE_USE_URI] symbol defined.)^ 1767: ** 1768: ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1769: ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1770: ** argument which is interpreted as a boolean in order to enable or disable 1771: ** the use of covering indices for full table scans in the query optimizer. 1772: ** ^The default setting is determined 1773: ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1774: ** if that compile-time option is omitted. 1775: ** The ability to disable the use of covering indices for full table scans 1776: ** is because some incorrectly coded legacy applications might malfunction 1777: ** when the optimization is enabled. Providing the ability to 1778: ** disable the optimization allows the older, buggy application code to work 1779: ** without change even with newer versions of SQLite. 1780: ** 1781: ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1782: ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1783: ** <dd> These options are obsolete and should not be used by new code. 1784: ** They are retained for backwards compatibility but are now no-ops. 1785: ** </dd> 1786: ** 1787: ** [[SQLITE_CONFIG_SQLLOG]] 1788: ** <dt>SQLITE_CONFIG_SQLLOG 1789: ** <dd>This option is only available if sqlite is compiled with the 1790: ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1791: ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1792: ** The second should be of type (void*). The callback is invoked by the library 1793: ** in three separate circumstances, identified by the value passed as the 1794: ** fourth parameter. If the fourth parameter is 0, then the database connection 1795: ** passed as the second argument has just been opened. The third argument 1796: ** points to a buffer containing the name of the main database file. If the 1797: ** fourth parameter is 1, then the SQL statement that the third parameter 1798: ** points to has just been executed. Or, if the fourth parameter is 2, then 1799: ** the connection being passed as the second parameter is being closed. The 1800: ** third parameter is passed NULL In this case. An example of using this 1801: ** configuration option can be seen in the "test_sqllog.c" source file in 1802: ** the canonical SQLite source tree.</dd> 1803: ** 1804: ** [[SQLITE_CONFIG_MMAP_SIZE]] 1805: ** <dt>SQLITE_CONFIG_MMAP_SIZE 1806: ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1807: ** that are the default mmap size limit (the default setting for 1808: ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1809: ** ^The default setting can be overridden by each database connection using 1810: ** either the [PRAGMA mmap_size] command, or by using the 1811: ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1812: ** will be silently truncated if necessary so that it does not exceed the 1813: ** compile-time maximum mmap size set by the 1814: ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1815: ** ^If either argument to this option is negative, then that argument is 1816: ** changed to its compile-time default. 1817: ** 1818: ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1819: ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1820: ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1821: ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1822: ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1823: ** that specifies the maximum size of the created heap. 1824: ** 1825: ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1826: ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1827: ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1828: ** is a pointer to an integer and writes into that integer the number of extra 1829: ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1830: ** The amount of extra space required can change depending on the compiler, 1831: ** target platform, and SQLite version. 1832: ** 1833: ** [[SQLITE_CONFIG_PMASZ]] 1834: ** <dt>SQLITE_CONFIG_PMASZ 1835: ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1836: ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1837: ** sorter to that integer. The default minimum PMA Size is set by the 1838: ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1839: ** to help with sort operations when multithreaded sorting 1840: ** is enabled (using the [PRAGMA threads] command) and the amount of content 1841: ** to be sorted exceeds the page size times the minimum of the 1842: ** [PRAGMA cache_size] setting and this value. 1843: ** 1844: ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1845: ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1846: ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1847: ** becomes the [statement journal] spill-to-disk threshold. 1848: ** [Statement journals] are held in memory until their size (in bytes) 1849: ** exceeds this threshold, at which point they are written to disk. 1850: ** Or if the threshold is -1, statement journals are always held 1851: ** exclusively in memory. 1852: ** Since many statement journals never become large, setting the spill 1853: ** threshold to a value such as 64KiB can greatly reduce the amount of 1854: ** I/O required to support statement rollback. 1855: ** The default value for this setting is controlled by the 1856: ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1857: ** </dl> 1858: */ 1859: #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1860: #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1861: #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1862: #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1863: #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1864: #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1865: #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1866: #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1867: #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1868: #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1869: #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1870: /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1871: #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1872: #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1873: #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1874: #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1875: #define SQLITE_CONFIG_URI 17 /* int */ 1876: #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1877: #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1878: #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1879: #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1880: #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1881: #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1882: #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1883: #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1884: #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1885: 1886: /* 1887: ** CAPI3REF: Database Connection Configuration Options 1888: ** 1889: ** These constants are the available integer configuration options that 1890: ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1891: ** 1892: ** New configuration options may be added in future releases of SQLite. 1893: ** Existing configuration options might be discontinued. Applications 1894: ** should check the return code from [sqlite3_db_config()] to make sure that 1895: ** the call worked. ^The [sqlite3_db_config()] interface will return a 1896: ** non-zero [error code] if a discontinued or unsupported configuration option 1897: ** is invoked. 1898: ** 1899: ** <dl> 1900: ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1901: ** <dd> ^This option takes three additional arguments that determine the 1902: ** [lookaside memory allocator] configuration for the [database connection]. 1903: ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1904: ** pointer to a memory buffer to use for lookaside memory. 1905: ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1906: ** may be NULL in which case SQLite will allocate the 1907: ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1908: ** size of each lookaside buffer slot. ^The third argument is the number of 1909: ** slots. The size of the buffer in the first argument must be greater than 1910: ** or equal to the product of the second and third arguments. The buffer 1911: ** must be aligned to an 8-byte boundary. ^If the second argument to 1912: ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1913: ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1914: ** configuration for a database connection can only be changed when that 1915: ** connection is not currently using lookaside memory, or in other words 1916: ** when the "current value" returned by 1917: ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1918: ** Any attempt to change the lookaside memory configuration when lookaside 1919: ** memory is in use leaves the configuration unchanged and returns 1920: ** [SQLITE_BUSY].)^</dd> 1921: ** 1922: ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1923: ** <dd> ^This option is used to enable or disable the enforcement of 1924: ** [foreign key constraints]. There should be two additional arguments. 1925: ** The first argument is an integer which is 0 to disable FK enforcement, 1926: ** positive to enable FK enforcement or negative to leave FK enforcement 1927: ** unchanged. The second parameter is a pointer to an integer into which 1928: ** is written 0 or 1 to indicate whether FK enforcement is off or on 1929: ** following this call. The second parameter may be a NULL pointer, in 1930: ** which case the FK enforcement setting is not reported back. </dd> 1931: ** 1932: ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1933: ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1934: ** There should be two additional arguments. 1935: ** The first argument is an integer which is 0 to disable triggers, 1936: ** positive to enable triggers or negative to leave the setting unchanged. 1937: ** The second parameter is a pointer to an integer into which 1938: ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1939: ** following this call. The second parameter may be a NULL pointer, in 1940: ** which case the trigger setting is not reported back. </dd> 1941: ** 1942: ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1943: ** <dd> ^This option is used to enable or disable the two-argument 1944: ** version of the [fts3_tokenizer()] function which is part of the 1945: ** [FTS3] full-text search engine extension. 1946: ** There should be two additional arguments. 1947: ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1948: ** positive to enable fts3_tokenizer() or negative to leave the setting 1949: ** unchanged. 1950: ** The second parameter is a pointer to an integer into which 1951: ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1952: ** following this call. The second parameter may be a NULL pointer, in 1953: ** which case the new setting is not reported back. </dd> 1954: ** 1955: ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 1956: ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 1957: ** interface independently of the [load_extension()] SQL function. 1958: ** The [sqlite3_enable_load_extension()] API enables or disables both the 1959: ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 1960: ** There should be two additional arguments. 1961: ** When the first argument to this interface is 1, then only the C-API is 1962: ** enabled and the SQL function remains disabled. If the first argument to 1963: ** this interface is 0, then both the C-API and the SQL function are disabled. 1964: ** If the first argument is -1, then no changes are made to state of either the 1965: ** C-API or the SQL function. 1966: ** The second parameter is a pointer to an integer into which 1967: ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 1968: ** is disabled or enabled following this call. The second parameter may 1969: ** be a NULL pointer, in which case the new setting is not reported back. 1970: ** </dd> 1971: ** 1972: ** </dl> 1973: */ 1974: #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1975: #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1976: #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1977: #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 1978: #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 1979: 1980: 1981: /* 1982: ** CAPI3REF: Enable Or Disable Extended Result Codes 1983: ** METHOD: sqlite3 1984: ** 1985: ** ^The sqlite3_extended_result_codes() routine enables or disables the 1986: ** [extended result codes] feature of SQLite. ^The extended result 1987: ** codes are disabled by default for historical compatibility. 1988: */ 1989: SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 1990: 1991: /* 1992: ** CAPI3REF: Last Insert Rowid 1993: ** METHOD: sqlite3 1994: ** 1995: ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1996: ** has a unique 64-bit signed 1997: ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1998: ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1999: ** names are not also used by explicitly declared columns. ^If 2000: ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2001: ** is another alias for the rowid. 2002: ** 2003: ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 2004: ** most recent successful [INSERT] into a rowid table or [virtual table] 2005: ** on database connection D. 2006: ** ^Inserts into [WITHOUT ROWID] tables are not recorded. 2007: ** ^If no successful [INSERT]s into rowid tables 2008: ** have ever occurred on the database connection D, 2009: ** then sqlite3_last_insert_rowid(D) returns zero. 2010: ** 2011: ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 2012: ** method, then this routine will return the [rowid] of the inserted 2013: ** row as long as the trigger or virtual table method is running. 2014: ** But once the trigger or virtual table method ends, the value returned 2015: ** by this routine reverts to what it was before the trigger or virtual 2016: ** table method began.)^ 2017: ** 2018: ** ^An [INSERT] that fails due to a constraint violation is not a 2019: ** successful [INSERT] and does not change the value returned by this 2020: ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2021: ** and INSERT OR ABORT make no changes to the return value of this 2022: ** routine when their insertion fails. ^(When INSERT OR REPLACE 2023: ** encounters a constraint violation, it does not fail. The 2024: ** INSERT continues to completion after deleting rows that caused 2025: ** the constraint problem so INSERT OR REPLACE will always change 2026: ** the return value of this interface.)^ 2027: ** 2028: ** ^For the purposes of this routine, an [INSERT] is considered to 2029: ** be successful even if it is subsequently rolled back. 2030: ** 2031: ** This function is accessible to SQL statements via the 2032: ** [last_insert_rowid() SQL function]. 2033: ** 2034: ** If a separate thread performs a new [INSERT] on the same 2035: ** database connection while the [sqlite3_last_insert_rowid()] 2036: ** function is running and thus changes the last insert [rowid], 2037: ** then the value returned by [sqlite3_last_insert_rowid()] is 2038: ** unpredictable and might not equal either the old or the new 2039: ** last insert [rowid]. 2040: */ 2041: SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2042: 2043: /* 2044: ** CAPI3REF: Count The Number Of Rows Modified 2045: ** METHOD: sqlite3 2046: ** 2047: ** ^This function returns the number of rows modified, inserted or 2048: ** deleted by the most recently completed INSERT, UPDATE or DELETE 2049: ** statement on the database connection specified by the only parameter. 2050: ** ^Executing any other type of SQL statement does not modify the value 2051: ** returned by this function. 2052: ** 2053: ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2054: ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2055: ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2056: ** 2057: ** Changes to a view that are intercepted by 2058: ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2059: ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2060: ** DELETE statement run on a view is always zero. Only changes made to real 2061: ** tables are counted. 2062: ** 2063: ** Things are more complicated if the sqlite3_changes() function is 2064: ** executed while a trigger program is running. This may happen if the 2065: ** program uses the [changes() SQL function], or if some other callback 2066: ** function invokes sqlite3_changes() directly. Essentially: 2067: ** 2068: ** <ul> 2069: ** <li> ^(Before entering a trigger program the value returned by 2070: ** sqlite3_changes() function is saved. After the trigger program 2071: ** has finished, the original value is restored.)^ 2072: ** 2073: ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2074: ** statement sets the value returned by sqlite3_changes() 2075: ** upon completion as normal. Of course, this value will not include 2076: ** any changes performed by sub-triggers, as the sqlite3_changes() 2077: ** value will be saved and restored after each sub-trigger has run.)^ 2078: ** </ul> 2079: ** 2080: ** ^This means that if the changes() SQL function (or similar) is used 2081: ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2082: ** returns the value as set when the calling statement began executing. 2083: ** ^If it is used by the second or subsequent such statement within a trigger 2084: ** program, the value returned reflects the number of rows modified by the 2085: ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2086: ** 2087: ** See also the [sqlite3_total_changes()] interface, the 2088: ** [count_changes pragma], and the [changes() SQL function]. 2089: ** 2090: ** If a separate thread makes changes on the same database connection 2091: ** while [sqlite3_changes()] is running then the value returned 2092: ** is unpredictable and not meaningful. 2093: */ 2094: SQLITE_API int sqlite3_changes(sqlite3*); 2095: 2096: /* 2097: ** CAPI3REF: Total Number Of Rows Modified 2098: ** METHOD: sqlite3 2099: ** 2100: ** ^This function returns the total number of rows inserted, modified or 2101: ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2102: ** since the database connection was opened, including those executed as 2103: ** part of trigger programs. ^Executing any other type of SQL statement 2104: ** does not affect the value returned by sqlite3_total_changes(). 2105: ** 2106: ** ^Changes made as part of [foreign key actions] are included in the 2107: ** count, but those made as part of REPLACE constraint resolution are 2108: ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2109: ** are not counted. 2110: ** 2111: ** See also the [sqlite3_changes()] interface, the 2112: ** [count_changes pragma], and the [total_changes() SQL function]. 2113: ** 2114: ** If a separate thread makes changes on the same database connection 2115: ** while [sqlite3_total_changes()] is running then the value 2116: ** returned is unpredictable and not meaningful. 2117: */ 2118: SQLITE_API int sqlite3_total_changes(sqlite3*); 2119: 2120: /* 2121: ** CAPI3REF: Interrupt A Long-Running Query 2122: ** METHOD: sqlite3 2123: ** 2124: ** ^This function causes any pending database operation to abort and 2125: ** return at its earliest opportunity. This routine is typically 2126: ** called in response to a user action such as pressing "Cancel" 2127: ** or Ctrl-C where the user wants a long query operation to halt 2128: ** immediately. 2129: ** 2130: ** ^It is safe to call this routine from a thread different from the 2131: ** thread that is currently running the database operation. But it 2132: ** is not safe to call this routine with a [database connection] that 2133: ** is closed or might close before sqlite3_interrupt() returns. 2134: ** 2135: ** ^If an SQL operation is very nearly finished at the time when 2136: ** sqlite3_interrupt() is called, then it might not have an opportunity 2137: ** to be interrupted and might continue to completion. 2138: ** 2139: ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2140: ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2141: ** that is inside an explicit transaction, then the entire transaction 2142: ** will be rolled back automatically. 2143: ** 2144: ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2145: ** SQL statements on [database connection] D complete. ^Any new SQL statements 2146: ** that are started after the sqlite3_interrupt() call and before the 2147: ** running statements reaches zero are interrupted as if they had been 2148: ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2149: ** that are started after the running statement count reaches zero are 2150: ** not effected by the sqlite3_interrupt(). 2151: ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2152: ** SQL statements is a no-op and has no effect on SQL statements 2153: ** that are started after the sqlite3_interrupt() call returns. 2154: ** 2155: ** If the database connection closes while [sqlite3_interrupt()] 2156: ** is running then bad things will likely happen. 2157: */ 2158: SQLITE_API void sqlite3_interrupt(sqlite3*); 2159: 2160: /* 2161: ** CAPI3REF: Determine If An SQL Statement Is Complete 2162: ** 2163: ** These routines are useful during command-line input to determine if the 2164: ** currently entered text seems to form a complete SQL statement or 2165: ** if additional input is needed before sending the text into 2166: ** SQLite for parsing. ^These routines return 1 if the input string 2167: ** appears to be a complete SQL statement. ^A statement is judged to be 2168: ** complete if it ends with a semicolon token and is not a prefix of a 2169: ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2170: ** string literals or quoted identifier names or comments are not 2171: ** independent tokens (they are part of the token in which they are 2172: ** embedded) and thus do not count as a statement terminator. ^Whitespace 2173: ** and comments that follow the final semicolon are ignored. 2174: ** 2175: ** ^These routines return 0 if the statement is incomplete. ^If a 2176: ** memory allocation fails, then SQLITE_NOMEM is returned. 2177: ** 2178: ** ^These routines do not parse the SQL statements thus 2179: ** will not detect syntactically incorrect SQL. 2180: ** 2181: ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2182: ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2183: ** automatically by sqlite3_complete16(). If that initialization fails, 2184: ** then the return value from sqlite3_complete16() will be non-zero 2185: ** regardless of whether or not the input SQL is complete.)^ 2186: ** 2187: ** The input to [sqlite3_complete()] must be a zero-terminated 2188: ** UTF-8 string. 2189: ** 2190: ** The input to [sqlite3_complete16()] must be a zero-terminated 2191: ** UTF-16 string in native byte order. 2192: */ 2193: SQLITE_API int sqlite3_complete(const char *sql); 2194: SQLITE_API int sqlite3_complete16(const void *sql); 2195: 2196: /* 2197: ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2198: ** KEYWORDS: {busy-handler callback} {busy handler} 2199: ** METHOD: sqlite3 2200: ** 2201: ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2202: ** that might be invoked with argument P whenever 2203: ** an attempt is made to access a database table associated with 2204: ** [database connection] D when another thread 2205: ** or process has the table locked. 2206: ** The sqlite3_busy_handler() interface is used to implement 2207: ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2208: ** 2209: ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2210: ** is returned immediately upon encountering the lock. ^If the busy callback 2211: ** is not NULL, then the callback might be invoked with two arguments. 2212: ** 2213: ** ^The first argument to the busy handler is a copy of the void* pointer which 2214: ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2215: ** the busy handler callback is the number of times that the busy handler has 2216: ** been invoked previously for the same locking event. ^If the 2217: ** busy callback returns 0, then no additional attempts are made to 2218: ** access the database and [SQLITE_BUSY] is returned 2219: ** to the application. 2220: ** ^If the callback returns non-zero, then another attempt 2221: ** is made to access the database and the cycle repeats. 2222: ** 2223: ** The presence of a busy handler does not guarantee that it will be invoked 2224: ** when there is lock contention. ^If SQLite determines that invoking the busy 2225: ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2226: ** to the application instead of invoking the 2227: ** busy handler. 2228: ** Consider a scenario where one process is holding a read lock that 2229: ** it is trying to promote to a reserved lock and 2230: ** a second process is holding a reserved lock that it is trying 2231: ** to promote to an exclusive lock. The first process cannot proceed 2232: ** because it is blocked by the second and the second process cannot 2233: ** proceed because it is blocked by the first. If both processes 2234: ** invoke the busy handlers, neither will make any progress. Therefore, 2235: ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2236: ** will induce the first process to release its read lock and allow 2237: ** the second process to proceed. 2238: ** 2239: ** ^The default busy callback is NULL. 2240: ** 2241: ** ^(There can only be a single busy handler defined for each 2242: ** [database connection]. Setting a new busy handler clears any 2243: ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2244: ** or evaluating [PRAGMA busy_timeout=N] will change the 2245: ** busy handler and thus clear any previously set busy handler. 2246: ** 2247: ** The busy callback should not take any actions which modify the 2248: ** database connection that invoked the busy handler. In other words, 2249: ** the busy handler is not reentrant. Any such actions 2250: ** result in undefined behavior. 2251: ** 2252: ** A busy handler must not close the database connection 2253: ** or [prepared statement] that invoked the busy handler. 2254: */ 2255: SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2256: 2257: /* 2258: ** CAPI3REF: Set A Busy Timeout 2259: ** METHOD: sqlite3 2260: ** 2261: ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2262: ** for a specified amount of time when a table is locked. ^The handler 2263: ** will sleep multiple times until at least "ms" milliseconds of sleeping 2264: ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2265: ** the handler returns 0 which causes [sqlite3_step()] to return 2266: ** [SQLITE_BUSY]. 2267: ** 2268: ** ^Calling this routine with an argument less than or equal to zero 2269: ** turns off all busy handlers. 2270: ** 2271: ** ^(There can only be a single busy handler for a particular 2272: ** [database connection] at any given moment. If another busy handler 2273: ** was defined (using [sqlite3_busy_handler()]) prior to calling 2274: ** this routine, that other busy handler is cleared.)^ 2275: ** 2276: ** See also: [PRAGMA busy_timeout] 2277: */ 2278: SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2279: 2280: /* 2281: ** CAPI3REF: Convenience Routines For Running Queries 2282: ** METHOD: sqlite3 2283: ** 2284: ** This is a legacy interface that is preserved for backwards compatibility. 2285: ** Use of this interface is not recommended. 2286: ** 2287: ** Definition: A <b>result table</b> is memory data structure created by the 2288: ** [sqlite3_get_table()] interface. A result table records the 2289: ** complete query results from one or more queries. 2290: ** 2291: ** The table conceptually has a number of rows and columns. But 2292: ** these numbers are not part of the result table itself. These 2293: ** numbers are obtained separately. Let N be the number of rows 2294: ** and M be the number of columns. 2295: ** 2296: ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2297: ** There are (N+1)*M elements in the array. The first M pointers point 2298: ** to zero-terminated strings that contain the names of the columns. 2299: ** The remaining entries all point to query results. NULL values result 2300: ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2301: ** string representation as returned by [sqlite3_column_text()]. 2302: ** 2303: ** A result table might consist of one or more memory allocations. 2304: ** It is not safe to pass a result table directly to [sqlite3_free()]. 2305: ** A result table should be deallocated using [sqlite3_free_table()]. 2306: ** 2307: ** ^(As an example of the result table format, suppose a query result 2308: ** is as follows: 2309: ** 2310: ** <blockquote><pre> 2311: ** Name | Age 2312: ** ----------------------- 2313: ** Alice | 43 2314: ** Bob | 28 2315: ** Cindy | 21 2316: ** </pre></blockquote> 2317: ** 2318: ** There are two column (M==2) and three rows (N==3). Thus the 2319: ** result table has 8 entries. Suppose the result table is stored 2320: ** in an array names azResult. Then azResult holds this content: 2321: ** 2322: ** <blockquote><pre> 2323: ** azResult[0] = "Name"; 2324: ** azResult[1] = "Age"; 2325: ** azResult[2] = "Alice"; 2326: ** azResult[3] = "43"; 2327: ** azResult[4] = "Bob"; 2328: ** azResult[5] = "28"; 2329: ** azResult[6] = "Cindy"; 2330: ** azResult[7] = "21"; 2331: ** </pre></blockquote>)^ 2332: ** 2333: ** ^The sqlite3_get_table() function evaluates one or more 2334: ** semicolon-separated SQL statements in the zero-terminated UTF-8 2335: ** string of its 2nd parameter and returns a result table to the 2336: ** pointer given in its 3rd parameter. 2337: ** 2338: ** After the application has finished with the result from sqlite3_get_table(), 2339: ** it must pass the result table pointer to sqlite3_free_table() in order to 2340: ** release the memory that was malloced. Because of the way the 2341: ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2342: ** function must not try to call [sqlite3_free()] directly. Only 2343: ** [sqlite3_free_table()] is able to release the memory properly and safely. 2344: ** 2345: ** The sqlite3_get_table() interface is implemented as a wrapper around 2346: ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2347: ** to any internal data structures of SQLite. It uses only the public 2348: ** interface defined here. As a consequence, errors that occur in the 2349: ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2350: ** reflected in subsequent calls to [sqlite3_errcode()] or 2351: ** [sqlite3_errmsg()]. 2352: */ 2353: SQLITE_API int sqlite3_get_table( 2354: sqlite3 *db, /* An open database */ 2355: const char *zSql, /* SQL to be evaluated */ 2356: char ***pazResult, /* Results of the query */ 2357: int *pnRow, /* Number of result rows written here */ 2358: int *pnColumn, /* Number of result columns written here */ 2359: char **pzErrmsg /* Error msg written here */ 2360: ); 2361: SQLITE_API void sqlite3_free_table(char **result); 2362: 2363: /* 2364: ** CAPI3REF: Formatted String Printing Functions 2365: ** 2366: ** These routines are work-alikes of the "printf()" family of functions 2367: ** from the standard C library. 2368: ** These routines understand most of the common K&R formatting options, 2369: ** plus some additional non-standard formats, detailed below. 2370: ** Note that some of the more obscure formatting options from recent 2371: ** C-library standards are omitted from this implementation. 2372: ** 2373: ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2374: ** results into memory obtained from [sqlite3_malloc()]. 2375: ** The strings returned by these two routines should be 2376: ** released by [sqlite3_free()]. ^Both routines return a 2377: ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2378: ** memory to hold the resulting string. 2379: ** 2380: ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2381: ** the standard C library. The result is written into the 2382: ** buffer supplied as the second parameter whose size is given by 2383: ** the first parameter. Note that the order of the 2384: ** first two parameters is reversed from snprintf().)^ This is an 2385: ** historical accident that cannot be fixed without breaking 2386: ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2387: ** returns a pointer to its buffer instead of the number of 2388: ** characters actually written into the buffer.)^ We admit that 2389: ** the number of characters written would be a more useful return 2390: ** value but we cannot change the implementation of sqlite3_snprintf() 2391: ** now without breaking compatibility. 2392: ** 2393: ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2394: ** guarantees that the buffer is always zero-terminated. ^The first 2395: ** parameter "n" is the total size of the buffer, including space for 2396: ** the zero terminator. So the longest string that can be completely 2397: ** written will be n-1 characters. 2398: ** 2399: ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2400: ** 2401: ** These routines all implement some additional formatting 2402: ** options that are useful for constructing SQL statements. 2403: ** All of the usual printf() formatting options apply. In addition, there 2404: ** is are "%q", "%Q", "%w" and "%z" options. 2405: ** 2406: ** ^(The %q option works like %s in that it substitutes a nul-terminated 2407: ** string from the argument list. But %q also doubles every '\'' character. 2408: ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2409: ** character it escapes that character and allows it to be inserted into 2410: ** the string. 2411: ** 2412: ** For example, assume the string variable zText contains text as follows: 2413: ** 2414: ** <blockquote><pre> 2415: ** char *zText = "It's a happy day!"; 2416: ** </pre></blockquote> 2417: ** 2418: ** One can use this text in an SQL statement as follows: 2419: ** 2420: ** <blockquote><pre> 2421: ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2422: ** sqlite3_exec(db, zSQL, 0, 0, 0); 2423: ** sqlite3_free(zSQL); 2424: ** </pre></blockquote> 2425: ** 2426: ** Because the %q format string is used, the '\'' character in zText 2427: ** is escaped and the SQL generated is as follows: 2428: ** 2429: ** <blockquote><pre> 2430: ** INSERT INTO table1 VALUES('It''s a happy day!') 2431: ** </pre></blockquote> 2432: ** 2433: ** This is correct. Had we used %s instead of %q, the generated SQL 2434: ** would have looked like this: 2435: ** 2436: ** <blockquote><pre> 2437: ** INSERT INTO table1 VALUES('It's a happy day!'); 2438: ** </pre></blockquote> 2439: ** 2440: ** This second example is an SQL syntax error. As a general rule you should 2441: ** always use %q instead of %s when inserting text into a string literal. 2442: ** 2443: ** ^(The %Q option works like %q except it also adds single quotes around 2444: ** the outside of the total string. Additionally, if the parameter in the 2445: ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2446: ** single quotes).)^ So, for example, one could say: 2447: ** 2448: ** <blockquote><pre> 2449: ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2450: ** sqlite3_exec(db, zSQL, 0, 0, 0); 2451: ** sqlite3_free(zSQL); 2452: ** </pre></blockquote> 2453: ** 2454: ** The code above will render a correct SQL statement in the zSQL 2455: ** variable even if the zText variable is a NULL pointer. 2456: ** 2457: ** ^(The "%w" formatting option is like "%q" except that it expects to 2458: ** be contained within double-quotes instead of single quotes, and it 2459: ** escapes the double-quote character instead of the single-quote 2460: ** character.)^ The "%w" formatting option is intended for safely inserting 2461: ** table and column names into a constructed SQL statement. 2462: ** 2463: ** ^(The "%z" formatting option works like "%s" but with the 2464: ** addition that after the string has been read and copied into 2465: ** the result, [sqlite3_free()] is called on the input string.)^ 2466: */ 2467: SQLITE_API char *sqlite3_mprintf(const char*,...); 2468: SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2469: SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2470: SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2471: 2472: /* 2473: ** CAPI3REF: Memory Allocation Subsystem 2474: ** 2475: ** The SQLite core uses these three routines for all of its own 2476: ** internal memory allocation needs. "Core" in the previous sentence 2477: ** does not include operating-system specific VFS implementation. The 2478: ** Windows VFS uses native malloc() and free() for some operations. 2479: ** 2480: ** ^The sqlite3_malloc() routine returns a pointer to a block 2481: ** of memory at least N bytes in length, where N is the parameter. 2482: ** ^If sqlite3_malloc() is unable to obtain sufficient free 2483: ** memory, it returns a NULL pointer. ^If the parameter N to 2484: ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2485: ** a NULL pointer. 2486: ** 2487: ** ^The sqlite3_malloc64(N) routine works just like 2488: ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2489: ** of a signed 32-bit integer. 2490: ** 2491: ** ^Calling sqlite3_free() with a pointer previously returned 2492: ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2493: ** that it might be reused. ^The sqlite3_free() routine is 2494: ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2495: ** to sqlite3_free() is harmless. After being freed, memory 2496: ** should neither be read nor written. Even reading previously freed 2497: ** memory might result in a segmentation fault or other severe error. 2498: ** Memory corruption, a segmentation fault, or other severe error 2499: ** might result if sqlite3_free() is called with a non-NULL pointer that 2500: ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2501: ** 2502: ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2503: ** prior memory allocation X to be at least N bytes. 2504: ** ^If the X parameter to sqlite3_realloc(X,N) 2505: ** is a NULL pointer then its behavior is identical to calling 2506: ** sqlite3_malloc(N). 2507: ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2508: ** negative then the behavior is exactly the same as calling 2509: ** sqlite3_free(X). 2510: ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2511: ** of at least N bytes in size or NULL if insufficient memory is available. 2512: ** ^If M is the size of the prior allocation, then min(N,M) bytes 2513: ** of the prior allocation are copied into the beginning of buffer returned 2514: ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2515: ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2516: ** prior allocation is not freed. 2517: ** 2518: ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2519: ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2520: ** of a 32-bit signed integer. 2521: ** 2522: ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2523: ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2524: ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2525: ** ^The value returned by sqlite3_msize(X) might be larger than the number 2526: ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2527: ** sqlite3_msize(X) returns zero. If X points to something that is not 2528: ** the beginning of memory allocation, or if it points to a formerly 2529: ** valid memory allocation that has now been freed, then the behavior 2530: ** of sqlite3_msize(X) is undefined and possibly harmful. 2531: ** 2532: ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2533: ** sqlite3_malloc64(), and sqlite3_realloc64() 2534: ** is always aligned to at least an 8 byte boundary, or to a 2535: ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2536: ** option is used. 2537: ** 2538: ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2539: ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2540: ** implementation of these routines to be omitted. That capability 2541: ** is no longer provided. Only built-in memory allocators can be used. 2542: ** 2543: ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2544: ** the system malloc() and free() directly when converting 2545: ** filenames between the UTF-8 encoding used by SQLite 2546: ** and whatever filename encoding is used by the particular Windows 2547: ** installation. Memory allocation errors were detected, but 2548: ** they were reported back as [SQLITE_CANTOPEN] or 2549: ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2550: ** 2551: ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2552: ** must be either NULL or else pointers obtained from a prior 2553: ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2554: ** not yet been released. 2555: ** 2556: ** The application must not read or write any part of 2557: ** a block of memory after it has been released using 2558: ** [sqlite3_free()] or [sqlite3_realloc()]. 2559: */ 2560: SQLITE_API void *sqlite3_malloc(int); 2561: SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2562: SQLITE_API void *sqlite3_realloc(void*, int); 2563: SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2564: SQLITE_API void sqlite3_free(void*); 2565: SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2566: 2567: /* 2568: ** CAPI3REF: Memory Allocator Statistics 2569: ** 2570: ** SQLite provides these two interfaces for reporting on the status 2571: ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2572: ** routines, which form the built-in memory allocation subsystem. 2573: ** 2574: ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2575: ** of memory currently outstanding (malloced but not freed). 2576: ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2577: ** value of [sqlite3_memory_used()] since the high-water mark 2578: ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2579: ** [sqlite3_memory_highwater()] include any overhead 2580: ** added by SQLite in its implementation of [sqlite3_malloc()], 2581: ** but not overhead added by the any underlying system library 2582: ** routines that [sqlite3_malloc()] may call. 2583: ** 2584: ** ^The memory high-water mark is reset to the current value of 2585: ** [sqlite3_memory_used()] if and only if the parameter to 2586: ** [sqlite3_memory_highwater()] is true. ^The value returned 2587: ** by [sqlite3_memory_highwater(1)] is the high-water mark 2588: ** prior to the reset. 2589: */ 2590: SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2591: SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2592: 2593: /* 2594: ** CAPI3REF: Pseudo-Random Number Generator 2595: ** 2596: ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2597: ** select random [ROWID | ROWIDs] when inserting new records into a table that 2598: ** already uses the largest possible [ROWID]. The PRNG is also used for 2599: ** the build-in random() and randomblob() SQL functions. This interface allows 2600: ** applications to access the same PRNG for other purposes. 2601: ** 2602: ** ^A call to this routine stores N bytes of randomness into buffer P. 2603: ** ^The P parameter can be a NULL pointer. 2604: ** 2605: ** ^If this routine has not been previously called or if the previous 2606: ** call had N less than one or a NULL pointer for P, then the PRNG is 2607: ** seeded using randomness obtained from the xRandomness method of 2608: ** the default [sqlite3_vfs] object. 2609: ** ^If the previous call to this routine had an N of 1 or more and a 2610: ** non-NULL P then the pseudo-randomness is generated 2611: ** internally and without recourse to the [sqlite3_vfs] xRandomness 2612: ** method. 2613: */ 2614: SQLITE_API void sqlite3_randomness(int N, void *P); 2615: 2616: /* 2617: ** CAPI3REF: Compile-Time Authorization Callbacks 2618: ** METHOD: sqlite3 2619: ** 2620: ** ^This routine registers an authorizer callback with a particular 2621: ** [database connection], supplied in the first argument. 2622: ** ^The authorizer callback is invoked as SQL statements are being compiled 2623: ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2624: ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2625: ** points during the compilation process, as logic is being created 2626: ** to perform various actions, the authorizer callback is invoked to 2627: ** see if those actions are allowed. ^The authorizer callback should 2628: ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2629: ** specific action but allow the SQL statement to continue to be 2630: ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2631: ** rejected with an error. ^If the authorizer callback returns 2632: ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2633: ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2634: ** the authorizer will fail with an error message. 2635: ** 2636: ** When the callback returns [SQLITE_OK], that means the operation 2637: ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2638: ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2639: ** authorizer will fail with an error message explaining that 2640: ** access is denied. 2641: ** 2642: ** ^The first parameter to the authorizer callback is a copy of the third 2643: ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2644: ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2645: ** the particular action to be authorized. ^The third through sixth parameters 2646: ** to the callback are zero-terminated strings that contain additional 2647: ** details about the action to be authorized. 2648: ** 2649: ** ^If the action code is [SQLITE_READ] 2650: ** and the callback returns [SQLITE_IGNORE] then the 2651: ** [prepared statement] statement is constructed to substitute 2652: ** a NULL value in place of the table column that would have 2653: ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2654: ** return can be used to deny an untrusted user access to individual 2655: ** columns of a table. 2656: ** ^If the action code is [SQLITE_DELETE] and the callback returns 2657: ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2658: ** [truncate optimization] is disabled and all rows are deleted individually. 2659: ** 2660: ** An authorizer is used when [sqlite3_prepare | preparing] 2661: ** SQL statements from an untrusted source, to ensure that the SQL statements 2662: ** do not try to access data they are not allowed to see, or that they do not 2663: ** try to execute malicious statements that damage the database. For 2664: ** example, an application may allow a user to enter arbitrary 2665: ** SQL queries for evaluation by a database. But the application does 2666: ** not want the user to be able to make arbitrary changes to the 2667: ** database. An authorizer could then be put in place while the 2668: ** user-entered SQL is being [sqlite3_prepare | prepared] that 2669: ** disallows everything except [SELECT] statements. 2670: ** 2671: ** Applications that need to process SQL from untrusted sources 2672: ** might also consider lowering resource limits using [sqlite3_limit()] 2673: ** and limiting database size using the [max_page_count] [PRAGMA] 2674: ** in addition to using an authorizer. 2675: ** 2676: ** ^(Only a single authorizer can be in place on a database connection 2677: ** at a time. Each call to sqlite3_set_authorizer overrides the 2678: ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2679: ** The authorizer is disabled by default. 2680: ** 2681: ** The authorizer callback must not do anything that will modify 2682: ** the database connection that invoked the authorizer callback. 2683: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2684: ** database connections for the meaning of "modify" in this paragraph. 2685: ** 2686: ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2687: ** statement might be re-prepared during [sqlite3_step()] due to a 2688: ** schema change. Hence, the application should ensure that the 2689: ** correct authorizer callback remains in place during the [sqlite3_step()]. 2690: ** 2691: ** ^Note that the authorizer callback is invoked only during 2692: ** [sqlite3_prepare()] or its variants. Authorization is not 2693: ** performed during statement evaluation in [sqlite3_step()], unless 2694: ** as stated in the previous paragraph, sqlite3_step() invokes 2695: ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2696: */ 2697: SQLITE_API int sqlite3_set_authorizer( 2698: sqlite3*, 2699: int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2700: void *pUserData 2701: ); 2702: 2703: /* 2704: ** CAPI3REF: Authorizer Return Codes 2705: ** 2706: ** The [sqlite3_set_authorizer | authorizer callback function] must 2707: ** return either [SQLITE_OK] or one of these two constants in order 2708: ** to signal SQLite whether or not the action is permitted. See the 2709: ** [sqlite3_set_authorizer | authorizer documentation] for additional 2710: ** information. 2711: ** 2712: ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2713: ** returned from the [sqlite3_vtab_on_conflict()] interface. 2714: */ 2715: #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2716: #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2717: 2718: /* 2719: ** CAPI3REF: Authorizer Action Codes 2720: ** 2721: ** The [sqlite3_set_authorizer()] interface registers a callback function 2722: ** that is invoked to authorize certain SQL statement actions. The 2723: ** second parameter to the callback is an integer code that specifies 2724: ** what action is being authorized. These are the integer action codes that 2725: ** the authorizer callback may be passed. 2726: ** 2727: ** These action code values signify what kind of operation is to be 2728: ** authorized. The 3rd and 4th parameters to the authorization 2729: ** callback function will be parameters or NULL depending on which of these 2730: ** codes is used as the second parameter. ^(The 5th parameter to the 2731: ** authorizer callback is the name of the database ("main", "temp", 2732: ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2733: ** is the name of the inner-most trigger or view that is responsible for 2734: ** the access attempt or NULL if this access attempt is directly from 2735: ** top-level SQL code. 2736: */ 2737: /******************************************* 3rd ************ 4th ***********/ 2738: #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2739: #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2740: #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2741: #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2742: #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2743: #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2744: #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2745: #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2746: #define SQLITE_DELETE 9 /* Table Name NULL */ 2747: #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2748: #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2749: #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2750: #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2751: #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2752: #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2753: #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2754: #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2755: #define SQLITE_INSERT 18 /* Table Name NULL */ 2756: #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2757: #define SQLITE_READ 20 /* Table Name Column Name */ 2758: #define SQLITE_SELECT 21 /* NULL NULL */ 2759: #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2760: #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2761: #define SQLITE_ATTACH 24 /* Filename NULL */ 2762: #define SQLITE_DETACH 25 /* Database Name NULL */ 2763: #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2764: #define SQLITE_REINDEX 27 /* Index Name NULL */ 2765: #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2766: #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2767: #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2768: #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2769: #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2770: #define SQLITE_COPY 0 /* No longer used */ 2771: #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2772: 2773: /* 2774: ** CAPI3REF: Tracing And Profiling Functions 2775: ** METHOD: sqlite3 2776: ** 2777: ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2778: ** instead of the routines described here. 2779: ** 2780: ** These routines register callback functions that can be used for 2781: ** tracing and profiling the execution of SQL statements. 2782: ** 2783: ** ^The callback function registered by sqlite3_trace() is invoked at 2784: ** various times when an SQL statement is being run by [sqlite3_step()]. 2785: ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2786: ** SQL statement text as the statement first begins executing. 2787: ** ^(Additional sqlite3_trace() callbacks might occur 2788: ** as each triggered subprogram is entered. The callbacks for triggers 2789: ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2790: ** 2791: ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2792: ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2793: ** 2794: ** ^The callback function registered by sqlite3_profile() is invoked 2795: ** as each SQL statement finishes. ^The profile callback contains 2796: ** the original statement text and an estimate of wall-clock time 2797: ** of how long that statement took to run. ^The profile callback 2798: ** time is in units of nanoseconds, however the current implementation 2799: ** is only capable of millisecond resolution so the six least significant 2800: ** digits in the time are meaningless. Future versions of SQLite 2801: ** might provide greater resolution on the profiler callback. The 2802: ** sqlite3_profile() function is considered experimental and is 2803: ** subject to change in future versions of SQLite. 2804: */ 2805: SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2806: void(*xTrace)(void*,const char*), void*); 2807: SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2808: void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2809: 2810: /* 2811: ** CAPI3REF: SQL Trace Event Codes 2812: ** KEYWORDS: SQLITE_TRACE 2813: ** 2814: ** These constants identify classes of events that can be monitored 2815: ** using the [sqlite3_trace_v2()] tracing logic. The third argument 2816: ** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2817: ** the following constants. ^The first argument to the trace callback 2818: ** is one of the following constants. 2819: ** 2820: ** New tracing constants may be added in future releases. 2821: ** 2822: ** ^A trace callback has four arguments: xCallback(T,C,P,X). 2823: ** ^The T argument is one of the integer type codes above. 2824: ** ^The C argument is a copy of the context pointer passed in as the 2825: ** fourth argument to [sqlite3_trace_v2()]. 2826: ** The P and X arguments are pointers whose meanings depend on T. 2827: ** 2828: ** <dl> 2829: ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2830: ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2831: ** first begins running and possibly at other times during the 2832: ** execution of the prepared statement, such as at the start of each 2833: ** trigger subprogram. ^The P argument is a pointer to the 2834: ** [prepared statement]. ^The X argument is a pointer to a string which 2835: ** is the unexpanded SQL text of the prepared statement or an SQL comment 2836: ** that indicates the invocation of a trigger. ^The callback can compute 2837: ** the same text that would have been returned by the legacy [sqlite3_trace()] 2838: ** interface by using the X argument when X begins with "--" and invoking 2839: ** [sqlite3_expanded_sql(P)] otherwise. 2840: ** 2841: ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2842: ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2843: ** information as is provided by the [sqlite3_profile()] callback. 2844: ** ^The P argument is a pointer to the [prepared statement] and the 2845: ** X argument points to a 64-bit integer which is the estimated of 2846: ** the number of nanosecond that the prepared statement took to run. 2847: ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2848: ** 2849: ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2850: ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2851: ** statement generates a single row of result. 2852: ** ^The P argument is a pointer to the [prepared statement] and the 2853: ** X argument is unused. 2854: ** 2855: ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2856: ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2857: ** connection closes. 2858: ** ^The P argument is a pointer to the [database connection] object 2859: ** and the X argument is unused. 2860: ** </dl> 2861: */ 2862: #define SQLITE_TRACE_STMT 0x01 2863: #define SQLITE_TRACE_PROFILE 0x02 2864: #define SQLITE_TRACE_ROW 0x04 2865: #define SQLITE_TRACE_CLOSE 0x08 2866: 2867: /* 2868: ** CAPI3REF: SQL Trace Hook 2869: ** METHOD: sqlite3 2870: ** 2871: ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2872: ** function X against [database connection] D, using property mask M 2873: ** and context pointer P. ^If the X callback is 2874: ** NULL or if the M mask is zero, then tracing is disabled. The 2875: ** M argument should be the bitwise OR-ed combination of 2876: ** zero or more [SQLITE_TRACE] constants. 2877: ** 2878: ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2879: ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2880: ** 2881: ** ^The X callback is invoked whenever any of the events identified by 2882: ** mask M occur. ^The integer return value from the callback is currently 2883: ** ignored, though this may change in future releases. Callback 2884: ** implementations should return zero to ensure future compatibility. 2885: ** 2886: ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2887: ** ^The T argument is one of the [SQLITE_TRACE] 2888: ** constants to indicate why the callback was invoked. 2889: ** ^The C argument is a copy of the context pointer. 2890: ** The P and X arguments are pointers whose meanings depend on T. 2891: ** 2892: ** The sqlite3_trace_v2() interface is intended to replace the legacy 2893: ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 2894: ** are deprecated. 2895: */ 2896: SQLITE_API int sqlite3_trace_v2( 2897: sqlite3*, 2898: unsigned uMask, 2899: int(*xCallback)(unsigned,void*,void*,void*), 2900: void *pCtx 2901: ); 2902: 2903: /* 2904: ** CAPI3REF: Query Progress Callbacks 2905: ** METHOD: sqlite3 2906: ** 2907: ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2908: ** function X to be invoked periodically during long running calls to 2909: ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2910: ** database connection D. An example use for this 2911: ** interface is to keep a GUI updated during a large query. 2912: ** 2913: ** ^The parameter P is passed through as the only parameter to the 2914: ** callback function X. ^The parameter N is the approximate number of 2915: ** [virtual machine instructions] that are evaluated between successive 2916: ** invocations of the callback X. ^If N is less than one then the progress 2917: ** handler is disabled. 2918: ** 2919: ** ^Only a single progress handler may be defined at one time per 2920: ** [database connection]; setting a new progress handler cancels the 2921: ** old one. ^Setting parameter X to NULL disables the progress handler. 2922: ** ^The progress handler is also disabled by setting N to a value less 2923: ** than 1. 2924: ** 2925: ** ^If the progress callback returns non-zero, the operation is 2926: ** interrupted. This feature can be used to implement a 2927: ** "Cancel" button on a GUI progress dialog box. 2928: ** 2929: ** The progress handler callback must not do anything that will modify 2930: ** the database connection that invoked the progress handler. 2931: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2932: ** database connections for the meaning of "modify" in this paragraph. 2933: ** 2934: */ 2935: SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2936: 2937: /* 2938: ** CAPI3REF: Opening A New Database Connection 2939: ** CONSTRUCTOR: sqlite3 2940: ** 2941: ** ^These routines open an SQLite database file as specified by the 2942: ** filename argument. ^The filename argument is interpreted as UTF-8 for 2943: ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2944: ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2945: ** returned in *ppDb, even if an error occurs. The only exception is that 2946: ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2947: ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2948: ** object.)^ ^(If the database is opened (and/or created) successfully, then 2949: ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2950: ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2951: ** an English language description of the error following a failure of any 2952: ** of the sqlite3_open() routines. 2953: ** 2954: ** ^The default encoding will be UTF-8 for databases created using 2955: ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2956: ** created using sqlite3_open16() will be UTF-16 in the native byte order. 2957: ** 2958: ** Whether or not an error occurs when it is opened, resources 2959: ** associated with the [database connection] handle should be released by 2960: ** passing it to [sqlite3_close()] when it is no longer required. 2961: ** 2962: ** The sqlite3_open_v2() interface works like sqlite3_open() 2963: ** except that it accepts two additional parameters for additional control 2964: ** over the new database connection. ^(The flags parameter to 2965: ** sqlite3_open_v2() can take one of 2966: ** the following three values, optionally combined with the 2967: ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2968: ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2969: ** 2970: ** <dl> 2971: ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2972: ** <dd>The database is opened in read-only mode. If the database does not 2973: ** already exist, an error is returned.</dd>)^ 2974: ** 2975: ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2976: ** <dd>The database is opened for reading and writing if possible, or reading 2977: ** only if the file is write protected by the operating system. In either 2978: ** case the database must already exist, otherwise an error is returned.</dd>)^ 2979: ** 2980: ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2981: ** <dd>The database is opened for reading and writing, and is created if 2982: ** it does not already exist. This is the behavior that is always used for 2983: ** sqlite3_open() and sqlite3_open16().</dd>)^ 2984: ** </dl> 2985: ** 2986: ** If the 3rd parameter to sqlite3_open_v2() is not one of the 2987: ** combinations shown above optionally combined with other 2988: ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2989: ** then the behavior is undefined. 2990: ** 2991: ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2992: ** opens in the multi-thread [threading mode] as long as the single-thread 2993: ** mode has not been set at compile-time or start-time. ^If the 2994: ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2995: ** in the serialized [threading mode] unless single-thread was 2996: ** previously selected at compile-time or start-time. 2997: ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2998: ** eligible to use [shared cache mode], regardless of whether or not shared 2999: ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3000: ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3001: ** participate in [shared cache mode] even if it is enabled. 3002: ** 3003: ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3004: ** [sqlite3_vfs] object that defines the operating system interface that 3005: ** the new database connection should use. ^If the fourth parameter is 3006: ** a NULL pointer then the default [sqlite3_vfs] object is used. 3007: ** 3008: ** ^If the filename is ":memory:", then a private, temporary in-memory database 3009: ** is created for the connection. ^This in-memory database will vanish when 3010: ** the database connection is closed. Future versions of SQLite might 3011: ** make use of additional special filenames that begin with the ":" character. 3012: ** It is recommended that when a database filename actually does begin with 3013: ** a ":" character you should prefix the filename with a pathname such as 3014: ** "./" to avoid ambiguity. 3015: ** 3016: ** ^If the filename is an empty string, then a private, temporary 3017: ** on-disk database will be created. ^This private database will be 3018: ** automatically deleted as soon as the database connection is closed. 3019: ** 3020: ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3021: ** 3022: ** ^If [URI filename] interpretation is enabled, and the filename argument 3023: ** begins with "file:", then the filename is interpreted as a URI. ^URI 3024: ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3025: ** set in the fourth argument to sqlite3_open_v2(), or if it has 3026: ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3027: ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3028: ** As of SQLite version 3.7.7, URI filename interpretation is turned off 3029: ** by default, but future releases of SQLite might enable URI filename 3030: ** interpretation by default. See "[URI filenames]" for additional 3031: ** information. 3032: ** 3033: ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3034: ** authority, then it must be either an empty string or the string 3035: ** "localhost". ^If the authority is not an empty string or "localhost", an 3036: ** error is returned to the caller. ^The fragment component of a URI, if 3037: ** present, is ignored. 3038: ** 3039: ** ^SQLite uses the path component of the URI as the name of the disk file 3040: ** which contains the database. ^If the path begins with a '/' character, 3041: ** then it is interpreted as an absolute path. ^If the path does not begin 3042: ** with a '/' (meaning that the authority section is omitted from the URI) 3043: ** then the path is interpreted as a relative path. 3044: ** ^(On windows, the first component of an absolute path 3045: ** is a drive specification (e.g. "C:").)^ 3046: ** 3047: ** [[core URI query parameters]] 3048: ** The query component of a URI may contain parameters that are interpreted 3049: ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3050: ** SQLite and its built-in [VFSes] interpret the 3051: ** following query parameters: 3052: ** 3053: ** <ul> 3054: ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3055: ** a VFS object that provides the operating system interface that should 3056: ** be used to access the database file on disk. ^If this option is set to 3057: ** an empty string the default VFS object is used. ^Specifying an unknown 3058: ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3059: ** present, then the VFS specified by the option takes precedence over 3060: ** the value passed as the fourth parameter to sqlite3_open_v2(). 3061: ** 3062: ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3063: ** "rwc", or "memory". Attempting to set it to any other value is 3064: ** an error)^. 3065: ** ^If "ro" is specified, then the database is opened for read-only 3066: ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3067: ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3068: ** "rw", then the database is opened for read-write (but not create) 3069: ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3070: ** been set. ^Value "rwc" is equivalent to setting both 3071: ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3072: ** set to "memory" then a pure [in-memory database] that never reads 3073: ** or writes from disk is used. ^It is an error to specify a value for 3074: ** the mode parameter that is less restrictive than that specified by 3075: ** the flags passed in the third parameter to sqlite3_open_v2(). 3076: ** 3077: ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3078: ** "private". ^Setting it to "shared" is equivalent to setting the 3079: ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3080: ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3081: ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3082: ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3083: ** a URI filename, its value overrides any behavior requested by setting 3084: ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3085: ** 3086: ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3087: ** [powersafe overwrite] property does or does not apply to the 3088: ** storage media on which the database file resides. 3089: ** 3090: ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3091: ** which if set disables file locking in rollback journal modes. This 3092: ** is useful for accessing a database on a filesystem that does not 3093: ** support locking. Caution: Database corruption might result if two 3094: ** or more processes write to the same database and any one of those 3095: ** processes uses nolock=1. 3096: ** 3097: ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3098: ** parameter that indicates that the database file is stored on 3099: ** read-only media. ^When immutable is set, SQLite assumes that the 3100: ** database file cannot be changed, even by a process with higher 3101: ** privilege, and so the database is opened read-only and all locking 3102: ** and change detection is disabled. Caution: Setting the immutable 3103: ** property on a database file that does in fact change can result 3104: ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3105: ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3106: ** 3107: ** </ul> 3108: ** 3109: ** ^Specifying an unknown parameter in the query component of a URI is not an 3110: ** error. Future versions of SQLite might understand additional query 3111: ** parameters. See "[query parameters with special meaning to SQLite]" for 3112: ** additional information. 3113: ** 3114: ** [[URI filename examples]] <h3>URI filename examples</h3> 3115: ** 3116: ** <table border="1" align=center cellpadding=5> 3117: ** <tr><th> URI filenames <th> Results 3118: ** <tr><td> file:data.db <td> 3119: ** Open the file "data.db" in the current directory. 3120: ** <tr><td> file:/home/fred/data.db<br> 3121: ** file:///home/fred/data.db <br> 3122: ** file://localhost/home/fred/data.db <br> <td> 3123: ** Open the database file "/home/fred/data.db". 3124: ** <tr><td> file://darkstar/home/fred/data.db <td> 3125: ** An error. "darkstar" is not a recognized authority. 3126: ** <tr><td style="white-space:nowrap"> 3127: ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3128: ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3129: ** C:. Note that the %20 escaping in this example is not strictly 3130: ** necessary - space characters can be used literally 3131: ** in URI filenames. 3132: ** <tr><td> file:data.db?mode=ro&cache=private <td> 3133: ** Open file "data.db" in the current directory for read-only access. 3134: ** Regardless of whether or not shared-cache mode is enabled by 3135: ** default, use a private cache. 3136: ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3137: ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3138: ** that uses dot-files in place of posix advisory locking. 3139: ** <tr><td> file:data.db?mode=readonly <td> 3140: ** An error. "readonly" is not a valid option for the "mode" parameter. 3141: ** </table> 3142: ** 3143: ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3144: ** query components of a URI. A hexadecimal escape sequence consists of a 3145: ** percent sign - "%" - followed by exactly two hexadecimal digits 3146: ** specifying an octet value. ^Before the path or query components of a 3147: ** URI filename are interpreted, they are encoded using UTF-8 and all 3148: ** hexadecimal escape sequences replaced by a single byte containing the 3149: ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3150: ** the results are undefined. 3151: ** 3152: ** <b>Note to Windows users:</b> The encoding used for the filename argument 3153: ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3154: ** codepage is currently defined. Filenames containing international 3155: ** characters must be converted to UTF-8 prior to passing them into 3156: ** sqlite3_open() or sqlite3_open_v2(). 3157: ** 3158: ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3159: ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3160: ** features that require the use of temporary files may fail. 3161: ** 3162: ** See also: [sqlite3_temp_directory] 3163: */ 3164: SQLITE_API int sqlite3_open( 3165: const char *filename, /* Database filename (UTF-8) */ 3166: sqlite3 **ppDb /* OUT: SQLite db handle */ 3167: ); 3168: SQLITE_API int sqlite3_open16( 3169: const void *filename, /* Database filename (UTF-16) */ 3170: sqlite3 **ppDb /* OUT: SQLite db handle */ 3171: ); 3172: SQLITE_API int sqlite3_open_v2( 3173: const char *filename, /* Database filename (UTF-8) */ 3174: sqlite3 **ppDb, /* OUT: SQLite db handle */ 3175: int flags, /* Flags */ 3176: const char *zVfs /* Name of VFS module to use */ 3177: ); 3178: 3179: /* 3180: ** CAPI3REF: Obtain Values For URI Parameters 3181: ** 3182: ** These are utility routines, useful to VFS implementations, that check 3183: ** to see if a database file was a URI that contained a specific query 3184: ** parameter, and if so obtains the value of that query parameter. 3185: ** 3186: ** If F is the database filename pointer passed into the xOpen() method of 3187: ** a VFS implementation when the flags parameter to xOpen() has one or 3188: ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3189: ** P is the name of the query parameter, then 3190: ** sqlite3_uri_parameter(F,P) returns the value of the P 3191: ** parameter if it exists or a NULL pointer if P does not appear as a 3192: ** query parameter on F. If P is a query parameter of F 3193: ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3194: ** a pointer to an empty string. 3195: ** 3196: ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3197: ** parameter and returns true (1) or false (0) according to the value 3198: ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3199: ** value of query parameter P is one of "yes", "true", or "on" in any 3200: ** case or if the value begins with a non-zero number. The 3201: ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3202: ** query parameter P is one of "no", "false", or "off" in any case or 3203: ** if the value begins with a numeric zero. If P is not a query 3204: ** parameter on F or if the value of P is does not match any of the 3205: ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3206: ** 3207: ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3208: ** 64-bit signed integer and returns that integer, or D if P does not 3209: ** exist. If the value of P is something other than an integer, then 3210: ** zero is returned. 3211: ** 3212: ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3213: ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3214: ** is not a database file pathname pointer that SQLite passed into the xOpen 3215: ** VFS method, then the behavior of this routine is undefined and probably 3216: ** undesirable. 3217: */ 3218: SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3219: SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3220: SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3221: 3222: 3223: /* 3224: ** CAPI3REF: Error Codes And Messages 3225: ** METHOD: sqlite3 3226: ** 3227: ** ^If the most recent sqlite3_* API call associated with 3228: ** [database connection] D failed, then the sqlite3_errcode(D) interface 3229: ** returns the numeric [result code] or [extended result code] for that 3230: ** API call. 3231: ** If the most recent API call was successful, 3232: ** then the return value from sqlite3_errcode() is undefined. 3233: ** ^The sqlite3_extended_errcode() 3234: ** interface is the same except that it always returns the 3235: ** [extended result code] even when extended result codes are 3236: ** disabled. 3237: ** 3238: ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3239: ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3240: ** ^(Memory to hold the error message string is managed internally. 3241: ** The application does not need to worry about freeing the result. 3242: ** However, the error string might be overwritten or deallocated by 3243: ** subsequent calls to other SQLite interface functions.)^ 3244: ** 3245: ** ^The sqlite3_errstr() interface returns the English-language text 3246: ** that describes the [result code], as UTF-8. 3247: ** ^(Memory to hold the error message string is managed internally 3248: ** and must not be freed by the application)^. 3249: ** 3250: ** When the serialized [threading mode] is in use, it might be the 3251: ** case that a second error occurs on a separate thread in between 3252: ** the time of the first error and the call to these interfaces. 3253: ** When that happens, the second error will be reported since these 3254: ** interfaces always report the most recent result. To avoid 3255: ** this, each thread can obtain exclusive use of the [database connection] D 3256: ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3257: ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3258: ** all calls to the interfaces listed here are completed. 3259: ** 3260: ** If an interface fails with SQLITE_MISUSE, that means the interface 3261: ** was invoked incorrectly by the application. In that case, the 3262: ** error code and message may or may not be set. 3263: */ 3264: SQLITE_API int sqlite3_errcode(sqlite3 *db); 3265: SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3266: SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3267: SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3268: SQLITE_API const char *sqlite3_errstr(int); 3269: 3270: /* 3271: ** CAPI3REF: Prepared Statement Object 3272: ** KEYWORDS: {prepared statement} {prepared statements} 3273: ** 3274: ** An instance of this object represents a single SQL statement that 3275: ** has been compiled into binary form and is ready to be evaluated. 3276: ** 3277: ** Think of each SQL statement as a separate computer program. The 3278: ** original SQL text is source code. A prepared statement object 3279: ** is the compiled object code. All SQL must be converted into a 3280: ** prepared statement before it can be run. 3281: ** 3282: ** The life-cycle of a prepared statement object usually goes like this: 3283: ** 3284: ** <ol> 3285: ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3286: ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3287: ** interfaces. 3288: ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3289: ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3290: ** to step 2. Do this zero or more times. 3291: ** <li> Destroy the object using [sqlite3_finalize()]. 3292: ** </ol> 3293: */ 3294: typedef struct sqlite3_stmt sqlite3_stmt; 3295: 3296: /* 3297: ** CAPI3REF: Run-time Limits 3298: ** METHOD: sqlite3 3299: ** 3300: ** ^(This interface allows the size of various constructs to be limited 3301: ** on a connection by connection basis. The first parameter is the 3302: ** [database connection] whose limit is to be set or queried. The 3303: ** second parameter is one of the [limit categories] that define a 3304: ** class of constructs to be size limited. The third parameter is the 3305: ** new limit for that construct.)^ 3306: ** 3307: ** ^If the new limit is a negative number, the limit is unchanged. 3308: ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3309: ** [limits | hard upper bound] 3310: ** set at compile-time by a C preprocessor macro called 3311: ** [limits | SQLITE_MAX_<i>NAME</i>]. 3312: ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3313: ** ^Attempts to increase a limit above its hard upper bound are 3314: ** silently truncated to the hard upper bound. 3315: ** 3316: ** ^Regardless of whether or not the limit was changed, the 3317: ** [sqlite3_limit()] interface returns the prior value of the limit. 3318: ** ^Hence, to find the current value of a limit without changing it, 3319: ** simply invoke this interface with the third parameter set to -1. 3320: ** 3321: ** Run-time limits are intended for use in applications that manage 3322: ** both their own internal database and also databases that are controlled 3323: ** by untrusted external sources. An example application might be a 3324: ** web browser that has its own databases for storing history and 3325: ** separate databases controlled by JavaScript applications downloaded 3326: ** off the Internet. The internal databases can be given the 3327: ** large, default limits. Databases managed by external sources can 3328: ** be given much smaller limits designed to prevent a denial of service 3329: ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3330: ** interface to further control untrusted SQL. The size of the database 3331: ** created by an untrusted script can be contained using the 3332: ** [max_page_count] [PRAGMA]. 3333: ** 3334: ** New run-time limit categories may be added in future releases. 3335: */ 3336: SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3337: 3338: /* 3339: ** CAPI3REF: Run-Time Limit Categories 3340: ** KEYWORDS: {limit category} {*limit categories} 3341: ** 3342: ** These constants define various performance limits 3343: ** that can be lowered at run-time using [sqlite3_limit()]. 3344: ** The synopsis of the meanings of the various limits is shown below. 3345: ** Additional information is available at [limits | Limits in SQLite]. 3346: ** 3347: ** <dl> 3348: ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3349: ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3350: ** 3351: ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3352: ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3353: ** 3354: ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3355: ** <dd>The maximum number of columns in a table definition or in the 3356: ** result set of a [SELECT] or the maximum number of columns in an index 3357: ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3358: ** 3359: ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3360: ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3361: ** 3362: ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3363: ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3364: ** 3365: ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3366: ** <dd>The maximum number of instructions in a virtual machine program 3367: ** used to implement an SQL statement. This limit is not currently 3368: ** enforced, though that might be added in some future release of 3369: ** SQLite.</dd>)^ 3370: ** 3371: ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3372: ** <dd>The maximum number of arguments on a function.</dd>)^ 3373: ** 3374: ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3375: ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3376: ** 3377: ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3378: ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3379: ** <dd>The maximum length of the pattern argument to the [LIKE] or 3380: ** [GLOB] operators.</dd>)^ 3381: ** 3382: ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3383: ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3384: ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3385: ** 3386: ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3387: ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3388: ** 3389: ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3390: ** <dd>The maximum number of auxiliary worker threads that a single 3391: ** [prepared statement] may start.</dd>)^ 3392: ** </dl> 3393: */ 3394: #define SQLITE_LIMIT_LENGTH 0 3395: #define SQLITE_LIMIT_SQL_LENGTH 1 3396: #define SQLITE_LIMIT_COLUMN 2 3397: #define SQLITE_LIMIT_EXPR_DEPTH 3 3398: #define SQLITE_LIMIT_COMPOUND_SELECT 4 3399: #define SQLITE_LIMIT_VDBE_OP 5 3400: #define SQLITE_LIMIT_FUNCTION_ARG 6 3401: #define SQLITE_LIMIT_ATTACHED 7 3402: #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3403: #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3404: #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3405: #define SQLITE_LIMIT_WORKER_THREADS 11 3406: 3407: /* 3408: ** CAPI3REF: Compiling An SQL Statement 3409: ** KEYWORDS: {SQL statement compiler} 3410: ** METHOD: sqlite3 3411: ** CONSTRUCTOR: sqlite3_stmt 3412: ** 3413: ** To execute an SQL query, it must first be compiled into a byte-code 3414: ** program using one of these routines. 3415: ** 3416: ** The first argument, "db", is a [database connection] obtained from a 3417: ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3418: ** [sqlite3_open16()]. The database connection must not have been closed. 3419: ** 3420: ** The second argument, "zSql", is the statement to be compiled, encoded 3421: ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3422: ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3423: ** use UTF-16. 3424: ** 3425: ** ^If the nByte argument is negative, then zSql is read up to the 3426: ** first zero terminator. ^If nByte is positive, then it is the 3427: ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3428: ** statement is generated. 3429: ** If the caller knows that the supplied string is nul-terminated, then 3430: ** there is a small performance advantage to passing an nByte parameter that 3431: ** is the number of bytes in the input string <i>including</i> 3432: ** the nul-terminator. 3433: ** 3434: ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3435: ** past the end of the first SQL statement in zSql. These routines only 3436: ** compile the first statement in zSql, so *pzTail is left pointing to 3437: ** what remains uncompiled. 3438: ** 3439: ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3440: ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3441: ** to NULL. ^If the input text contains no SQL (if the input is an empty 3442: ** string or a comment) then *ppStmt is set to NULL. 3443: ** The calling procedure is responsible for deleting the compiled 3444: ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3445: ** ppStmt may not be NULL. 3446: ** 3447: ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3448: ** otherwise an [error code] is returned. 3449: ** 3450: ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3451: ** recommended for all new programs. The two older interfaces are retained 3452: ** for backwards compatibility, but their use is discouraged. 3453: ** ^In the "v2" interfaces, the prepared statement 3454: ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3455: ** original SQL text. This causes the [sqlite3_step()] interface to 3456: ** behave differently in three ways: 3457: ** 3458: ** <ol> 3459: ** <li> 3460: ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3461: ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3462: ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3463: ** retries will occur before sqlite3_step() gives up and returns an error. 3464: ** </li> 3465: ** 3466: ** <li> 3467: ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3468: ** [error codes] or [extended error codes]. ^The legacy behavior was that 3469: ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3470: ** and the application would have to make a second call to [sqlite3_reset()] 3471: ** in order to find the underlying cause of the problem. With the "v2" prepare 3472: ** interfaces, the underlying reason for the error is returned immediately. 3473: ** </li> 3474: ** 3475: ** <li> 3476: ** ^If the specific value bound to [parameter | host parameter] in the 3477: ** WHERE clause might influence the choice of query plan for a statement, 3478: ** then the statement will be automatically recompiled, as if there had been 3479: ** a schema change, on the first [sqlite3_step()] call following any change 3480: ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3481: ** ^The specific value of WHERE-clause [parameter] might influence the 3482: ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3483: ** or [GLOB] operator or if the parameter is compared to an indexed column 3484: ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3485: ** </li> 3486: ** </ol> 3487: */ 3488: SQLITE_API int sqlite3_prepare( 3489: sqlite3 *db, /* Database handle */ 3490: const char *zSql, /* SQL statement, UTF-8 encoded */ 3491: int nByte, /* Maximum length of zSql in bytes. */ 3492: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3493: const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3494: ); 3495: SQLITE_API int sqlite3_prepare_v2( 3496: sqlite3 *db, /* Database handle */ 3497: const char *zSql, /* SQL statement, UTF-8 encoded */ 3498: int nByte, /* Maximum length of zSql in bytes. */ 3499: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3500: const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3501: ); 3502: SQLITE_API int sqlite3_prepare16( 3503: sqlite3 *db, /* Database handle */ 3504: const void *zSql, /* SQL statement, UTF-16 encoded */ 3505: int nByte, /* Maximum length of zSql in bytes. */ 3506: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3507: const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3508: ); 3509: SQLITE_API int sqlite3_prepare16_v2( 3510: sqlite3 *db, /* Database handle */ 3511: const void *zSql, /* SQL statement, UTF-16 encoded */ 3512: int nByte, /* Maximum length of zSql in bytes. */ 3513: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3514: const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3515: ); 3516: 3517: /* 3518: ** CAPI3REF: Retrieving Statement SQL 3519: ** METHOD: sqlite3_stmt 3520: ** 3521: ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3522: ** SQL text used to create [prepared statement] P if P was 3523: ** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3524: ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3525: ** string containing the SQL text of prepared statement P with 3526: ** [bound parameters] expanded. 3527: ** 3528: ** ^(For example, if a prepared statement is created using the SQL 3529: ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3530: ** and parameter :xyz is unbound, then sqlite3_sql() will return 3531: ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3532: ** will return "SELECT 2345,NULL".)^ 3533: ** 3534: ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3535: ** is available to hold the result, or if the result would exceed the 3536: ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3537: ** 3538: ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3539: ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3540: ** option causes sqlite3_expanded_sql() to always return NULL. 3541: ** 3542: ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3543: ** automatically freed when the prepared statement is finalized. 3544: ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3545: ** is obtained from [sqlite3_malloc()] and must be free by the application 3546: ** by passing it to [sqlite3_free()]. 3547: */ 3548: SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3549: SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3550: 3551: /* 3552: ** CAPI3REF: Determine If An SQL Statement Writes The Database 3553: ** METHOD: sqlite3_stmt 3554: ** 3555: ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3556: ** and only if the [prepared statement] X makes no direct changes to 3557: ** the content of the database file. 3558: ** 3559: ** Note that [application-defined SQL functions] or 3560: ** [virtual tables] might change the database indirectly as a side effect. 3561: ** ^(For example, if an application defines a function "eval()" that 3562: ** calls [sqlite3_exec()], then the following SQL statement would 3563: ** change the database file through side-effects: 3564: ** 3565: ** <blockquote><pre> 3566: ** SELECT eval('DELETE FROM t1') FROM t2; 3567: ** </pre></blockquote> 3568: ** 3569: ** But because the [SELECT] statement does not change the database file 3570: ** directly, sqlite3_stmt_readonly() would still return true.)^ 3571: ** 3572: ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3573: ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3574: ** since the statements themselves do not actually modify the database but 3575: ** rather they control the timing of when other statements modify the 3576: ** database. ^The [ATTACH] and [DETACH] statements also cause 3577: ** sqlite3_stmt_readonly() to return true since, while those statements 3578: ** change the configuration of a database connection, they do not make 3579: ** changes to the content of the database files on disk. 3580: */ 3581: SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3582: 3583: /* 3584: ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3585: ** METHOD: sqlite3_stmt 3586: ** 3587: ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3588: ** [prepared statement] S has been stepped at least once using 3589: ** [sqlite3_step(S)] but has neither run to completion (returned 3590: ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3591: ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3592: ** interface returns false if S is a NULL pointer. If S is not a 3593: ** NULL pointer and is not a pointer to a valid [prepared statement] 3594: ** object, then the behavior is undefined and probably undesirable. 3595: ** 3596: ** This interface can be used in combination [sqlite3_next_stmt()] 3597: ** to locate all prepared statements associated with a database 3598: ** connection that are in need of being reset. This can be used, 3599: ** for example, in diagnostic routines to search for prepared 3600: ** statements that are holding a transaction open. 3601: */ 3602: SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3603: 3604: /* 3605: ** CAPI3REF: Dynamically Typed Value Object 3606: ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3607: ** 3608: ** SQLite uses the sqlite3_value object to represent all values 3609: ** that can be stored in a database table. SQLite uses dynamic typing 3610: ** for the values it stores. ^Values stored in sqlite3_value objects 3611: ** can be integers, floating point values, strings, BLOBs, or NULL. 3612: ** 3613: ** An sqlite3_value object may be either "protected" or "unprotected". 3614: ** Some interfaces require a protected sqlite3_value. Other interfaces 3615: ** will accept either a protected or an unprotected sqlite3_value. 3616: ** Every interface that accepts sqlite3_value arguments specifies 3617: ** whether or not it requires a protected sqlite3_value. The 3618: ** [sqlite3_value_dup()] interface can be used to construct a new 3619: ** protected sqlite3_value from an unprotected sqlite3_value. 3620: ** 3621: ** The terms "protected" and "unprotected" refer to whether or not 3622: ** a mutex is held. An internal mutex is held for a protected 3623: ** sqlite3_value object but no mutex is held for an unprotected 3624: ** sqlite3_value object. If SQLite is compiled to be single-threaded 3625: ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3626: ** or if SQLite is run in one of reduced mutex modes 3627: ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3628: ** then there is no distinction between protected and unprotected 3629: ** sqlite3_value objects and they can be used interchangeably. However, 3630: ** for maximum code portability it is recommended that applications 3631: ** still make the distinction between protected and unprotected 3632: ** sqlite3_value objects even when not strictly required. 3633: ** 3634: ** ^The sqlite3_value objects that are passed as parameters into the 3635: ** implementation of [application-defined SQL functions] are protected. 3636: ** ^The sqlite3_value object returned by 3637: ** [sqlite3_column_value()] is unprotected. 3638: ** Unprotected sqlite3_value objects may only be used with 3639: ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3640: ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3641: ** interfaces require protected sqlite3_value objects. 3642: */ 3643: typedef struct Mem sqlite3_value; 3644: 3645: /* 3646: ** CAPI3REF: SQL Function Context Object 3647: ** 3648: ** The context in which an SQL function executes is stored in an 3649: ** sqlite3_context object. ^A pointer to an sqlite3_context object 3650: ** is always first parameter to [application-defined SQL functions]. 3651: ** The application-defined SQL function implementation will pass this 3652: ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3653: ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3654: ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3655: ** and/or [sqlite3_set_auxdata()]. 3656: */ 3657: typedef struct sqlite3_context sqlite3_context; 3658: 3659: /* 3660: ** CAPI3REF: Binding Values To Prepared Statements 3661: ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3662: ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3663: ** METHOD: sqlite3_stmt 3664: ** 3665: ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3666: ** literals may be replaced by a [parameter] that matches one of following 3667: ** templates: 3668: ** 3669: ** <ul> 3670: ** <li> ? 3671: ** <li> ?NNN 3672: ** <li> :VVV 3673: ** <li> @VVV 3674: ** <li> $VVV 3675: ** </ul> 3676: ** 3677: ** In the templates above, NNN represents an integer literal, 3678: ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3679: ** parameters (also called "host parameter names" or "SQL parameters") 3680: ** can be set using the sqlite3_bind_*() routines defined here. 3681: ** 3682: ** ^The first argument to the sqlite3_bind_*() routines is always 3683: ** a pointer to the [sqlite3_stmt] object returned from 3684: ** [sqlite3_prepare_v2()] or its variants. 3685: ** 3686: ** ^The second argument is the index of the SQL parameter to be set. 3687: ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3688: ** SQL parameter is used more than once, second and subsequent 3689: ** occurrences have the same index as the first occurrence. 3690: ** ^The index for named parameters can be looked up using the 3691: ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3692: ** for "?NNN" parameters is the value of NNN. 3693: ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3694: ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3695: ** 3696: ** ^The third argument is the value to bind to the parameter. 3697: ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3698: ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3699: ** is ignored and the end result is the same as sqlite3_bind_null(). 3700: ** 3701: ** ^(In those routines that have a fourth argument, its value is the 3702: ** number of bytes in the parameter. To be clear: the value is the 3703: ** number of <u>bytes</u> in the value, not the number of characters.)^ 3704: ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3705: ** is negative, then the length of the string is 3706: ** the number of bytes up to the first zero terminator. 3707: ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3708: ** the behavior is undefined. 3709: ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3710: ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3711: ** that parameter must be the byte offset 3712: ** where the NUL terminator would occur assuming the string were NUL 3713: ** terminated. If any NUL characters occur at byte offsets less than 3714: ** the value of the fourth parameter then the resulting string value will 3715: ** contain embedded NULs. The result of expressions involving strings 3716: ** with embedded NULs is undefined. 3717: ** 3718: ** ^The fifth argument to the BLOB and string binding interfaces 3719: ** is a destructor used to dispose of the BLOB or 3720: ** string after SQLite has finished with it. ^The destructor is called 3721: ** to dispose of the BLOB or string even if the call to bind API fails. 3722: ** ^If the fifth argument is 3723: ** the special value [SQLITE_STATIC], then SQLite assumes that the 3724: ** information is in static, unmanaged space and does not need to be freed. 3725: ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3726: ** SQLite makes its own private copy of the data immediately, before 3727: ** the sqlite3_bind_*() routine returns. 3728: ** 3729: ** ^The sixth argument to sqlite3_bind_text64() must be one of 3730: ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3731: ** to specify the encoding of the text in the third parameter. If 3732: ** the sixth argument to sqlite3_bind_text64() is not one of the 3733: ** allowed values shown above, or if the text encoding is different 3734: ** from the encoding specified by the sixth parameter, then the behavior 3735: ** is undefined. 3736: ** 3737: ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3738: ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3739: ** (just an integer to hold its size) while it is being processed. 3740: ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3741: ** content is later written using 3742: ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3743: ** ^A negative value for the zeroblob results in a zero-length BLOB. 3744: ** 3745: ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3746: ** for the [prepared statement] or with a prepared statement for which 3747: ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3748: ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3749: ** routine is passed a [prepared statement] that has been finalized, the 3750: ** result is undefined and probably harmful. 3751: ** 3752: ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3753: ** ^Unbound parameters are interpreted as NULL. 3754: ** 3755: ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3756: ** [error code] if anything goes wrong. 3757: ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3758: ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3759: ** [SQLITE_MAX_LENGTH]. 3760: ** ^[SQLITE_RANGE] is returned if the parameter 3761: ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3762: ** 3763: ** See also: [sqlite3_bind_parameter_count()], 3764: ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3765: */ 3766: SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3767: SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3768: void(*)(void*)); 3769: SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3770: SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3771: SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3772: SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3773: SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3774: SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3775: SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3776: void(*)(void*), unsigned char encoding); 3777: SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3778: SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3779: SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3780: 3781: /* 3782: ** CAPI3REF: Number Of SQL Parameters 3783: ** METHOD: sqlite3_stmt 3784: ** 3785: ** ^This routine can be used to find the number of [SQL parameters] 3786: ** in a [prepared statement]. SQL parameters are tokens of the 3787: ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3788: ** placeholders for values that are [sqlite3_bind_blob | bound] 3789: ** to the parameters at a later time. 3790: ** 3791: ** ^(This routine actually returns the index of the largest (rightmost) 3792: ** parameter. For all forms except ?NNN, this will correspond to the 3793: ** number of unique parameters. If parameters of the ?NNN form are used, 3794: ** there may be gaps in the list.)^ 3795: ** 3796: ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3797: ** [sqlite3_bind_parameter_name()], and 3798: ** [sqlite3_bind_parameter_index()]. 3799: */ 3800: SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3801: 3802: /* 3803: ** CAPI3REF: Name Of A Host Parameter 3804: ** METHOD: sqlite3_stmt 3805: ** 3806: ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3807: ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3808: ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3809: ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3810: ** respectively. 3811: ** In other words, the initial ":" or "$" or "@" or "?" 3812: ** is included as part of the name.)^ 3813: ** ^Parameters of the form "?" without a following integer have no name 3814: ** and are referred to as "nameless" or "anonymous parameters". 3815: ** 3816: ** ^The first host parameter has an index of 1, not 0. 3817: ** 3818: ** ^If the value N is out of range or if the N-th parameter is 3819: ** nameless, then NULL is returned. ^The returned string is 3820: ** always in UTF-8 encoding even if the named parameter was 3821: ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3822: ** [sqlite3_prepare16_v2()]. 3823: ** 3824: ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3825: ** [sqlite3_bind_parameter_count()], and 3826: ** [sqlite3_bind_parameter_index()]. 3827: */ 3828: SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3829: 3830: /* 3831: ** CAPI3REF: Index Of A Parameter With A Given Name 3832: ** METHOD: sqlite3_stmt 3833: ** 3834: ** ^Return the index of an SQL parameter given its name. ^The 3835: ** index value returned is suitable for use as the second 3836: ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3837: ** is returned if no matching parameter is found. ^The parameter 3838: ** name must be given in UTF-8 even if the original statement 3839: ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3840: ** 3841: ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3842: ** [sqlite3_bind_parameter_count()], and 3843: ** [sqlite3_bind_parameter_name()]. 3844: */ 3845: SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3846: 3847: /* 3848: ** CAPI3REF: Reset All Bindings On A Prepared Statement 3849: ** METHOD: sqlite3_stmt 3850: ** 3851: ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3852: ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3853: ** ^Use this routine to reset all host parameters to NULL. 3854: */ 3855: SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3856: 3857: /* 3858: ** CAPI3REF: Number Of Columns In A Result Set 3859: ** METHOD: sqlite3_stmt 3860: ** 3861: ** ^Return the number of columns in the result set returned by the 3862: ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3863: ** statement that does not return data (for example an [UPDATE]). 3864: ** 3865: ** See also: [sqlite3_data_count()] 3866: */ 3867: SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3868: 3869: /* 3870: ** CAPI3REF: Column Names In A Result Set 3871: ** METHOD: sqlite3_stmt 3872: ** 3873: ** ^These routines return the name assigned to a particular column 3874: ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3875: ** interface returns a pointer to a zero-terminated UTF-8 string 3876: ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3877: ** UTF-16 string. ^The first parameter is the [prepared statement] 3878: ** that implements the [SELECT] statement. ^The second parameter is the 3879: ** column number. ^The leftmost column is number 0. 3880: ** 3881: ** ^The returned string pointer is valid until either the [prepared statement] 3882: ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3883: ** reprepared by the first call to [sqlite3_step()] for a particular run 3884: ** or until the next call to 3885: ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3886: ** 3887: ** ^If sqlite3_malloc() fails during the processing of either routine 3888: ** (for example during a conversion from UTF-8 to UTF-16) then a 3889: ** NULL pointer is returned. 3890: ** 3891: ** ^The name of a result column is the value of the "AS" clause for 3892: ** that column, if there is an AS clause. If there is no AS clause 3893: ** then the name of the column is unspecified and may change from 3894: ** one release of SQLite to the next. 3895: */ 3896: SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 3897: SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3898: 3899: /* 3900: ** CAPI3REF: Source Of Data In A Query Result 3901: ** METHOD: sqlite3_stmt 3902: ** 3903: ** ^These routines provide a means to determine the database, table, and 3904: ** table column that is the origin of a particular result column in 3905: ** [SELECT] statement. 3906: ** ^The name of the database or table or column can be returned as 3907: ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3908: ** the database name, the _table_ routines return the table name, and 3909: ** the origin_ routines return the column name. 3910: ** ^The returned string is valid until the [prepared statement] is destroyed 3911: ** using [sqlite3_finalize()] or until the statement is automatically 3912: ** reprepared by the first call to [sqlite3_step()] for a particular run 3913: ** or until the same information is requested 3914: ** again in a different encoding. 3915: ** 3916: ** ^The names returned are the original un-aliased names of the 3917: ** database, table, and column. 3918: ** 3919: ** ^The first argument to these interfaces is a [prepared statement]. 3920: ** ^These functions return information about the Nth result column returned by 3921: ** the statement, where N is the second function argument. 3922: ** ^The left-most column is column 0 for these routines. 3923: ** 3924: ** ^If the Nth column returned by the statement is an expression or 3925: ** subquery and is not a column value, then all of these functions return 3926: ** NULL. ^These routine might also return NULL if a memory allocation error 3927: ** occurs. ^Otherwise, they return the name of the attached database, table, 3928: ** or column that query result column was extracted from. 3929: ** 3930: ** ^As with all other SQLite APIs, those whose names end with "16" return 3931: ** UTF-16 encoded strings and the other functions return UTF-8. 3932: ** 3933: ** ^These APIs are only available if the library was compiled with the 3934: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3935: ** 3936: ** If two or more threads call one or more of these routines against the same 3937: ** prepared statement and column at the same time then the results are 3938: ** undefined. 3939: ** 3940: ** If two or more threads call one or more 3941: ** [sqlite3_column_database_name | column metadata interfaces] 3942: ** for the same [prepared statement] and result column 3943: ** at the same time then the results are undefined. 3944: */ 3945: SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3946: SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3947: SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3948: SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3949: SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3950: SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3951: 3952: /* 3953: ** CAPI3REF: Declared Datatype Of A Query Result 3954: ** METHOD: sqlite3_stmt 3955: ** 3956: ** ^(The first parameter is a [prepared statement]. 3957: ** If this statement is a [SELECT] statement and the Nth column of the 3958: ** returned result set of that [SELECT] is a table column (not an 3959: ** expression or subquery) then the declared type of the table 3960: ** column is returned.)^ ^If the Nth column of the result set is an 3961: ** expression or subquery, then a NULL pointer is returned. 3962: ** ^The returned string is always UTF-8 encoded. 3963: ** 3964: ** ^(For example, given the database schema: 3965: ** 3966: ** CREATE TABLE t1(c1 VARIANT); 3967: ** 3968: ** and the following statement to be compiled: 3969: ** 3970: ** SELECT c1 + 1, c1 FROM t1; 3971: ** 3972: ** this routine would return the string "VARIANT" for the second result 3973: ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3974: ** 3975: ** ^SQLite uses dynamic run-time typing. ^So just because a column 3976: ** is declared to contain a particular type does not mean that the 3977: ** data stored in that column is of the declared type. SQLite is 3978: ** strongly typed, but the typing is dynamic not static. ^Type 3979: ** is associated with individual values, not with the containers 3980: ** used to hold those values. 3981: */ 3982: SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3983: SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3984: 3985: /* 3986: ** CAPI3REF: Evaluate An SQL Statement 3987: ** METHOD: sqlite3_stmt 3988: ** 3989: ** After a [prepared statement] has been prepared using either 3990: ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3991: ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3992: ** must be called one or more times to evaluate the statement. 3993: ** 3994: ** The details of the behavior of the sqlite3_step() interface depend 3995: ** on whether the statement was prepared using the newer "v2" interface 3996: ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3997: ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3998: ** new "v2" interface is recommended for new applications but the legacy 3999: ** interface will continue to be supported. 4000: ** 4001: ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4002: ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4003: ** ^With the "v2" interface, any of the other [result codes] or 4004: ** [extended result codes] might be returned as well. 4005: ** 4006: ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4007: ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4008: ** or occurs outside of an explicit transaction, then you can retry the 4009: ** statement. If the statement is not a [COMMIT] and occurs within an 4010: ** explicit transaction then you should rollback the transaction before 4011: ** continuing. 4012: ** 4013: ** ^[SQLITE_DONE] means that the statement has finished executing 4014: ** successfully. sqlite3_step() should not be called again on this virtual 4015: ** machine without first calling [sqlite3_reset()] to reset the virtual 4016: ** machine back to its initial state. 4017: ** 4018: ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4019: ** is returned each time a new row of data is ready for processing by the 4020: ** caller. The values may be accessed using the [column access functions]. 4021: ** sqlite3_step() is called again to retrieve the next row of data. 4022: ** 4023: ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4024: ** violation) has occurred. sqlite3_step() should not be called again on 4025: ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4026: ** ^With the legacy interface, a more specific error code (for example, 4027: ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4028: ** can be obtained by calling [sqlite3_reset()] on the 4029: ** [prepared statement]. ^In the "v2" interface, 4030: ** the more specific error code is returned directly by sqlite3_step(). 4031: ** 4032: ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4033: ** Perhaps it was called on a [prepared statement] that has 4034: ** already been [sqlite3_finalize | finalized] or on one that had 4035: ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4036: ** be the case that the same database connection is being used by two or 4037: ** more threads at the same moment in time. 4038: ** 4039: ** For all versions of SQLite up to and including 3.6.23.1, a call to 4040: ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4041: ** other than [SQLITE_ROW] before any subsequent invocation of 4042: ** sqlite3_step(). Failure to reset the prepared statement using 4043: ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4044: ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 4045: ** calling [sqlite3_reset()] automatically in this circumstance rather 4046: ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4047: ** break because any application that ever receives an SQLITE_MISUSE error 4048: ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4049: ** can be used to restore the legacy behavior. 4050: ** 4051: ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4052: ** API always returns a generic error code, [SQLITE_ERROR], following any 4053: ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4054: ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4055: ** specific [error codes] that better describes the error. 4056: ** We admit that this is a goofy design. The problem has been fixed 4057: ** with the "v2" interface. If you prepare all of your SQL statements 4058: ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 4059: ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4060: ** then the more specific [error codes] are returned directly 4061: ** by sqlite3_step(). The use of the "v2" interface is recommended. 4062: */ 4063: SQLITE_API int sqlite3_step(sqlite3_stmt*); 4064: 4065: /* 4066: ** CAPI3REF: Number of columns in a result set 4067: ** METHOD: sqlite3_stmt 4068: ** 4069: ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4070: ** current row of the result set of [prepared statement] P. 4071: ** ^If prepared statement P does not have results ready to return 4072: ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4073: ** interfaces) then sqlite3_data_count(P) returns 0. 4074: ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4075: ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4076: ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4077: ** will return non-zero if previous call to [sqlite3_step](P) returned 4078: ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4079: ** where it always returns zero since each step of that multi-step 4080: ** pragma returns 0 columns of data. 4081: ** 4082: ** See also: [sqlite3_column_count()] 4083: */ 4084: SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4085: 4086: /* 4087: ** CAPI3REF: Fundamental Datatypes 4088: ** KEYWORDS: SQLITE_TEXT 4089: ** 4090: ** ^(Every value in SQLite has one of five fundamental datatypes: 4091: ** 4092: ** <ul> 4093: ** <li> 64-bit signed integer 4094: ** <li> 64-bit IEEE floating point number 4095: ** <li> string 4096: ** <li> BLOB 4097: ** <li> NULL 4098: ** </ul>)^ 4099: ** 4100: ** These constants are codes for each of those types. 4101: ** 4102: ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4103: ** for a completely different meaning. Software that links against both 4104: ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4105: ** SQLITE_TEXT. 4106: */ 4107: #define SQLITE_INTEGER 1 4108: #define SQLITE_FLOAT 2 4109: #define SQLITE_BLOB 4 4110: #define SQLITE_NULL 5 4111: #ifdef SQLITE_TEXT 4112: # undef SQLITE_TEXT 4113: #else 4114: # define SQLITE_TEXT 3 4115: #endif 4116: #define SQLITE3_TEXT 3 4117: 4118: /* 4119: ** CAPI3REF: Result Values From A Query 4120: ** KEYWORDS: {column access functions} 4121: ** METHOD: sqlite3_stmt 4122: ** 4123: ** ^These routines return information about a single column of the current 4124: ** result row of a query. ^In every case the first argument is a pointer 4125: ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4126: ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4127: ** and the second argument is the index of the column for which information 4128: ** should be returned. ^The leftmost column of the result set has the index 0. 4129: ** ^The number of columns in the result can be determined using 4130: ** [sqlite3_column_count()]. 4131: ** 4132: ** If the SQL statement does not currently point to a valid row, or if the 4133: ** column index is out of range, the result is undefined. 4134: ** These routines may only be called when the most recent call to 4135: ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4136: ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4137: ** If any of these routines are called after [sqlite3_reset()] or 4138: ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4139: ** something other than [SQLITE_ROW], the results are undefined. 4140: ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4141: ** are called from a different thread while any of these routines 4142: ** are pending, then the results are undefined. 4143: ** 4144: ** ^The sqlite3_column_type() routine returns the 4145: ** [SQLITE_INTEGER | datatype code] for the initial data type 4146: ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4147: ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 4148: ** returned by sqlite3_column_type() is only meaningful if no type 4149: ** conversions have occurred as described below. After a type conversion, 4150: ** the value returned by sqlite3_column_type() is undefined. Future 4151: ** versions of SQLite may change the behavior of sqlite3_column_type() 4152: ** following a type conversion. 4153: ** 4154: ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4155: ** routine returns the number of bytes in that BLOB or string. 4156: ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4157: ** the string to UTF-8 and then returns the number of bytes. 4158: ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4159: ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4160: ** the number of bytes in that string. 4161: ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4162: ** 4163: ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4164: ** routine returns the number of bytes in that BLOB or string. 4165: ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4166: ** the string to UTF-16 and then returns the number of bytes. 4167: ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4168: ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4169: ** the number of bytes in that string. 4170: ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4171: ** 4172: ** ^The values returned by [sqlite3_column_bytes()] and 4173: ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4174: ** of the string. ^For clarity: the values returned by 4175: ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4176: ** bytes in the string, not the number of characters. 4177: ** 4178: ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4179: ** even empty strings, are always zero-terminated. ^The return 4180: ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4181: ** 4182: ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4183: ** [unprotected sqlite3_value] object. In a multithreaded environment, 4184: ** an unprotected sqlite3_value object may only be used safely with 4185: ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4186: ** If the [unprotected sqlite3_value] object returned by 4187: ** [sqlite3_column_value()] is used in any other way, including calls 4188: ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4189: ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4190: ** 4191: ** These routines attempt to convert the value where appropriate. ^For 4192: ** example, if the internal representation is FLOAT and a text result 4193: ** is requested, [sqlite3_snprintf()] is used internally to perform the 4194: ** conversion automatically. ^(The following table details the conversions 4195: ** that are applied: 4196: ** 4197: ** <blockquote> 4198: ** <table border="1"> 4199: ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4200: ** 4201: ** <tr><td> NULL <td> INTEGER <td> Result is 0 4202: ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4203: ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4204: ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4205: ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4206: ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4207: ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4208: ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4209: ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4210: ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4211: ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4212: ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4213: ** <tr><td> TEXT <td> BLOB <td> No change 4214: ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4215: ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4216: ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4217: ** </table> 4218: ** </blockquote>)^ 4219: ** 4220: ** Note that when type conversions occur, pointers returned by prior 4221: ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4222: ** sqlite3_column_text16() may be invalidated. 4223: ** Type conversions and pointer invalidations might occur 4224: ** in the following cases: 4225: ** 4226: ** <ul> 4227: ** <li> The initial content is a BLOB and sqlite3_column_text() or 4228: ** sqlite3_column_text16() is called. A zero-terminator might 4229: ** need to be added to the string.</li> 4230: ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4231: ** sqlite3_column_text16() is called. The content must be converted 4232: ** to UTF-16.</li> 4233: ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4234: ** sqlite3_column_text() is called. The content must be converted 4235: ** to UTF-8.</li> 4236: ** </ul> 4237: ** 4238: ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4239: ** not invalidate a prior pointer, though of course the content of the buffer 4240: ** that the prior pointer references will have been modified. Other kinds 4241: ** of conversion are done in place when it is possible, but sometimes they 4242: ** are not possible and in those cases prior pointers are invalidated. 4243: ** 4244: ** The safest policy is to invoke these routines 4245: ** in one of the following ways: 4246: ** 4247: ** <ul> 4248: ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4249: ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4250: ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4251: ** </ul> 4252: ** 4253: ** In other words, you should call sqlite3_column_text(), 4254: ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4255: ** into the desired format, then invoke sqlite3_column_bytes() or 4256: ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4257: ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4258: ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4259: ** with calls to sqlite3_column_bytes(). 4260: ** 4261: ** ^The pointers returned are valid until a type conversion occurs as 4262: ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4263: ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4264: ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4265: ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4266: ** [sqlite3_free()]. 4267: ** 4268: ** ^(If a memory allocation error occurs during the evaluation of any 4269: ** of these routines, a default value is returned. The default value 4270: ** is either the integer 0, the floating point number 0.0, or a NULL 4271: ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4272: ** [SQLITE_NOMEM].)^ 4273: */ 4274: SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4275: SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4276: SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4277: SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4278: SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4279: SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4280: SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4281: SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4282: SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4283: SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4284: 4285: /* 4286: ** CAPI3REF: Destroy A Prepared Statement Object 4287: ** DESTRUCTOR: sqlite3_stmt 4288: ** 4289: ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4290: ** ^If the most recent evaluation of the statement encountered no errors 4291: ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4292: ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4293: ** sqlite3_finalize(S) returns the appropriate [error code] or 4294: ** [extended error code]. 4295: ** 4296: ** ^The sqlite3_finalize(S) routine can be called at any point during 4297: ** the life cycle of [prepared statement] S: 4298: ** before statement S is ever evaluated, after 4299: ** one or more calls to [sqlite3_reset()], or after any call 4300: ** to [sqlite3_step()] regardless of whether or not the statement has 4301: ** completed execution. 4302: ** 4303: ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4304: ** 4305: ** The application must finalize every [prepared statement] in order to avoid 4306: ** resource leaks. It is a grievous error for the application to try to use 4307: ** a prepared statement after it has been finalized. Any use of a prepared 4308: ** statement after it has been finalized can result in undefined and 4309: ** undesirable behavior such as segfaults and heap corruption. 4310: */ 4311: SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4312: 4313: /* 4314: ** CAPI3REF: Reset A Prepared Statement Object 4315: ** METHOD: sqlite3_stmt 4316: ** 4317: ** The sqlite3_reset() function is called to reset a [prepared statement] 4318: ** object back to its initial state, ready to be re-executed. 4319: ** ^Any SQL statement variables that had values bound to them using 4320: ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4321: ** Use [sqlite3_clear_bindings()] to reset the bindings. 4322: ** 4323: ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4324: ** back to the beginning of its program. 4325: ** 4326: ** ^If the most recent call to [sqlite3_step(S)] for the 4327: ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4328: ** or if [sqlite3_step(S)] has never before been called on S, 4329: ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4330: ** 4331: ** ^If the most recent call to [sqlite3_step(S)] for the 4332: ** [prepared statement] S indicated an error, then 4333: ** [sqlite3_reset(S)] returns an appropriate [error code]. 4334: ** 4335: ** ^The [sqlite3_reset(S)] interface does not change the values 4336: ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4337: */ 4338: SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4339: 4340: /* 4341: ** CAPI3REF: Create Or Redefine SQL Functions 4342: ** KEYWORDS: {function creation routines} 4343: ** KEYWORDS: {application-defined SQL function} 4344: ** KEYWORDS: {application-defined SQL functions} 4345: ** METHOD: sqlite3 4346: ** 4347: ** ^These functions (collectively known as "function creation routines") 4348: ** are used to add SQL functions or aggregates or to redefine the behavior 4349: ** of existing SQL functions or aggregates. The only differences between 4350: ** these routines are the text encoding expected for 4351: ** the second parameter (the name of the function being created) 4352: ** and the presence or absence of a destructor callback for 4353: ** the application data pointer. 4354: ** 4355: ** ^The first parameter is the [database connection] to which the SQL 4356: ** function is to be added. ^If an application uses more than one database 4357: ** connection then application-defined SQL functions must be added 4358: ** to each database connection separately. 4359: ** 4360: ** ^The second parameter is the name of the SQL function to be created or 4361: ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4362: ** representation, exclusive of the zero-terminator. ^Note that the name 4363: ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4364: ** ^Any attempt to create a function with a longer name 4365: ** will result in [SQLITE_MISUSE] being returned. 4366: ** 4367: ** ^The third parameter (nArg) 4368: ** is the number of arguments that the SQL function or 4369: ** aggregate takes. ^If this parameter is -1, then the SQL function or 4370: ** aggregate may take any number of arguments between 0 and the limit 4371: ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4372: ** parameter is less than -1 or greater than 127 then the behavior is 4373: ** undefined. 4374: ** 4375: ** ^The fourth parameter, eTextRep, specifies what 4376: ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4377: ** its parameters. The application should set this parameter to 4378: ** [SQLITE_UTF16LE] if the function implementation invokes 4379: ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4380: ** implementation invokes [sqlite3_value_text16be()] on an input, or 4381: ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4382: ** otherwise. ^The same SQL function may be registered multiple times using 4383: ** different preferred text encodings, with different implementations for 4384: ** each encoding. 4385: ** ^When multiple implementations of the same function are available, SQLite 4386: ** will pick the one that involves the least amount of data conversion. 4387: ** 4388: ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4389: ** to signal that the function will always return the same result given 4390: ** the same inputs within a single SQL statement. Most SQL functions are 4391: ** deterministic. The built-in [random()] SQL function is an example of a 4392: ** function that is not deterministic. The SQLite query planner is able to 4393: ** perform additional optimizations on deterministic functions, so use 4394: ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4395: ** 4396: ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4397: ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4398: ** 4399: ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4400: ** pointers to C-language functions that implement the SQL function or 4401: ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4402: ** callback only; NULL pointers must be passed as the xStep and xFinal 4403: ** parameters. ^An aggregate SQL function requires an implementation of xStep 4404: ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4405: ** SQL function or aggregate, pass NULL pointers for all three function 4406: ** callbacks. 4407: ** 4408: ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4409: ** then it is destructor for the application data pointer. 4410: ** The destructor is invoked when the function is deleted, either by being 4411: ** overloaded or when the database connection closes.)^ 4412: ** ^The destructor is also invoked if the call to 4413: ** sqlite3_create_function_v2() fails. 4414: ** ^When the destructor callback of the tenth parameter is invoked, it 4415: ** is passed a single argument which is a copy of the application data 4416: ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4417: ** 4418: ** ^It is permitted to register multiple implementations of the same 4419: ** functions with the same name but with either differing numbers of 4420: ** arguments or differing preferred text encodings. ^SQLite will use 4421: ** the implementation that most closely matches the way in which the 4422: ** SQL function is used. ^A function implementation with a non-negative 4423: ** nArg parameter is a better match than a function implementation with 4424: ** a negative nArg. ^A function where the preferred text encoding 4425: ** matches the database encoding is a better 4426: ** match than a function where the encoding is different. 4427: ** ^A function where the encoding difference is between UTF16le and UTF16be 4428: ** is a closer match than a function where the encoding difference is 4429: ** between UTF8 and UTF16. 4430: ** 4431: ** ^Built-in functions may be overloaded by new application-defined functions. 4432: ** 4433: ** ^An application-defined function is permitted to call other 4434: ** SQLite interfaces. However, such calls must not 4435: ** close the database connection nor finalize or reset the prepared 4436: ** statement in which the function is running. 4437: */ 4438: SQLITE_API int sqlite3_create_function( 4439: sqlite3 *db, 4440: const char *zFunctionName, 4441: int nArg, 4442: int eTextRep, 4443: void *pApp, 4444: void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4445: void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4446: void (*xFinal)(sqlite3_context*) 4447: ); 4448: SQLITE_API int sqlite3_create_function16( 4449: sqlite3 *db, 4450: const void *zFunctionName, 4451: int nArg, 4452: int eTextRep, 4453: void *pApp, 4454: void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4455: void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4456: void (*xFinal)(sqlite3_context*) 4457: ); 4458: SQLITE_API int sqlite3_create_function_v2( 4459: sqlite3 *db, 4460: const char *zFunctionName, 4461: int nArg, 4462: int eTextRep, 4463: void *pApp, 4464: void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4465: void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4466: void (*xFinal)(sqlite3_context*), 4467: void(*xDestroy)(void*) 4468: ); 4469: 4470: /* 4471: ** CAPI3REF: Text Encodings 4472: ** 4473: ** These constant define integer codes that represent the various 4474: ** text encodings supported by SQLite. 4475: */ 4476: #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4477: #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4478: #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4479: #define SQLITE_UTF16 4 /* Use native byte order */ 4480: #define SQLITE_ANY 5 /* Deprecated */ 4481: #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4482: 4483: /* 4484: ** CAPI3REF: Function Flags 4485: ** 4486: ** These constants may be ORed together with the 4487: ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4488: ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4489: ** [sqlite3_create_function_v2()]. 4490: */ 4491: #define SQLITE_DETERMINISTIC 0x800 4492: 4493: /* 4494: ** CAPI3REF: Deprecated Functions 4495: ** DEPRECATED 4496: ** 4497: ** These functions are [deprecated]. In order to maintain 4498: ** backwards compatibility with older code, these functions continue 4499: ** to be supported. However, new applications should avoid 4500: ** the use of these functions. To encourage programmers to avoid 4501: ** these functions, we will not explain what they do. 4502: */ 4503: #ifndef SQLITE_OMIT_DEPRECATED 4504: SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4505: SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4506: SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4507: SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4508: SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4509: SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4510: void*,sqlite3_int64); 4511: #endif 4512: 4513: /* 4514: ** CAPI3REF: Obtaining SQL Values 4515: ** METHOD: sqlite3_value 4516: ** 4517: ** The C-language implementation of SQL functions and aggregates uses 4518: ** this set of interface routines to access the parameter values on 4519: ** the function or aggregate. 4520: ** 4521: ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4522: ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4523: ** define callbacks that implement the SQL functions and aggregates. 4524: ** The 3rd parameter to these callbacks is an array of pointers to 4525: ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4526: ** each parameter to the SQL function. These routines are used to 4527: ** extract values from the [sqlite3_value] objects. 4528: ** 4529: ** These routines work only with [protected sqlite3_value] objects. 4530: ** Any attempt to use these routines on an [unprotected sqlite3_value] 4531: ** object results in undefined behavior. 4532: ** 4533: ** ^These routines work just like the corresponding [column access functions] 4534: ** except that these routines take a single [protected sqlite3_value] object 4535: ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4536: ** 4537: ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4538: ** in the native byte-order of the host machine. ^The 4539: ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4540: ** extract UTF-16 strings as big-endian and little-endian respectively. 4541: ** 4542: ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4543: ** numeric affinity to the value. This means that an attempt is 4544: ** made to convert the value to an integer or floating point. If 4545: ** such a conversion is possible without loss of information (in other 4546: ** words, if the value is a string that looks like a number) 4547: ** then the conversion is performed. Otherwise no conversion occurs. 4548: ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4549: ** 4550: ** Please pay particular attention to the fact that the pointer returned 4551: ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4552: ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4553: ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4554: ** or [sqlite3_value_text16()]. 4555: ** 4556: ** These routines must be called from the same thread as 4557: ** the SQL function that supplied the [sqlite3_value*] parameters. 4558: */ 4559: SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4560: SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4561: SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4562: SQLITE_API double sqlite3_value_double(sqlite3_value*); 4563: SQLITE_API int sqlite3_value_int(sqlite3_value*); 4564: SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4565: SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4566: SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4567: SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4568: SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4569: SQLITE_API int sqlite3_value_type(sqlite3_value*); 4570: SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4571: 4572: /* 4573: ** CAPI3REF: Finding The Subtype Of SQL Values 4574: ** METHOD: sqlite3_value 4575: ** 4576: ** The sqlite3_value_subtype(V) function returns the subtype for 4577: ** an [application-defined SQL function] argument V. The subtype 4578: ** information can be used to pass a limited amount of context from 4579: ** one SQL function to another. Use the [sqlite3_result_subtype()] 4580: ** routine to set the subtype for the return value of an SQL function. 4581: ** 4582: ** SQLite makes no use of subtype itself. It merely passes the subtype 4583: ** from the result of one [application-defined SQL function] into the 4584: ** input of another. 4585: */ 4586: SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 4587: 4588: /* 4589: ** CAPI3REF: Copy And Free SQL Values 4590: ** METHOD: sqlite3_value 4591: ** 4592: ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4593: ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4594: ** is a [protected sqlite3_value] object even if the input is not. 4595: ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4596: ** memory allocation fails. 4597: ** 4598: ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4599: ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4600: ** then sqlite3_value_free(V) is a harmless no-op. 4601: */ 4602: SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4603: SQLITE_API void sqlite3_value_free(sqlite3_value*); 4604: 4605: /* 4606: ** CAPI3REF: Obtain Aggregate Function Context 4607: ** METHOD: sqlite3_context 4608: ** 4609: ** Implementations of aggregate SQL functions use this 4610: ** routine to allocate memory for storing their state. 4611: ** 4612: ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4613: ** for a particular aggregate function, SQLite 4614: ** allocates N of memory, zeroes out that memory, and returns a pointer 4615: ** to the new memory. ^On second and subsequent calls to 4616: ** sqlite3_aggregate_context() for the same aggregate function instance, 4617: ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4618: ** called once for each invocation of the xStep callback and then one 4619: ** last time when the xFinal callback is invoked. ^(When no rows match 4620: ** an aggregate query, the xStep() callback of the aggregate function 4621: ** implementation is never called and xFinal() is called exactly once. 4622: ** In those cases, sqlite3_aggregate_context() might be called for the 4623: ** first time from within xFinal().)^ 4624: ** 4625: ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4626: ** when first called if N is less than or equal to zero or if a memory 4627: ** allocate error occurs. 4628: ** 4629: ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4630: ** determined by the N parameter on first successful call. Changing the 4631: ** value of N in subsequent call to sqlite3_aggregate_context() within 4632: ** the same aggregate function instance will not resize the memory 4633: ** allocation.)^ Within the xFinal callback, it is customary to set 4634: ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4635: ** pointless memory allocations occur. 4636: ** 4637: ** ^SQLite automatically frees the memory allocated by 4638: ** sqlite3_aggregate_context() when the aggregate query concludes. 4639: ** 4640: ** The first parameter must be a copy of the 4641: ** [sqlite3_context | SQL function context] that is the first parameter 4642: ** to the xStep or xFinal callback routine that implements the aggregate 4643: ** function. 4644: ** 4645: ** This routine must be called from the same thread in which 4646: ** the aggregate SQL function is running. 4647: */ 4648: SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4649: 4650: /* 4651: ** CAPI3REF: User Data For Functions 4652: ** METHOD: sqlite3_context 4653: ** 4654: ** ^The sqlite3_user_data() interface returns a copy of 4655: ** the pointer that was the pUserData parameter (the 5th parameter) 4656: ** of the [sqlite3_create_function()] 4657: ** and [sqlite3_create_function16()] routines that originally 4658: ** registered the application defined function. 4659: ** 4660: ** This routine must be called from the same thread in which 4661: ** the application-defined function is running. 4662: */ 4663: SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4664: 4665: /* 4666: ** CAPI3REF: Database Connection For Functions 4667: ** METHOD: sqlite3_context 4668: ** 4669: ** ^The sqlite3_context_db_handle() interface returns a copy of 4670: ** the pointer to the [database connection] (the 1st parameter) 4671: ** of the [sqlite3_create_function()] 4672: ** and [sqlite3_create_function16()] routines that originally 4673: ** registered the application defined function. 4674: */ 4675: SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4676: 4677: /* 4678: ** CAPI3REF: Function Auxiliary Data 4679: ** METHOD: sqlite3_context 4680: ** 4681: ** These functions may be used by (non-aggregate) SQL functions to 4682: ** associate metadata with argument values. If the same value is passed to 4683: ** multiple invocations of the same SQL function during query execution, under 4684: ** some circumstances the associated metadata may be preserved. An example 4685: ** of where this might be useful is in a regular-expression matching 4686: ** function. The compiled version of the regular expression can be stored as 4687: ** metadata associated with the pattern string. 4688: ** Then as long as the pattern string remains the same, 4689: ** the compiled regular expression can be reused on multiple 4690: ** invocations of the same function. 4691: ** 4692: ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4693: ** associated by the sqlite3_set_auxdata() function with the Nth argument 4694: ** value to the application-defined function. ^If there is no metadata 4695: ** associated with the function argument, this sqlite3_get_auxdata() interface 4696: ** returns a NULL pointer. 4697: ** 4698: ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4699: ** argument of the application-defined function. ^Subsequent 4700: ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4701: ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4702: ** NULL if the metadata has been discarded. 4703: ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4704: ** SQLite will invoke the destructor function X with parameter P exactly 4705: ** once, when the metadata is discarded. 4706: ** SQLite is free to discard the metadata at any time, including: <ul> 4707: ** <li> ^(when the corresponding function parameter changes)^, or 4708: ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4709: ** SQL statement)^, or 4710: ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4711: ** parameter)^, or 4712: ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4713: ** allocation error occurs.)^ </ul> 4714: ** 4715: ** Note the last bullet in particular. The destructor X in 4716: ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4717: ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4718: ** should be called near the end of the function implementation and the 4719: ** function implementation should not make any use of P after 4720: ** sqlite3_set_auxdata() has been called. 4721: ** 4722: ** ^(In practice, metadata is preserved between function calls for 4723: ** function parameters that are compile-time constants, including literal 4724: ** values and [parameters] and expressions composed from the same.)^ 4725: ** 4726: ** These routines must be called from the same thread in which 4727: ** the SQL function is running. 4728: */ 4729: SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 4730: SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4731: 4732: 4733: /* 4734: ** CAPI3REF: Constants Defining Special Destructor Behavior 4735: ** 4736: ** These are special values for the destructor that is passed in as the 4737: ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4738: ** argument is SQLITE_STATIC, it means that the content pointer is constant 4739: ** and will never change. It does not need to be destroyed. ^The 4740: ** SQLITE_TRANSIENT value means that the content will likely change in 4741: ** the near future and that SQLite should make its own private copy of 4742: ** the content before returning. 4743: ** 4744: ** The typedef is necessary to work around problems in certain 4745: ** C++ compilers. 4746: */ 4747: typedef void (*sqlite3_destructor_type)(void*); 4748: #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4749: #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4750: 4751: /* 4752: ** CAPI3REF: Setting The Result Of An SQL Function 4753: ** METHOD: sqlite3_context 4754: ** 4755: ** These routines are used by the xFunc or xFinal callbacks that 4756: ** implement SQL functions and aggregates. See 4757: ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4758: ** for additional information. 4759: ** 4760: ** These functions work very much like the [parameter binding] family of 4761: ** functions used to bind values to host parameters in prepared statements. 4762: ** Refer to the [SQL parameter] documentation for additional information. 4763: ** 4764: ** ^The sqlite3_result_blob() interface sets the result from 4765: ** an application-defined function to be the BLOB whose content is pointed 4766: ** to by the second parameter and which is N bytes long where N is the 4767: ** third parameter. 4768: ** 4769: ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4770: ** interfaces set the result of the application-defined function to be 4771: ** a BLOB containing all zero bytes and N bytes in size. 4772: ** 4773: ** ^The sqlite3_result_double() interface sets the result from 4774: ** an application-defined function to be a floating point value specified 4775: ** by its 2nd argument. 4776: ** 4777: ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4778: ** cause the implemented SQL function to throw an exception. 4779: ** ^SQLite uses the string pointed to by the 4780: ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4781: ** as the text of an error message. ^SQLite interprets the error 4782: ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4783: ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4784: ** byte order. ^If the third parameter to sqlite3_result_error() 4785: ** or sqlite3_result_error16() is negative then SQLite takes as the error 4786: ** message all text up through the first zero character. 4787: ** ^If the third parameter to sqlite3_result_error() or 4788: ** sqlite3_result_error16() is non-negative then SQLite takes that many 4789: ** bytes (not characters) from the 2nd parameter as the error message. 4790: ** ^The sqlite3_result_error() and sqlite3_result_error16() 4791: ** routines make a private copy of the error message text before 4792: ** they return. Hence, the calling function can deallocate or 4793: ** modify the text after they return without harm. 4794: ** ^The sqlite3_result_error_code() function changes the error code 4795: ** returned by SQLite as a result of an error in a function. ^By default, 4796: ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4797: ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4798: ** 4799: ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4800: ** error indicating that a string or BLOB is too long to represent. 4801: ** 4802: ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4803: ** error indicating that a memory allocation failed. 4804: ** 4805: ** ^The sqlite3_result_int() interface sets the return value 4806: ** of the application-defined function to be the 32-bit signed integer 4807: ** value given in the 2nd argument. 4808: ** ^The sqlite3_result_int64() interface sets the return value 4809: ** of the application-defined function to be the 64-bit signed integer 4810: ** value given in the 2nd argument. 4811: ** 4812: ** ^The sqlite3_result_null() interface sets the return value 4813: ** of the application-defined function to be NULL. 4814: ** 4815: ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4816: ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4817: ** set the return value of the application-defined function to be 4818: ** a text string which is represented as UTF-8, UTF-16 native byte order, 4819: ** UTF-16 little endian, or UTF-16 big endian, respectively. 4820: ** ^The sqlite3_result_text64() interface sets the return value of an 4821: ** application-defined function to be a text string in an encoding 4822: ** specified by the fifth (and last) parameter, which must be one 4823: ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4824: ** ^SQLite takes the text result from the application from 4825: ** the 2nd parameter of the sqlite3_result_text* interfaces. 4826: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4827: ** is negative, then SQLite takes result text from the 2nd parameter 4828: ** through the first zero character. 4829: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4830: ** is non-negative, then as many bytes (not characters) of the text 4831: ** pointed to by the 2nd parameter are taken as the application-defined 4832: ** function result. If the 3rd parameter is non-negative, then it 4833: ** must be the byte offset into the string where the NUL terminator would 4834: ** appear if the string where NUL terminated. If any NUL characters occur 4835: ** in the string at a byte offset that is less than the value of the 3rd 4836: ** parameter, then the resulting string will contain embedded NULs and the 4837: ** result of expressions operating on strings with embedded NULs is undefined. 4838: ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4839: ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4840: ** function as the destructor on the text or BLOB result when it has 4841: ** finished using that result. 4842: ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4843: ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4844: ** assumes that the text or BLOB result is in constant space and does not 4845: ** copy the content of the parameter nor call a destructor on the content 4846: ** when it has finished using that result. 4847: ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4848: ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4849: ** then SQLite makes a copy of the result into space obtained from 4850: ** from [sqlite3_malloc()] before it returns. 4851: ** 4852: ** ^The sqlite3_result_value() interface sets the result of 4853: ** the application-defined function to be a copy of the 4854: ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4855: ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4856: ** so that the [sqlite3_value] specified in the parameter may change or 4857: ** be deallocated after sqlite3_result_value() returns without harm. 4858: ** ^A [protected sqlite3_value] object may always be used where an 4859: ** [unprotected sqlite3_value] object is required, so either 4860: ** kind of [sqlite3_value] object can be used with this interface. 4861: ** 4862: ** If these routines are called from within the different thread 4863: ** than the one containing the application-defined function that received 4864: ** the [sqlite3_context] pointer, the results are undefined. 4865: */ 4866: SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4867: SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 4868: sqlite3_uint64,void(*)(void*)); 4869: SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4870: SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4871: SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4872: SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4873: SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 4874: SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 4875: SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 4876: SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4877: SQLITE_API void sqlite3_result_null(sqlite3_context*); 4878: SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4879: SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4880: void(*)(void*), unsigned char encoding); 4881: SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4882: SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4883: SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4884: SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4885: SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 4886: SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4887: 4888: 4889: /* 4890: ** CAPI3REF: Setting The Subtype Of An SQL Function 4891: ** METHOD: sqlite3_context 4892: ** 4893: ** The sqlite3_result_subtype(C,T) function causes the subtype of 4894: ** the result from the [application-defined SQL function] with 4895: ** [sqlite3_context] C to be the value T. Only the lower 8 bits 4896: ** of the subtype T are preserved in current versions of SQLite; 4897: ** higher order bits are discarded. 4898: ** The number of subtype bytes preserved by SQLite might increase 4899: ** in future releases of SQLite. 4900: */ 4901: SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 4902: 4903: /* 4904: ** CAPI3REF: Define New Collating Sequences 4905: ** METHOD: sqlite3 4906: ** 4907: ** ^These functions add, remove, or modify a [collation] associated 4908: ** with the [database connection] specified as the first argument. 4909: ** 4910: ** ^The name of the collation is a UTF-8 string 4911: ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4912: ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4913: ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4914: ** considered to be the same name. 4915: ** 4916: ** ^(The third argument (eTextRep) must be one of the constants: 4917: ** <ul> 4918: ** <li> [SQLITE_UTF8], 4919: ** <li> [SQLITE_UTF16LE], 4920: ** <li> [SQLITE_UTF16BE], 4921: ** <li> [SQLITE_UTF16], or 4922: ** <li> [SQLITE_UTF16_ALIGNED]. 4923: ** </ul>)^ 4924: ** ^The eTextRep argument determines the encoding of strings passed 4925: ** to the collating function callback, xCallback. 4926: ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4927: ** force strings to be UTF16 with native byte order. 4928: ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4929: ** on an even byte address. 4930: ** 4931: ** ^The fourth argument, pArg, is an application data pointer that is passed 4932: ** through as the first argument to the collating function callback. 4933: ** 4934: ** ^The fifth argument, xCallback, is a pointer to the collating function. 4935: ** ^Multiple collating functions can be registered using the same name but 4936: ** with different eTextRep parameters and SQLite will use whichever 4937: ** function requires the least amount of data transformation. 4938: ** ^If the xCallback argument is NULL then the collating function is 4939: ** deleted. ^When all collating functions having the same name are deleted, 4940: ** that collation is no longer usable. 4941: ** 4942: ** ^The collating function callback is invoked with a copy of the pArg 4943: ** application data pointer and with two strings in the encoding specified 4944: ** by the eTextRep argument. The collating function must return an 4945: ** integer that is negative, zero, or positive 4946: ** if the first string is less than, equal to, or greater than the second, 4947: ** respectively. A collating function must always return the same answer 4948: ** given the same inputs. If two or more collating functions are registered 4949: ** to the same collation name (using different eTextRep values) then all 4950: ** must give an equivalent answer when invoked with equivalent strings. 4951: ** The collating function must obey the following properties for all 4952: ** strings A, B, and C: 4953: ** 4954: ** <ol> 4955: ** <li> If A==B then B==A. 4956: ** <li> If A==B and B==C then A==C. 4957: ** <li> If A<B THEN B>A. 4958: ** <li> If A<B and B<C then A<C. 4959: ** </ol> 4960: ** 4961: ** If a collating function fails any of the above constraints and that 4962: ** collating function is registered and used, then the behavior of SQLite 4963: ** is undefined. 4964: ** 4965: ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4966: ** with the addition that the xDestroy callback is invoked on pArg when 4967: ** the collating function is deleted. 4968: ** ^Collating functions are deleted when they are overridden by later 4969: ** calls to the collation creation functions or when the 4970: ** [database connection] is closed using [sqlite3_close()]. 4971: ** 4972: ** ^The xDestroy callback is <u>not</u> called if the 4973: ** sqlite3_create_collation_v2() function fails. Applications that invoke 4974: ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4975: ** check the return code and dispose of the application data pointer 4976: ** themselves rather than expecting SQLite to deal with it for them. 4977: ** This is different from every other SQLite interface. The inconsistency 4978: ** is unfortunate but cannot be changed without breaking backwards 4979: ** compatibility. 4980: ** 4981: ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4982: */ 4983: SQLITE_API int sqlite3_create_collation( 4984: sqlite3*, 4985: const char *zName, 4986: int eTextRep, 4987: void *pArg, 4988: int(*xCompare)(void*,int,const void*,int,const void*) 4989: ); 4990: SQLITE_API int sqlite3_create_collation_v2( 4991: sqlite3*, 4992: const char *zName, 4993: int eTextRep, 4994: void *pArg, 4995: int(*xCompare)(void*,int,const void*,int,const void*), 4996: void(*xDestroy)(void*) 4997: ); 4998: SQLITE_API int sqlite3_create_collation16( 4999: sqlite3*, 5000: const void *zName, 5001: int eTextRep, 5002: void *pArg, 5003: int(*xCompare)(void*,int,const void*,int,const void*) 5004: ); 5005: 5006: /* 5007: ** CAPI3REF: Collation Needed Callbacks 5008: ** METHOD: sqlite3 5009: ** 5010: ** ^To avoid having to register all collation sequences before a database 5011: ** can be used, a single callback function may be registered with the 5012: ** [database connection] to be invoked whenever an undefined collation 5013: ** sequence is required. 5014: ** 5015: ** ^If the function is registered using the sqlite3_collation_needed() API, 5016: ** then it is passed the names of undefined collation sequences as strings 5017: ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5018: ** the names are passed as UTF-16 in machine native byte order. 5019: ** ^A call to either function replaces the existing collation-needed callback. 5020: ** 5021: ** ^(When the callback is invoked, the first argument passed is a copy 5022: ** of the second argument to sqlite3_collation_needed() or 5023: ** sqlite3_collation_needed16(). The second argument is the database 5024: ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5025: ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5026: ** sequence function required. The fourth parameter is the name of the 5027: ** required collation sequence.)^ 5028: ** 5029: ** The callback function should register the desired collation using 5030: ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5031: ** [sqlite3_create_collation_v2()]. 5032: */ 5033: SQLITE_API int sqlite3_collation_needed( 5034: sqlite3*, 5035: void*, 5036: void(*)(void*,sqlite3*,int eTextRep,const char*) 5037: ); 5038: SQLITE_API int sqlite3_collation_needed16( 5039: sqlite3*, 5040: void*, 5041: void(*)(void*,sqlite3*,int eTextRep,const void*) 5042: ); 5043: 5044: #ifdef SQLITE_HAS_CODEC 5045: /* 5046: ** Specify the key for an encrypted database. This routine should be 5047: ** called right after sqlite3_open(). 5048: ** 5049: ** The code to implement this API is not available in the public release 5050: ** of SQLite. 5051: */ 5052: SQLITE_API int sqlite3_key( 5053: sqlite3 *db, /* Database to be rekeyed */ 5054: const void *pKey, int nKey /* The key */ 5055: ); 5056: SQLITE_API int sqlite3_key_v2( 5057: sqlite3 *db, /* Database to be rekeyed */ 5058: const char *zDbName, /* Name of the database */ 5059: const void *pKey, int nKey /* The key */ 5060: ); 5061: 5062: /* 5063: ** Change the key on an open database. If the current database is not 5064: ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5065: ** database is decrypted. 5066: ** 5067: ** The code to implement this API is not available in the public release 5068: ** of SQLite. 5069: */ 5070: SQLITE_API int sqlite3_rekey( 5071: sqlite3 *db, /* Database to be rekeyed */ 5072: const void *pKey, int nKey /* The new key */ 5073: ); 5074: SQLITE_API int sqlite3_rekey_v2( 5075: sqlite3 *db, /* Database to be rekeyed */ 5076: const char *zDbName, /* Name of the database */ 5077: const void *pKey, int nKey /* The new key */ 5078: ); 5079: 5080: /* 5081: ** Specify the activation key for a SEE database. Unless 5082: ** activated, none of the SEE routines will work. 5083: */ 5084: SQLITE_API void sqlite3_activate_see( 5085: const char *zPassPhrase /* Activation phrase */ 5086: ); 5087: #endif 5088: 5089: #ifdef SQLITE_ENABLE_CEROD 5090: /* 5091: ** Specify the activation key for a CEROD database. Unless 5092: ** activated, none of the CEROD routines will work. 5093: */ 5094: SQLITE_API void sqlite3_activate_cerod( 5095: const char *zPassPhrase /* Activation phrase */ 5096: ); 5097: #endif 5098: 5099: /* 5100: ** CAPI3REF: Suspend Execution For A Short Time 5101: ** 5102: ** The sqlite3_sleep() function causes the current thread to suspend execution 5103: ** for at least a number of milliseconds specified in its parameter. 5104: ** 5105: ** If the operating system does not support sleep requests with 5106: ** millisecond time resolution, then the time will be rounded up to 5107: ** the nearest second. The number of milliseconds of sleep actually 5108: ** requested from the operating system is returned. 5109: ** 5110: ** ^SQLite implements this interface by calling the xSleep() 5111: ** method of the default [sqlite3_vfs] object. If the xSleep() method 5112: ** of the default VFS is not implemented correctly, or not implemented at 5113: ** all, then the behavior of sqlite3_sleep() may deviate from the description 5114: ** in the previous paragraphs. 5115: */ 5116: SQLITE_API int sqlite3_sleep(int); 5117: 5118: /* 5119: ** CAPI3REF: Name Of The Folder Holding Temporary Files 5120: ** 5121: ** ^(If this global variable is made to point to a string which is 5122: ** the name of a folder (a.k.a. directory), then all temporary files 5123: ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5124: ** will be placed in that directory.)^ ^If this variable 5125: ** is a NULL pointer, then SQLite performs a search for an appropriate 5126: ** temporary file directory. 5127: ** 5128: ** Applications are strongly discouraged from using this global variable. 5129: ** It is required to set a temporary folder on Windows Runtime (WinRT). 5130: ** But for all other platforms, it is highly recommended that applications 5131: ** neither read nor write this variable. This global variable is a relic 5132: ** that exists for backwards compatibility of legacy applications and should 5133: ** be avoided in new projects. 5134: ** 5135: ** It is not safe to read or modify this variable in more than one 5136: ** thread at a time. It is not safe to read or modify this variable 5137: ** if a [database connection] is being used at the same time in a separate 5138: ** thread. 5139: ** It is intended that this variable be set once 5140: ** as part of process initialization and before any SQLite interface 5141: ** routines have been called and that this variable remain unchanged 5142: ** thereafter. 5143: ** 5144: ** ^The [temp_store_directory pragma] may modify this variable and cause 5145: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5146: ** the [temp_store_directory pragma] always assumes that any string 5147: ** that this variable points to is held in memory obtained from 5148: ** [sqlite3_malloc] and the pragma may attempt to free that memory 5149: ** using [sqlite3_free]. 5150: ** Hence, if this variable is modified directly, either it should be 5151: ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5152: ** or else the use of the [temp_store_directory pragma] should be avoided. 5153: ** Except when requested by the [temp_store_directory pragma], SQLite 5154: ** does not free the memory that sqlite3_temp_directory points to. If 5155: ** the application wants that memory to be freed, it must do 5156: ** so itself, taking care to only do so after all [database connection] 5157: ** objects have been destroyed. 5158: ** 5159: ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5160: ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5161: ** features that require the use of temporary files may fail. Here is an 5162: ** example of how to do this using C++ with the Windows Runtime: 5163: ** 5164: ** <blockquote><pre> 5165: ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5166: **   TemporaryFolder->Path->Data(); 5167: ** char zPathBuf[MAX_PATH + 1]; 5168: ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5169: ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5170: **   NULL, NULL); 5171: ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5172: ** </pre></blockquote> 5173: */ 5174: SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5175: 5176: /* 5177: ** CAPI3REF: Name Of The Folder Holding Database Files 5178: ** 5179: ** ^(If this global variable is made to point to a string which is 5180: ** the name of a folder (a.k.a. directory), then all database files 5181: ** specified with a relative pathname and created or accessed by 5182: ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5183: ** to be relative to that directory.)^ ^If this variable is a NULL 5184: ** pointer, then SQLite assumes that all database files specified 5185: ** with a relative pathname are relative to the current directory 5186: ** for the process. Only the windows VFS makes use of this global 5187: ** variable; it is ignored by the unix VFS. 5188: ** 5189: ** Changing the value of this variable while a database connection is 5190: ** open can result in a corrupt database. 5191: ** 5192: ** It is not safe to read or modify this variable in more than one 5193: ** thread at a time. It is not safe to read or modify this variable 5194: ** if a [database connection] is being used at the same time in a separate 5195: ** thread. 5196: ** It is intended that this variable be set once 5197: ** as part of process initialization and before any SQLite interface 5198: ** routines have been called and that this variable remain unchanged 5199: ** thereafter. 5200: ** 5201: ** ^The [data_store_directory pragma] may modify this variable and cause 5202: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5203: ** the [data_store_directory pragma] always assumes that any string 5204: ** that this variable points to is held in memory obtained from 5205: ** [sqlite3_malloc] and the pragma may attempt to free that memory 5206: ** using [sqlite3_free]. 5207: ** Hence, if this variable is modified directly, either it should be 5208: ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5209: ** or else the use of the [data_store_directory pragma] should be avoided. 5210: */ 5211: SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5212: 5213: /* 5214: ** CAPI3REF: Test For Auto-Commit Mode 5215: ** KEYWORDS: {autocommit mode} 5216: ** METHOD: sqlite3 5217: ** 5218: ** ^The sqlite3_get_autocommit() interface returns non-zero or 5219: ** zero if the given database connection is or is not in autocommit mode, 5220: ** respectively. ^Autocommit mode is on by default. 5221: ** ^Autocommit mode is disabled by a [BEGIN] statement. 5222: ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5223: ** 5224: ** If certain kinds of errors occur on a statement within a multi-statement 5225: ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5226: ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5227: ** transaction might be rolled back automatically. The only way to 5228: ** find out whether SQLite automatically rolled back the transaction after 5229: ** an error is to use this function. 5230: ** 5231: ** If another thread changes the autocommit status of the database 5232: ** connection while this routine is running, then the return value 5233: ** is undefined. 5234: */ 5235: SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5236: 5237: /* 5238: ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5239: ** METHOD: sqlite3_stmt 5240: ** 5241: ** ^The sqlite3_db_handle interface returns the [database connection] handle 5242: ** to which a [prepared statement] belongs. ^The [database connection] 5243: ** returned by sqlite3_db_handle is the same [database connection] 5244: ** that was the first argument 5245: ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5246: ** create the statement in the first place. 5247: */ 5248: SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5249: 5250: /* 5251: ** CAPI3REF: Return The Filename For A Database Connection 5252: ** METHOD: sqlite3 5253: ** 5254: ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5255: ** associated with database N of connection D. ^The main database file 5256: ** has the name "main". If there is no attached database N on the database 5257: ** connection D, or if database N is a temporary or in-memory database, then 5258: ** a NULL pointer is returned. 5259: ** 5260: ** ^The filename returned by this function is the output of the 5261: ** xFullPathname method of the [VFS]. ^In other words, the filename 5262: ** will be an absolute pathname, even if the filename used 5263: ** to open the database originally was a URI or relative pathname. 5264: */ 5265: SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5266: 5267: /* 5268: ** CAPI3REF: Determine if a database is read-only 5269: ** METHOD: sqlite3 5270: ** 5271: ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5272: ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5273: ** the name of a database on connection D. 5274: */ 5275: SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5276: 5277: /* 5278: ** CAPI3REF: Find the next prepared statement 5279: ** METHOD: sqlite3 5280: ** 5281: ** ^This interface returns a pointer to the next [prepared statement] after 5282: ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5283: ** then this interface returns a pointer to the first prepared statement 5284: ** associated with the database connection pDb. ^If no prepared statement 5285: ** satisfies the conditions of this routine, it returns NULL. 5286: ** 5287: ** The [database connection] pointer D in a call to 5288: ** [sqlite3_next_stmt(D,S)] must refer to an open database 5289: ** connection and in particular must not be a NULL pointer. 5290: */ 5291: SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5292: 5293: /* 5294: ** CAPI3REF: Commit And Rollback Notification Callbacks 5295: ** METHOD: sqlite3 5296: ** 5297: ** ^The sqlite3_commit_hook() interface registers a callback 5298: ** function to be invoked whenever a transaction is [COMMIT | committed]. 5299: ** ^Any callback set by a previous call to sqlite3_commit_hook() 5300: ** for the same database connection is overridden. 5301: ** ^The sqlite3_rollback_hook() interface registers a callback 5302: ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5303: ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5304: ** for the same database connection is overridden. 5305: ** ^The pArg argument is passed through to the callback. 5306: ** ^If the callback on a commit hook function returns non-zero, 5307: ** then the commit is converted into a rollback. 5308: ** 5309: ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5310: ** return the P argument from the previous call of the same function 5311: ** on the same [database connection] D, or NULL for 5312: ** the first call for each function on D. 5313: ** 5314: ** The commit and rollback hook callbacks are not reentrant. 5315: ** The callback implementation must not do anything that will modify 5316: ** the database connection that invoked the callback. Any actions 5317: ** to modify the database connection must be deferred until after the 5318: ** completion of the [sqlite3_step()] call that triggered the commit 5319: ** or rollback hook in the first place. 5320: ** Note that running any other SQL statements, including SELECT statements, 5321: ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5322: ** the database connections for the meaning of "modify" in this paragraph. 5323: ** 5324: ** ^Registering a NULL function disables the callback. 5325: ** 5326: ** ^When the commit hook callback routine returns zero, the [COMMIT] 5327: ** operation is allowed to continue normally. ^If the commit hook 5328: ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5329: ** ^The rollback hook is invoked on a rollback that results from a commit 5330: ** hook returning non-zero, just as it would be with any other rollback. 5331: ** 5332: ** ^For the purposes of this API, a transaction is said to have been 5333: ** rolled back if an explicit "ROLLBACK" statement is executed, or 5334: ** an error or constraint causes an implicit rollback to occur. 5335: ** ^The rollback callback is not invoked if a transaction is 5336: ** automatically rolled back because the database connection is closed. 5337: ** 5338: ** See also the [sqlite3_update_hook()] interface. 5339: */ 5340: SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5341: SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5342: 5343: /* 5344: ** CAPI3REF: Data Change Notification Callbacks 5345: ** METHOD: sqlite3 5346: ** 5347: ** ^The sqlite3_update_hook() interface registers a callback function 5348: ** with the [database connection] identified by the first argument 5349: ** to be invoked whenever a row is updated, inserted or deleted in 5350: ** a [rowid table]. 5351: ** ^Any callback set by a previous call to this function 5352: ** for the same database connection is overridden. 5353: ** 5354: ** ^The second argument is a pointer to the function to invoke when a 5355: ** row is updated, inserted or deleted in a rowid table. 5356: ** ^The first argument to the callback is a copy of the third argument 5357: ** to sqlite3_update_hook(). 5358: ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5359: ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5360: ** to be invoked. 5361: ** ^The third and fourth arguments to the callback contain pointers to the 5362: ** database and table name containing the affected row. 5363: ** ^The final callback parameter is the [rowid] of the row. 5364: ** ^In the case of an update, this is the [rowid] after the update takes place. 5365: ** 5366: ** ^(The update hook is not invoked when internal system tables are 5367: ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5368: ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5369: ** 5370: ** ^In the current implementation, the update hook 5371: ** is not invoked when duplication rows are deleted because of an 5372: ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5373: ** invoked when rows are deleted using the [truncate optimization]. 5374: ** The exceptions defined in this paragraph might change in a future 5375: ** release of SQLite. 5376: ** 5377: ** The update hook implementation must not do anything that will modify 5378: ** the database connection that invoked the update hook. Any actions 5379: ** to modify the database connection must be deferred until after the 5380: ** completion of the [sqlite3_step()] call that triggered the update hook. 5381: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5382: ** database connections for the meaning of "modify" in this paragraph. 5383: ** 5384: ** ^The sqlite3_update_hook(D,C,P) function 5385: ** returns the P argument from the previous call 5386: ** on the same [database connection] D, or NULL for 5387: ** the first call on D. 5388: ** 5389: ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5390: ** and [sqlite3_preupdate_hook()] interfaces. 5391: */ 5392: SQLITE_API void *sqlite3_update_hook( 5393: sqlite3*, 5394: void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5395: void* 5396: ); 5397: 5398: /* 5399: ** CAPI3REF: Enable Or Disable Shared Pager Cache 5400: ** 5401: ** ^(This routine enables or disables the sharing of the database cache 5402: ** and schema data structures between [database connection | connections] 5403: ** to the same database. Sharing is enabled if the argument is true 5404: ** and disabled if the argument is false.)^ 5405: ** 5406: ** ^Cache sharing is enabled and disabled for an entire process. 5407: ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5408: ** sharing was enabled or disabled for each thread separately. 5409: ** 5410: ** ^(The cache sharing mode set by this interface effects all subsequent 5411: ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5412: ** Existing database connections continue use the sharing mode 5413: ** that was in effect at the time they were opened.)^ 5414: ** 5415: ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5416: ** successfully. An [error code] is returned otherwise.)^ 5417: ** 5418: ** ^Shared cache is disabled by default. But this might change in 5419: ** future releases of SQLite. Applications that care about shared 5420: ** cache setting should set it explicitly. 5421: ** 5422: ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5423: ** and will always return SQLITE_MISUSE. On those systems, 5424: ** shared cache mode should be enabled per-database connection via 5425: ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5426: ** 5427: ** This interface is threadsafe on processors where writing a 5428: ** 32-bit integer is atomic. 5429: ** 5430: ** See Also: [SQLite Shared-Cache Mode] 5431: */ 5432: SQLITE_API int sqlite3_enable_shared_cache(int); 5433: 5434: /* 5435: ** CAPI3REF: Attempt To Free Heap Memory 5436: ** 5437: ** ^The sqlite3_release_memory() interface attempts to free N bytes 5438: ** of heap memory by deallocating non-essential memory allocations 5439: ** held by the database library. Memory used to cache database 5440: ** pages to improve performance is an example of non-essential memory. 5441: ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5442: ** which might be more or less than the amount requested. 5443: ** ^The sqlite3_release_memory() routine is a no-op returning zero 5444: ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5445: ** 5446: ** See also: [sqlite3_db_release_memory()] 5447: */ 5448: SQLITE_API int sqlite3_release_memory(int); 5449: 5450: /* 5451: ** CAPI3REF: Free Memory Used By A Database Connection 5452: ** METHOD: sqlite3 5453: ** 5454: ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5455: ** memory as possible from database connection D. Unlike the 5456: ** [sqlite3_release_memory()] interface, this interface is in effect even 5457: ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5458: ** omitted. 5459: ** 5460: ** See also: [sqlite3_release_memory()] 5461: */ 5462: SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5463: 5464: /* 5465: ** CAPI3REF: Impose A Limit On Heap Size 5466: ** 5467: ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5468: ** soft limit on the amount of heap memory that may be allocated by SQLite. 5469: ** ^SQLite strives to keep heap memory utilization below the soft heap 5470: ** limit by reducing the number of pages held in the page cache 5471: ** as heap memory usages approaches the limit. 5472: ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5473: ** below the limit, it will exceed the limit rather than generate 5474: ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5475: ** is advisory only. 5476: ** 5477: ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5478: ** the soft heap limit prior to the call, or negative in the case of an 5479: ** error. ^If the argument N is negative 5480: ** then no change is made to the soft heap limit. Hence, the current 5481: ** size of the soft heap limit can be determined by invoking 5482: ** sqlite3_soft_heap_limit64() with a negative argument. 5483: ** 5484: ** ^If the argument N is zero then the soft heap limit is disabled. 5485: ** 5486: ** ^(The soft heap limit is not enforced in the current implementation 5487: ** if one or more of following conditions are true: 5488: ** 5489: ** <ul> 5490: ** <li> The soft heap limit is set to zero. 5491: ** <li> Memory accounting is disabled using a combination of the 5492: ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5493: ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5494: ** <li> An alternative page cache implementation is specified using 5495: ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5496: ** <li> The page cache allocates from its own memory pool supplied 5497: ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5498: ** from the heap. 5499: ** </ul>)^ 5500: ** 5501: ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5502: ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5503: ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5504: ** the soft heap limit is enforced on every memory allocation. Without 5505: ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5506: ** when memory is allocated by the page cache. Testing suggests that because 5507: ** the page cache is the predominate memory user in SQLite, most 5508: ** applications will achieve adequate soft heap limit enforcement without 5509: ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5510: ** 5511: ** The circumstances under which SQLite will enforce the soft heap limit may 5512: ** changes in future releases of SQLite. 5513: */ 5514: SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5515: 5516: /* 5517: ** CAPI3REF: Deprecated Soft Heap Limit Interface 5518: ** DEPRECATED 5519: ** 5520: ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5521: ** interface. This routine is provided for historical compatibility 5522: ** only. All new applications should use the 5523: ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5524: */ 5525: SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5526: 5527: 5528: /* 5529: ** CAPI3REF: Extract Metadata About A Column Of A Table 5530: ** METHOD: sqlite3 5531: ** 5532: ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5533: ** information about column C of table T in database D 5534: ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5535: ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5536: ** the final five arguments with appropriate values if the specified 5537: ** column exists. ^The sqlite3_table_column_metadata() interface returns 5538: ** SQLITE_ERROR and if the specified column does not exist. 5539: ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5540: ** NULL pointer, then this routine simply checks for the existence of the 5541: ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5542: ** does not. 5543: ** 5544: ** ^The column is identified by the second, third and fourth parameters to 5545: ** this function. ^(The second parameter is either the name of the database 5546: ** (i.e. "main", "temp", or an attached database) containing the specified 5547: ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5548: ** for the table using the same algorithm used by the database engine to 5549: ** resolve unqualified table references. 5550: ** 5551: ** ^The third and fourth parameters to this function are the table and column 5552: ** name of the desired column, respectively. 5553: ** 5554: ** ^Metadata is returned by writing to the memory locations passed as the 5th 5555: ** and subsequent parameters to this function. ^Any of these arguments may be 5556: ** NULL, in which case the corresponding element of metadata is omitted. 5557: ** 5558: ** ^(<blockquote> 5559: ** <table border="1"> 5560: ** <tr><th> Parameter <th> Output<br>Type <th> Description 5561: ** 5562: ** <tr><td> 5th <td> const char* <td> Data type 5563: ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5564: ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5565: ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5566: ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5567: ** </table> 5568: ** </blockquote>)^ 5569: ** 5570: ** ^The memory pointed to by the character pointers returned for the 5571: ** declaration type and collation sequence is valid until the next 5572: ** call to any SQLite API function. 5573: ** 5574: ** ^If the specified table is actually a view, an [error code] is returned. 5575: ** 5576: ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5577: ** is not a [WITHOUT ROWID] table and an 5578: ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5579: ** parameters are set for the explicitly declared column. ^(If there is no 5580: ** [INTEGER PRIMARY KEY] column, then the outputs 5581: ** for the [rowid] are set as follows: 5582: ** 5583: ** <pre> 5584: ** data type: "INTEGER" 5585: ** collation sequence: "BINARY" 5586: ** not null: 0 5587: ** primary key: 1 5588: ** auto increment: 0 5589: ** </pre>)^ 5590: ** 5591: ** ^This function causes all database schemas to be read from disk and 5592: ** parsed, if that has not already been done, and returns an error if 5593: ** any errors are encountered while loading the schema. 5594: */ 5595: SQLITE_API int sqlite3_table_column_metadata( 5596: sqlite3 *db, /* Connection handle */ 5597: const char *zDbName, /* Database name or NULL */ 5598: const char *zTableName, /* Table name */ 5599: const char *zColumnName, /* Column name */ 5600: char const **pzDataType, /* OUTPUT: Declared data type */ 5601: char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5602: int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5603: int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5604: int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5605: ); 5606: 5607: /* 5608: ** CAPI3REF: Load An Extension 5609: ** METHOD: sqlite3 5610: ** 5611: ** ^This interface loads an SQLite extension library from the named file. 5612: ** 5613: ** ^The sqlite3_load_extension() interface attempts to load an 5614: ** [SQLite extension] library contained in the file zFile. If 5615: ** the file cannot be loaded directly, attempts are made to load 5616: ** with various operating-system specific extensions added. 5617: ** So for example, if "samplelib" cannot be loaded, then names like 5618: ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5619: ** be tried also. 5620: ** 5621: ** ^The entry point is zProc. 5622: ** ^(zProc may be 0, in which case SQLite will try to come up with an 5623: ** entry point name on its own. It first tries "sqlite3_extension_init". 5624: ** If that does not work, it constructs a name "sqlite3_X_init" where the 5625: ** X is consists of the lower-case equivalent of all ASCII alphabetic 5626: ** characters in the filename from the last "/" to the first following 5627: ** "." and omitting any initial "lib".)^ 5628: ** ^The sqlite3_load_extension() interface returns 5629: ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5630: ** ^If an error occurs and pzErrMsg is not 0, then the 5631: ** [sqlite3_load_extension()] interface shall attempt to 5632: ** fill *pzErrMsg with error message text stored in memory 5633: ** obtained from [sqlite3_malloc()]. The calling function 5634: ** should free this memory by calling [sqlite3_free()]. 5635: ** 5636: ** ^Extension loading must be enabled using 5637: ** [sqlite3_enable_load_extension()] or 5638: ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5639: ** prior to calling this API, 5640: ** otherwise an error will be returned. 5641: ** 5642: ** <b>Security warning:</b> It is recommended that the 5643: ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5644: ** interface. The use of the [sqlite3_enable_load_extension()] interface 5645: ** should be avoided. This will keep the SQL function [load_extension()] 5646: ** disabled and prevent SQL injections from giving attackers 5647: ** access to extension loading capabilities. 5648: ** 5649: ** See also the [load_extension() SQL function]. 5650: */ 5651: SQLITE_API int sqlite3_load_extension( 5652: sqlite3 *db, /* Load the extension into this database connection */ 5653: const char *zFile, /* Name of the shared library containing extension */ 5654: const char *zProc, /* Entry point. Derived from zFile if 0 */ 5655: char **pzErrMsg /* Put error message here if not 0 */ 5656: ); 5657: 5658: /* 5659: ** CAPI3REF: Enable Or Disable Extension Loading 5660: ** METHOD: sqlite3 5661: ** 5662: ** ^So as not to open security holes in older applications that are 5663: ** unprepared to deal with [extension loading], and as a means of disabling 5664: ** [extension loading] while evaluating user-entered SQL, the following API 5665: ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5666: ** 5667: ** ^Extension loading is off by default. 5668: ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5669: ** to turn extension loading on and call it with onoff==0 to turn 5670: ** it back off again. 5671: ** 5672: ** ^This interface enables or disables both the C-API 5673: ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5674: ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5675: ** to enable or disable only the C-API.)^ 5676: ** 5677: ** <b>Security warning:</b> It is recommended that extension loading 5678: ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5679: ** rather than this interface, so the [load_extension()] SQL function 5680: ** remains disabled. This will prevent SQL injections from giving attackers 5681: ** access to extension loading capabilities. 5682: */ 5683: SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5684: 5685: /* 5686: ** CAPI3REF: Automatically Load Statically Linked Extensions 5687: ** 5688: ** ^This interface causes the xEntryPoint() function to be invoked for 5689: ** each new [database connection] that is created. The idea here is that 5690: ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5691: ** that is to be automatically loaded into all new database connections. 5692: ** 5693: ** ^(Even though the function prototype shows that xEntryPoint() takes 5694: ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5695: ** arguments and expects an integer result as if the signature of the 5696: ** entry point where as follows: 5697: ** 5698: ** <blockquote><pre> 5699: **   int xEntryPoint( 5700: **   sqlite3 *db, 5701: **   const char **pzErrMsg, 5702: **   const struct sqlite3_api_routines *pThunk 5703: **   ); 5704: ** </pre></blockquote>)^ 5705: ** 5706: ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5707: ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5708: ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5709: ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5710: ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5711: ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5712: ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5713: ** 5714: ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5715: ** on the list of automatic extensions is a harmless no-op. ^No entry point 5716: ** will be called more than once for each database connection that is opened. 5717: ** 5718: ** See also: [sqlite3_reset_auto_extension()] 5719: ** and [sqlite3_cancel_auto_extension()] 5720: */ 5721: SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 5722: 5723: /* 5724: ** CAPI3REF: Cancel Automatic Extension Loading 5725: ** 5726: ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5727: ** initialization routine X that was registered using a prior call to 5728: ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5729: ** routine returns 1 if initialization routine X was successfully 5730: ** unregistered and it returns 0 if X was not on the list of initialization 5731: ** routines. 5732: */ 5733: SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 5734: 5735: /* 5736: ** CAPI3REF: Reset Automatic Extension Loading 5737: ** 5738: ** ^This interface disables all automatic extensions previously 5739: ** registered using [sqlite3_auto_extension()]. 5740: */ 5741: SQLITE_API void sqlite3_reset_auto_extension(void); 5742: 5743: /* 5744: ** The interface to the virtual-table mechanism is currently considered 5745: ** to be experimental. The interface might change in incompatible ways. 5746: ** If this is a problem for you, do not use the interface at this time. 5747: ** 5748: ** When the virtual-table mechanism stabilizes, we will declare the 5749: ** interface fixed, support it indefinitely, and remove this comment. 5750: */ 5751: 5752: /* 5753: ** Structures used by the virtual table interface 5754: */ 5755: typedef struct sqlite3_vtab sqlite3_vtab; 5756: typedef struct sqlite3_index_info sqlite3_index_info; 5757: typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5758: typedef struct sqlite3_module sqlite3_module; 5759: 5760: /* 5761: ** CAPI3REF: Virtual Table Object 5762: ** KEYWORDS: sqlite3_module {virtual table module} 5763: ** 5764: ** This structure, sometimes called a "virtual table module", 5765: ** defines the implementation of a [virtual tables]. 5766: ** This structure consists mostly of methods for the module. 5767: ** 5768: ** ^A virtual table module is created by filling in a persistent 5769: ** instance of this structure and passing a pointer to that instance 5770: ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5771: ** ^The registration remains valid until it is replaced by a different 5772: ** module or until the [database connection] closes. The content 5773: ** of this structure must not change while it is registered with 5774: ** any database connection. 5775: */ 5776: struct sqlite3_module { 5777: int iVersion; 5778: int (*xCreate)(sqlite3*, void *pAux, 5779: int argc, const char *const*argv, 5780: sqlite3_vtab **ppVTab, char**); 5781: int (*xConnect)(sqlite3*, void *pAux, 5782: int argc, const char *const*argv, 5783: sqlite3_vtab **ppVTab, char**); 5784: int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5785: int (*xDisconnect)(sqlite3_vtab *pVTab); 5786: int (*xDestroy)(sqlite3_vtab *pVTab); 5787: int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5788: int (*xClose)(sqlite3_vtab_cursor*); 5789: int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5790: int argc, sqlite3_value **argv); 5791: int (*xNext)(sqlite3_vtab_cursor*); 5792: int (*xEof)(sqlite3_vtab_cursor*); 5793: int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5794: int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5795: int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5796: int (*xBegin)(sqlite3_vtab *pVTab); 5797: int (*xSync)(sqlite3_vtab *pVTab); 5798: int (*xCommit)(sqlite3_vtab *pVTab); 5799: int (*xRollback)(sqlite3_vtab *pVTab); 5800: int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5801: void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5802: void **ppArg); 5803: int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5804: /* The methods above are in version 1 of the sqlite_module object. Those 5805: ** below are for version 2 and greater. */ 5806: int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5807: int (*xRelease)(sqlite3_vtab *pVTab, int); 5808: int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5809: }; 5810: 5811: /* 5812: ** CAPI3REF: Virtual Table Indexing Information 5813: ** KEYWORDS: sqlite3_index_info 5814: ** 5815: ** The sqlite3_index_info structure and its substructures is used as part 5816: ** of the [virtual table] interface to 5817: ** pass information into and receive the reply from the [xBestIndex] 5818: ** method of a [virtual table module]. The fields under **Inputs** are the 5819: ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5820: ** results into the **Outputs** fields. 5821: ** 5822: ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5823: ** 5824: ** <blockquote>column OP expr</blockquote> 5825: ** 5826: ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5827: ** stored in aConstraint[].op using one of the 5828: ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5829: ** ^(The index of the column is stored in 5830: ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5831: ** expr on the right-hand side can be evaluated (and thus the constraint 5832: ** is usable) and false if it cannot.)^ 5833: ** 5834: ** ^The optimizer automatically inverts terms of the form "expr OP column" 5835: ** and makes other simplifications to the WHERE clause in an attempt to 5836: ** get as many WHERE clause terms into the form shown above as possible. 5837: ** ^The aConstraint[] array only reports WHERE clause terms that are 5838: ** relevant to the particular virtual table being queried. 5839: ** 5840: ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5841: ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5842: ** 5843: ** The colUsed field indicates which columns of the virtual table may be 5844: ** required by the current scan. Virtual table columns are numbered from 5845: ** zero in the order in which they appear within the CREATE TABLE statement 5846: ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5847: ** the corresponding bit is set within the colUsed mask if the column may be 5848: ** required by SQLite. If the table has at least 64 columns and any column 5849: ** to the right of the first 63 is required, then bit 63 of colUsed is also 5850: ** set. In other words, column iCol may be required if the expression 5851: ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5852: ** non-zero. 5853: ** 5854: ** The [xBestIndex] method must fill aConstraintUsage[] with information 5855: ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5856: ** the right-hand side of the corresponding aConstraint[] is evaluated 5857: ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5858: ** is true, then the constraint is assumed to be fully handled by the 5859: ** virtual table and is not checked again by SQLite.)^ 5860: ** 5861: ** ^The idxNum and idxPtr values are recorded and passed into the 5862: ** [xFilter] method. 5863: ** ^[sqlite3_free()] is used to free idxPtr if and only if 5864: ** needToFreeIdxPtr is true. 5865: ** 5866: ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5867: ** the correct order to satisfy the ORDER BY clause so that no separate 5868: ** sorting step is required. 5869: ** 5870: ** ^The estimatedCost value is an estimate of the cost of a particular 5871: ** strategy. A cost of N indicates that the cost of the strategy is similar 5872: ** to a linear scan of an SQLite table with N rows. A cost of log(N) 5873: ** indicates that the expense of the operation is similar to that of a 5874: ** binary search on a unique indexed field of an SQLite table with N rows. 5875: ** 5876: ** ^The estimatedRows value is an estimate of the number of rows that 5877: ** will be returned by the strategy. 5878: ** 5879: ** The xBestIndex method may optionally populate the idxFlags field with a 5880: ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5881: ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5882: ** assumes that the strategy may visit at most one row. 5883: ** 5884: ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5885: ** SQLite also assumes that if a call to the xUpdate() method is made as 5886: ** part of the same statement to delete or update a virtual table row and the 5887: ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5888: ** any database changes. In other words, if the xUpdate() returns 5889: ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5890: ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5891: ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5892: ** the xUpdate method are automatically rolled back by SQLite. 5893: ** 5894: ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5895: ** structure for SQLite version 3.8.2. If a virtual table extension is 5896: ** used with an SQLite version earlier than 3.8.2, the results of attempting 5897: ** to read or write the estimatedRows field are undefined (but are likely 5898: ** to included crashing the application). The estimatedRows field should 5899: ** therefore only be used if [sqlite3_libversion_number()] returns a 5900: ** value greater than or equal to 3008002. Similarly, the idxFlags field 5901: ** was added for version 3.9.0. It may therefore only be used if 5902: ** sqlite3_libversion_number() returns a value greater than or equal to 5903: ** 3009000. 5904: */ 5905: struct sqlite3_index_info { 5906: /* Inputs */ 5907: int nConstraint; /* Number of entries in aConstraint */ 5908: struct sqlite3_index_constraint { 5909: int iColumn; /* Column constrained. -1 for ROWID */ 5910: unsigned char op; /* Constraint operator */ 5911: unsigned char usable; /* True if this constraint is usable */ 5912: int iTermOffset; /* Used internally - xBestIndex should ignore */ 5913: } *aConstraint; /* Table of WHERE clause constraints */ 5914: int nOrderBy; /* Number of terms in the ORDER BY clause */ 5915: struct sqlite3_index_orderby { 5916: int iColumn; /* Column number */ 5917: unsigned char desc; /* True for DESC. False for ASC. */ 5918: } *aOrderBy; /* The ORDER BY clause */ 5919: /* Outputs */ 5920: struct sqlite3_index_constraint_usage { 5921: int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5922: unsigned char omit; /* Do not code a test for this constraint */ 5923: } *aConstraintUsage; 5924: int idxNum; /* Number used to identify the index */ 5925: char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5926: int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5927: int orderByConsumed; /* True if output is already ordered */ 5928: double estimatedCost; /* Estimated cost of using this index */ 5929: /* Fields below are only available in SQLite 3.8.2 and later */ 5930: sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5931: /* Fields below are only available in SQLite 3.9.0 and later */ 5932: int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 5933: /* Fields below are only available in SQLite 3.10.0 and later */ 5934: sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 5935: }; 5936: 5937: /* 5938: ** CAPI3REF: Virtual Table Scan Flags 5939: */ 5940: #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 5941: 5942: /* 5943: ** CAPI3REF: Virtual Table Constraint Operator Codes 5944: ** 5945: ** These macros defined the allowed values for the 5946: ** [sqlite3_index_info].aConstraint[].op field. Each value represents 5947: ** an operator that is part of a constraint term in the wHERE clause of 5948: ** a query that uses a [virtual table]. 5949: */ 5950: #define SQLITE_INDEX_CONSTRAINT_EQ 2 5951: #define SQLITE_INDEX_CONSTRAINT_GT 4 5952: #define SQLITE_INDEX_CONSTRAINT_LE 8 5953: #define SQLITE_INDEX_CONSTRAINT_LT 16 5954: #define SQLITE_INDEX_CONSTRAINT_GE 32 5955: #define SQLITE_INDEX_CONSTRAINT_MATCH 64 5956: #define SQLITE_INDEX_CONSTRAINT_LIKE 65 5957: #define SQLITE_INDEX_CONSTRAINT_GLOB 66 5958: #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 5959: 5960: /* 5961: ** CAPI3REF: Register A Virtual Table Implementation 5962: ** METHOD: sqlite3 5963: ** 5964: ** ^These routines are used to register a new [virtual table module] name. 5965: ** ^Module names must be registered before 5966: ** creating a new [virtual table] using the module and before using a 5967: ** preexisting [virtual table] for the module. 5968: ** 5969: ** ^The module name is registered on the [database connection] specified 5970: ** by the first parameter. ^The name of the module is given by the 5971: ** second parameter. ^The third parameter is a pointer to 5972: ** the implementation of the [virtual table module]. ^The fourth 5973: ** parameter is an arbitrary client data pointer that is passed through 5974: ** into the [xCreate] and [xConnect] methods of the virtual table module 5975: ** when a new virtual table is be being created or reinitialized. 5976: ** 5977: ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5978: ** is a pointer to a destructor for the pClientData. ^SQLite will 5979: ** invoke the destructor function (if it is not NULL) when SQLite 5980: ** no longer needs the pClientData pointer. ^The destructor will also 5981: ** be invoked if the call to sqlite3_create_module_v2() fails. 5982: ** ^The sqlite3_create_module() 5983: ** interface is equivalent to sqlite3_create_module_v2() with a NULL 5984: ** destructor. 5985: */ 5986: SQLITE_API int sqlite3_create_module( 5987: sqlite3 *db, /* SQLite connection to register module with */ 5988: const char *zName, /* Name of the module */ 5989: const sqlite3_module *p, /* Methods for the module */ 5990: void *pClientData /* Client data for xCreate/xConnect */ 5991: ); 5992: SQLITE_API int sqlite3_create_module_v2( 5993: sqlite3 *db, /* SQLite connection to register module with */ 5994: const char *zName, /* Name of the module */ 5995: const sqlite3_module *p, /* Methods for the module */ 5996: void *pClientData, /* Client data for xCreate/xConnect */ 5997: void(*xDestroy)(void*) /* Module destructor function */ 5998: ); 5999: 6000: /* 6001: ** CAPI3REF: Virtual Table Instance Object 6002: ** KEYWORDS: sqlite3_vtab 6003: ** 6004: ** Every [virtual table module] implementation uses a subclass 6005: ** of this object to describe a particular instance 6006: ** of the [virtual table]. Each subclass will 6007: ** be tailored to the specific needs of the module implementation. 6008: ** The purpose of this superclass is to define certain fields that are 6009: ** common to all module implementations. 6010: ** 6011: ** ^Virtual tables methods can set an error message by assigning a 6012: ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6013: ** take care that any prior string is freed by a call to [sqlite3_free()] 6014: ** prior to assigning a new string to zErrMsg. ^After the error message 6015: ** is delivered up to the client application, the string will be automatically 6016: ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6017: */ 6018: struct sqlite3_vtab { 6019: const sqlite3_module *pModule; /* The module for this virtual table */ 6020: int nRef; /* Number of open cursors */ 6021: char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6022: /* Virtual table implementations will typically add additional fields */ 6023: }; 6024: 6025: /* 6026: ** CAPI3REF: Virtual Table Cursor Object 6027: ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6028: ** 6029: ** Every [virtual table module] implementation uses a subclass of the 6030: ** following structure to describe cursors that point into the 6031: ** [virtual table] and are used 6032: ** to loop through the virtual table. Cursors are created using the 6033: ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6034: ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6035: ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6036: ** of the module. Each module implementation will define 6037: ** the content of a cursor structure to suit its own needs. 6038: ** 6039: ** This superclass exists in order to define fields of the cursor that 6040: ** are common to all implementations. 6041: */ 6042: struct sqlite3_vtab_cursor { 6043: sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6044: /* Virtual table implementations will typically add additional fields */ 6045: }; 6046: 6047: /* 6048: ** CAPI3REF: Declare The Schema Of A Virtual Table 6049: ** 6050: ** ^The [xCreate] and [xConnect] methods of a 6051: ** [virtual table module] call this interface 6052: ** to declare the format (the names and datatypes of the columns) of 6053: ** the virtual tables they implement. 6054: */ 6055: SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6056: 6057: /* 6058: ** CAPI3REF: Overload A Function For A Virtual Table 6059: ** METHOD: sqlite3 6060: ** 6061: ** ^(Virtual tables can provide alternative implementations of functions 6062: ** using the [xFindFunction] method of the [virtual table module]. 6063: ** But global versions of those functions 6064: ** must exist in order to be overloaded.)^ 6065: ** 6066: ** ^(This API makes sure a global version of a function with a particular 6067: ** name and number of parameters exists. If no such function exists 6068: ** before this API is called, a new function is created.)^ ^The implementation 6069: ** of the new function always causes an exception to be thrown. So 6070: ** the new function is not good for anything by itself. Its only 6071: ** purpose is to be a placeholder function that can be overloaded 6072: ** by a [virtual table]. 6073: */ 6074: SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6075: 6076: /* 6077: ** The interface to the virtual-table mechanism defined above (back up 6078: ** to a comment remarkably similar to this one) is currently considered 6079: ** to be experimental. The interface might change in incompatible ways. 6080: ** If this is a problem for you, do not use the interface at this time. 6081: ** 6082: ** When the virtual-table mechanism stabilizes, we will declare the 6083: ** interface fixed, support it indefinitely, and remove this comment. 6084: */ 6085: 6086: /* 6087: ** CAPI3REF: A Handle To An Open BLOB 6088: ** KEYWORDS: {BLOB handle} {BLOB handles} 6089: ** 6090: ** An instance of this object represents an open BLOB on which 6091: ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6092: ** ^Objects of this type are created by [sqlite3_blob_open()] 6093: ** and destroyed by [sqlite3_blob_close()]. 6094: ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6095: ** can be used to read or write small subsections of the BLOB. 6096: ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6097: */ 6098: typedef struct sqlite3_blob sqlite3_blob; 6099: 6100: /* 6101: ** CAPI3REF: Open A BLOB For Incremental I/O 6102: ** METHOD: sqlite3 6103: ** CONSTRUCTOR: sqlite3_blob 6104: ** 6105: ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6106: ** in row iRow, column zColumn, table zTable in database zDb; 6107: ** in other words, the same BLOB that would be selected by: 6108: ** 6109: ** <pre> 6110: ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6111: ** </pre>)^ 6112: ** 6113: ** ^(Parameter zDb is not the filename that contains the database, but 6114: ** rather the symbolic name of the database. For attached databases, this is 6115: ** the name that appears after the AS keyword in the [ATTACH] statement. 6116: ** For the main database file, the database name is "main". For TEMP 6117: ** tables, the database name is "temp".)^ 6118: ** 6119: ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6120: ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6121: ** read-only access. 6122: ** 6123: ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6124: ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6125: ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6126: ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6127: ** on *ppBlob after this function it returns. 6128: ** 6129: ** This function fails with SQLITE_ERROR if any of the following are true: 6130: ** <ul> 6131: ** <li> ^(Database zDb does not exist)^, 6132: ** <li> ^(Table zTable does not exist within database zDb)^, 6133: ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6134: ** <li> ^(Column zColumn does not exist)^, 6135: ** <li> ^(Row iRow is not present in the table)^, 6136: ** <li> ^(The specified column of row iRow contains a value that is not 6137: ** a TEXT or BLOB value)^, 6138: ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6139: ** constraint and the blob is being opened for read/write access)^, 6140: ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6141: ** column zColumn is part of a [child key] definition and the blob is 6142: ** being opened for read/write access)^. 6143: ** </ul> 6144: ** 6145: ** ^Unless it returns SQLITE_MISUSE, this function sets the 6146: ** [database connection] error code and message accessible via 6147: ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6148: ** 6149: ** 6150: ** ^(If the row that a BLOB handle points to is modified by an 6151: ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6152: ** then the BLOB handle is marked as "expired". 6153: ** This is true if any column of the row is changed, even a column 6154: ** other than the one the BLOB handle is open on.)^ 6155: ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6156: ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6157: ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6158: ** rolled back by the expiration of the BLOB. Such changes will eventually 6159: ** commit if the transaction continues to completion.)^ 6160: ** 6161: ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6162: ** the opened blob. ^The size of a blob may not be changed by this 6163: ** interface. Use the [UPDATE] SQL command to change the size of a 6164: ** blob. 6165: ** 6166: ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6167: ** and the built-in [zeroblob] SQL function may be used to create a 6168: ** zero-filled blob to read or write using the incremental-blob interface. 6169: ** 6170: ** To avoid a resource leak, every open [BLOB handle] should eventually 6171: ** be released by a call to [sqlite3_blob_close()]. 6172: */ 6173: SQLITE_API int sqlite3_blob_open( 6174: sqlite3*, 6175: const char *zDb, 6176: const char *zTable, 6177: const char *zColumn, 6178: sqlite3_int64 iRow, 6179: int flags, 6180: sqlite3_blob **ppBlob 6181: ); 6182: 6183: /* 6184: ** CAPI3REF: Move a BLOB Handle to a New Row 6185: ** METHOD: sqlite3_blob 6186: ** 6187: ** ^This function is used to move an existing blob handle so that it points 6188: ** to a different row of the same database table. ^The new row is identified 6189: ** by the rowid value passed as the second argument. Only the row can be 6190: ** changed. ^The database, table and column on which the blob handle is open 6191: ** remain the same. Moving an existing blob handle to a new row can be 6192: ** faster than closing the existing handle and opening a new one. 6193: ** 6194: ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6195: ** it must exist and there must be either a blob or text value stored in 6196: ** the nominated column.)^ ^If the new row is not present in the table, or if 6197: ** it does not contain a blob or text value, or if another error occurs, an 6198: ** SQLite error code is returned and the blob handle is considered aborted. 6199: ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6200: ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6201: ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6202: ** always returns zero. 6203: ** 6204: ** ^This function sets the database handle error code and message. 6205: */ 6206: SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6207: 6208: /* 6209: ** CAPI3REF: Close A BLOB Handle 6210: ** DESTRUCTOR: sqlite3_blob 6211: ** 6212: ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6213: ** unconditionally. Even if this routine returns an error code, the 6214: ** handle is still closed.)^ 6215: ** 6216: ** ^If the blob handle being closed was opened for read-write access, and if 6217: ** the database is in auto-commit mode and there are no other open read-write 6218: ** blob handles or active write statements, the current transaction is 6219: ** committed. ^If an error occurs while committing the transaction, an error 6220: ** code is returned and the transaction rolled back. 6221: ** 6222: ** Calling this function with an argument that is not a NULL pointer or an 6223: ** open blob handle results in undefined behaviour. ^Calling this routine 6224: ** with a null pointer (such as would be returned by a failed call to 6225: ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6226: ** is passed a valid open blob handle, the values returned by the 6227: ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6228: */ 6229: SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6230: 6231: /* 6232: ** CAPI3REF: Return The Size Of An Open BLOB 6233: ** METHOD: sqlite3_blob 6234: ** 6235: ** ^Returns the size in bytes of the BLOB accessible via the 6236: ** successfully opened [BLOB handle] in its only argument. ^The 6237: ** incremental blob I/O routines can only read or overwriting existing 6238: ** blob content; they cannot change the size of a blob. 6239: ** 6240: ** This routine only works on a [BLOB handle] which has been created 6241: ** by a prior successful call to [sqlite3_blob_open()] and which has not 6242: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6243: ** to this routine results in undefined and probably undesirable behavior. 6244: */ 6245: SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6246: 6247: /* 6248: ** CAPI3REF: Read Data From A BLOB Incrementally 6249: ** METHOD: sqlite3_blob 6250: ** 6251: ** ^(This function is used to read data from an open [BLOB handle] into a 6252: ** caller-supplied buffer. N bytes of data are copied into buffer Z 6253: ** from the open BLOB, starting at offset iOffset.)^ 6254: ** 6255: ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6256: ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6257: ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6258: ** ^The size of the blob (and hence the maximum value of N+iOffset) 6259: ** can be determined using the [sqlite3_blob_bytes()] interface. 6260: ** 6261: ** ^An attempt to read from an expired [BLOB handle] fails with an 6262: ** error code of [SQLITE_ABORT]. 6263: ** 6264: ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6265: ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6266: ** 6267: ** This routine only works on a [BLOB handle] which has been created 6268: ** by a prior successful call to [sqlite3_blob_open()] and which has not 6269: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6270: ** to this routine results in undefined and probably undesirable behavior. 6271: ** 6272: ** See also: [sqlite3_blob_write()]. 6273: */ 6274: SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6275: 6276: /* 6277: ** CAPI3REF: Write Data Into A BLOB Incrementally 6278: ** METHOD: sqlite3_blob 6279: ** 6280: ** ^(This function is used to write data into an open [BLOB handle] from a 6281: ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6282: ** into the open BLOB, starting at offset iOffset.)^ 6283: ** 6284: ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6285: ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6286: ** ^Unless SQLITE_MISUSE is returned, this function sets the 6287: ** [database connection] error code and message accessible via 6288: ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6289: ** 6290: ** ^If the [BLOB handle] passed as the first argument was not opened for 6291: ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6292: ** this function returns [SQLITE_READONLY]. 6293: ** 6294: ** This function may only modify the contents of the BLOB; it is 6295: ** not possible to increase the size of a BLOB using this API. 6296: ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6297: ** [SQLITE_ERROR] is returned and no data is written. The size of the 6298: ** BLOB (and hence the maximum value of N+iOffset) can be determined 6299: ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6300: ** than zero [SQLITE_ERROR] is returned and no data is written. 6301: ** 6302: ** ^An attempt to write to an expired [BLOB handle] fails with an 6303: ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6304: ** before the [BLOB handle] expired are not rolled back by the 6305: ** expiration of the handle, though of course those changes might 6306: ** have been overwritten by the statement that expired the BLOB handle 6307: ** or by other independent statements. 6308: ** 6309: ** This routine only works on a [BLOB handle] which has been created 6310: ** by a prior successful call to [sqlite3_blob_open()] and which has not 6311: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6312: ** to this routine results in undefined and probably undesirable behavior. 6313: ** 6314: ** See also: [sqlite3_blob_read()]. 6315: */ 6316: SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6317: 6318: /* 6319: ** CAPI3REF: Virtual File System Objects 6320: ** 6321: ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6322: ** that SQLite uses to interact 6323: ** with the underlying operating system. Most SQLite builds come with a 6324: ** single default VFS that is appropriate for the host computer. 6325: ** New VFSes can be registered and existing VFSes can be unregistered. 6326: ** The following interfaces are provided. 6327: ** 6328: ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6329: ** ^Names are case sensitive. 6330: ** ^Names are zero-terminated UTF-8 strings. 6331: ** ^If there is no match, a NULL pointer is returned. 6332: ** ^If zVfsName is NULL then the default VFS is returned. 6333: ** 6334: ** ^New VFSes are registered with sqlite3_vfs_register(). 6335: ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6336: ** ^The same VFS can be registered multiple times without injury. 6337: ** ^To make an existing VFS into the default VFS, register it again 6338: ** with the makeDflt flag set. If two different VFSes with the 6339: ** same name are registered, the behavior is undefined. If a 6340: ** VFS is registered with a name that is NULL or an empty string, 6341: ** then the behavior is undefined. 6342: ** 6343: ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6344: ** ^(If the default VFS is unregistered, another VFS is chosen as 6345: ** the default. The choice for the new VFS is arbitrary.)^ 6346: */ 6347: SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6348: SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6349: SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6350: 6351: /* 6352: ** CAPI3REF: Mutexes 6353: ** 6354: ** The SQLite core uses these routines for thread 6355: ** synchronization. Though they are intended for internal 6356: ** use by SQLite, code that links against SQLite is 6357: ** permitted to use any of these routines. 6358: ** 6359: ** The SQLite source code contains multiple implementations 6360: ** of these mutex routines. An appropriate implementation 6361: ** is selected automatically at compile-time. The following 6362: ** implementations are available in the SQLite core: 6363: ** 6364: ** <ul> 6365: ** <li> SQLITE_MUTEX_PTHREADS 6366: ** <li> SQLITE_MUTEX_W32 6367: ** <li> SQLITE_MUTEX_NOOP 6368: ** </ul> 6369: ** 6370: ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6371: ** that does no real locking and is appropriate for use in 6372: ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6373: ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6374: ** and Windows. 6375: ** 6376: ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6377: ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6378: ** implementation is included with the library. In this case the 6379: ** application must supply a custom mutex implementation using the 6380: ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6381: ** before calling sqlite3_initialize() or any other public sqlite3_ 6382: ** function that calls sqlite3_initialize(). 6383: ** 6384: ** ^The sqlite3_mutex_alloc() routine allocates a new 6385: ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6386: ** routine returns NULL if it is unable to allocate the requested 6387: ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6388: ** integer constants: 6389: ** 6390: ** <ul> 6391: ** <li> SQLITE_MUTEX_FAST 6392: ** <li> SQLITE_MUTEX_RECURSIVE 6393: ** <li> SQLITE_MUTEX_STATIC_MASTER 6394: ** <li> SQLITE_MUTEX_STATIC_MEM 6395: ** <li> SQLITE_MUTEX_STATIC_OPEN 6396: ** <li> SQLITE_MUTEX_STATIC_PRNG 6397: ** <li> SQLITE_MUTEX_STATIC_LRU 6398: ** <li> SQLITE_MUTEX_STATIC_PMEM 6399: ** <li> SQLITE_MUTEX_STATIC_APP1 6400: ** <li> SQLITE_MUTEX_STATIC_APP2 6401: ** <li> SQLITE_MUTEX_STATIC_APP3 6402: ** <li> SQLITE_MUTEX_STATIC_VFS1 6403: ** <li> SQLITE_MUTEX_STATIC_VFS2 6404: ** <li> SQLITE_MUTEX_STATIC_VFS3 6405: ** </ul> 6406: ** 6407: ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6408: ** cause sqlite3_mutex_alloc() to create 6409: ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6410: ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6411: ** The mutex implementation does not need to make a distinction 6412: ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6413: ** not want to. SQLite will only request a recursive mutex in 6414: ** cases where it really needs one. If a faster non-recursive mutex 6415: ** implementation is available on the host platform, the mutex subsystem 6416: ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6417: ** 6418: ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6419: ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6420: ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6421: ** used by the current version of SQLite. Future versions of SQLite 6422: ** may add additional static mutexes. Static mutexes are for internal 6423: ** use by SQLite only. Applications that use SQLite mutexes should 6424: ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6425: ** SQLITE_MUTEX_RECURSIVE. 6426: ** 6427: ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6428: ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6429: ** returns a different mutex on every call. ^For the static 6430: ** mutex types, the same mutex is returned on every call that has 6431: ** the same type number. 6432: ** 6433: ** ^The sqlite3_mutex_free() routine deallocates a previously 6434: ** allocated dynamic mutex. Attempting to deallocate a static 6435: ** mutex results in undefined behavior. 6436: ** 6437: ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6438: ** to enter a mutex. ^If another thread is already within the mutex, 6439: ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6440: ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6441: ** upon successful entry. ^(Mutexes created using 6442: ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6443: ** In such cases, the 6444: ** mutex must be exited an equal number of times before another thread 6445: ** can enter.)^ If the same thread tries to enter any mutex other 6446: ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6447: ** 6448: ** ^(Some systems (for example, Windows 95) do not support the operation 6449: ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6450: ** will always return SQLITE_BUSY. The SQLite core only ever uses 6451: ** sqlite3_mutex_try() as an optimization so this is acceptable 6452: ** behavior.)^ 6453: ** 6454: ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6455: ** previously entered by the same thread. The behavior 6456: ** is undefined if the mutex is not currently entered by the 6457: ** calling thread or is not currently allocated. 6458: ** 6459: ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6460: ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6461: ** behave as no-ops. 6462: ** 6463: ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6464: */ 6465: SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 6466: SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 6467: SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 6468: SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 6469: SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 6470: 6471: /* 6472: ** CAPI3REF: Mutex Methods Object 6473: ** 6474: ** An instance of this structure defines the low-level routines 6475: ** used to allocate and use mutexes. 6476: ** 6477: ** Usually, the default mutex implementations provided by SQLite are 6478: ** sufficient, however the application has the option of substituting a custom 6479: ** implementation for specialized deployments or systems for which SQLite 6480: ** does not provide a suitable implementation. In this case, the application 6481: ** creates and populates an instance of this structure to pass 6482: ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6483: ** Additionally, an instance of this structure can be used as an 6484: ** output variable when querying the system for the current mutex 6485: ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6486: ** 6487: ** ^The xMutexInit method defined by this structure is invoked as 6488: ** part of system initialization by the sqlite3_initialize() function. 6489: ** ^The xMutexInit routine is called by SQLite exactly once for each 6490: ** effective call to [sqlite3_initialize()]. 6491: ** 6492: ** ^The xMutexEnd method defined by this structure is invoked as 6493: ** part of system shutdown by the sqlite3_shutdown() function. The 6494: ** implementation of this method is expected to release all outstanding 6495: ** resources obtained by the mutex methods implementation, especially 6496: ** those obtained by the xMutexInit method. ^The xMutexEnd() 6497: ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6498: ** 6499: ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6500: ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6501: ** xMutexNotheld) implement the following interfaces (respectively): 6502: ** 6503: ** <ul> 6504: ** <li> [sqlite3_mutex_alloc()] </li> 6505: ** <li> [sqlite3_mutex_free()] </li> 6506: ** <li> [sqlite3_mutex_enter()] </li> 6507: ** <li> [sqlite3_mutex_try()] </li> 6508: ** <li> [sqlite3_mutex_leave()] </li> 6509: ** <li> [sqlite3_mutex_held()] </li> 6510: ** <li> [sqlite3_mutex_notheld()] </li> 6511: ** </ul>)^ 6512: ** 6513: ** The only difference is that the public sqlite3_XXX functions enumerated 6514: ** above silently ignore any invocations that pass a NULL pointer instead 6515: ** of a valid mutex handle. The implementations of the methods defined 6516: ** by this structure are not required to handle this case, the results 6517: ** of passing a NULL pointer instead of a valid mutex handle are undefined 6518: ** (i.e. it is acceptable to provide an implementation that segfaults if 6519: ** it is passed a NULL pointer). 6520: ** 6521: ** The xMutexInit() method must be threadsafe. It must be harmless to 6522: ** invoke xMutexInit() multiple times within the same process and without 6523: ** intervening calls to xMutexEnd(). Second and subsequent calls to 6524: ** xMutexInit() must be no-ops. 6525: ** 6526: ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6527: ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6528: ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6529: ** memory allocation for a fast or recursive mutex. 6530: ** 6531: ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6532: ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6533: ** If xMutexInit fails in any way, it is expected to clean up after itself 6534: ** prior to returning. 6535: */ 6536: typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6537: struct sqlite3_mutex_methods { 6538: int (*xMutexInit)(void); 6539: int (*xMutexEnd)(void); 6540: sqlite3_mutex *(*xMutexAlloc)(int); 6541: void (*xMutexFree)(sqlite3_mutex *); 6542: void (*xMutexEnter)(sqlite3_mutex *); 6543: int (*xMutexTry)(sqlite3_mutex *); 6544: void (*xMutexLeave)(sqlite3_mutex *); 6545: int (*xMutexHeld)(sqlite3_mutex *); 6546: int (*xMutexNotheld)(sqlite3_mutex *); 6547: }; 6548: 6549: /* 6550: ** CAPI3REF: Mutex Verification Routines 6551: ** 6552: ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6553: ** are intended for use inside assert() statements. The SQLite core 6554: ** never uses these routines except inside an assert() and applications 6555: ** are advised to follow the lead of the core. The SQLite core only 6556: ** provides implementations for these routines when it is compiled 6557: ** with the SQLITE_DEBUG flag. External mutex implementations 6558: ** are only required to provide these routines if SQLITE_DEBUG is 6559: ** defined and if NDEBUG is not defined. 6560: ** 6561: ** These routines should return true if the mutex in their argument 6562: ** is held or not held, respectively, by the calling thread. 6563: ** 6564: ** The implementation is not required to provide versions of these 6565: ** routines that actually work. If the implementation does not provide working 6566: ** versions of these routines, it should at least provide stubs that always 6567: ** return true so that one does not get spurious assertion failures. 6568: ** 6569: ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6570: ** the routine should return 1. This seems counter-intuitive since 6571: ** clearly the mutex cannot be held if it does not exist. But 6572: ** the reason the mutex does not exist is because the build is not 6573: ** using mutexes. And we do not want the assert() containing the 6574: ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6575: ** the appropriate thing to do. The sqlite3_mutex_notheld() 6576: ** interface should also return 1 when given a NULL pointer. 6577: */ 6578: #ifndef NDEBUG 6579: SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 6580: SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 6581: #endif 6582: 6583: /* 6584: ** CAPI3REF: Mutex Types 6585: ** 6586: ** The [sqlite3_mutex_alloc()] interface takes a single argument 6587: ** which is one of these integer constants. 6588: ** 6589: ** The set of static mutexes may change from one SQLite release to the 6590: ** next. Applications that override the built-in mutex logic must be 6591: ** prepared to accommodate additional static mutexes. 6592: */ 6593: #define SQLITE_MUTEX_FAST 0 6594: #define SQLITE_MUTEX_RECURSIVE 1 6595: #define SQLITE_MUTEX_STATIC_MASTER 2 6596: #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6597: #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6598: #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6599: #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6600: #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6601: #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6602: #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6603: #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6604: #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6605: #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6606: #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6607: #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6608: #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6609: 6610: /* 6611: ** CAPI3REF: Retrieve the mutex for a database connection 6612: ** METHOD: sqlite3 6613: ** 6614: ** ^This interface returns a pointer the [sqlite3_mutex] object that 6615: ** serializes access to the [database connection] given in the argument 6616: ** when the [threading mode] is Serialized. 6617: ** ^If the [threading mode] is Single-thread or Multi-thread then this 6618: ** routine returns a NULL pointer. 6619: */ 6620: SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6621: 6622: /* 6623: ** CAPI3REF: Low-Level Control Of Database Files 6624: ** METHOD: sqlite3 6625: ** 6626: ** ^The [sqlite3_file_control()] interface makes a direct call to the 6627: ** xFileControl method for the [sqlite3_io_methods] object associated 6628: ** with a particular database identified by the second argument. ^The 6629: ** name of the database is "main" for the main database or "temp" for the 6630: ** TEMP database, or the name that appears after the AS keyword for 6631: ** databases that are added using the [ATTACH] SQL command. 6632: ** ^A NULL pointer can be used in place of "main" to refer to the 6633: ** main database file. 6634: ** ^The third and fourth parameters to this routine 6635: ** are passed directly through to the second and third parameters of 6636: ** the xFileControl method. ^The return value of the xFileControl 6637: ** method becomes the return value of this routine. 6638: ** 6639: ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6640: ** a pointer to the underlying [sqlite3_file] object to be written into 6641: ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6642: ** case is a short-circuit path which does not actually invoke the 6643: ** underlying sqlite3_io_methods.xFileControl method. 6644: ** 6645: ** ^If the second parameter (zDbName) does not match the name of any 6646: ** open database file, then SQLITE_ERROR is returned. ^This error 6647: ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6648: ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6649: ** also return SQLITE_ERROR. There is no way to distinguish between 6650: ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6651: ** xFileControl method. 6652: ** 6653: ** See also: [SQLITE_FCNTL_LOCKSTATE] 6654: */ 6655: SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6656: 6657: /* 6658: ** CAPI3REF: Testing Interface 6659: ** 6660: ** ^The sqlite3_test_control() interface is used to read out internal 6661: ** state of SQLite and to inject faults into SQLite for testing 6662: ** purposes. ^The first parameter is an operation code that determines 6663: ** the number, meaning, and operation of all subsequent parameters. 6664: ** 6665: ** This interface is not for use by applications. It exists solely 6666: ** for verifying the correct operation of the SQLite library. Depending 6667: ** on how the SQLite library is compiled, this interface might not exist. 6668: ** 6669: ** The details of the operation codes, their meanings, the parameters 6670: ** they take, and what they do are all subject to change without notice. 6671: ** Unlike most of the SQLite API, this function is not guaranteed to 6672: ** operate consistently from one release to the next. 6673: */ 6674: SQLITE_API int sqlite3_test_control(int op, ...); 6675: 6676: /* 6677: ** CAPI3REF: Testing Interface Operation Codes 6678: ** 6679: ** These constants are the valid operation code parameters used 6680: ** as the first argument to [sqlite3_test_control()]. 6681: ** 6682: ** These parameters and their meanings are subject to change 6683: ** without notice. These values are for testing purposes only. 6684: ** Applications should not use any of these parameters or the 6685: ** [sqlite3_test_control()] interface. 6686: */ 6687: #define SQLITE_TESTCTRL_FIRST 5 6688: #define SQLITE_TESTCTRL_PRNG_SAVE 5 6689: #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6690: #define SQLITE_TESTCTRL_PRNG_RESET 7 6691: #define SQLITE_TESTCTRL_BITVEC_TEST 8 6692: #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6693: #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6694: #define SQLITE_TESTCTRL_PENDING_BYTE 11 6695: #define SQLITE_TESTCTRL_ASSERT 12 6696: #define SQLITE_TESTCTRL_ALWAYS 13 6697: #define SQLITE_TESTCTRL_RESERVE 14 6698: #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6699: #define SQLITE_TESTCTRL_ISKEYWORD 16 6700: #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6701: #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6702: #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6703: #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6704: #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6705: #define SQLITE_TESTCTRL_BYTEORDER 22 6706: #define SQLITE_TESTCTRL_ISINIT 23 6707: #define SQLITE_TESTCTRL_SORTER_MMAP 24 6708: #define SQLITE_TESTCTRL_IMPOSTER 25 6709: #define SQLITE_TESTCTRL_LAST 25 6710: 6711: /* 6712: ** CAPI3REF: SQLite Runtime Status 6713: ** 6714: ** ^These interfaces are used to retrieve runtime status information 6715: ** about the performance of SQLite, and optionally to reset various 6716: ** highwater marks. ^The first argument is an integer code for 6717: ** the specific parameter to measure. ^(Recognized integer codes 6718: ** are of the form [status parameters | SQLITE_STATUS_...].)^ 6719: ** ^The current value of the parameter is returned into *pCurrent. 6720: ** ^The highest recorded value is returned in *pHighwater. ^If the 6721: ** resetFlag is true, then the highest record value is reset after 6722: ** *pHighwater is written. ^(Some parameters do not record the highest 6723: ** value. For those parameters 6724: ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6725: ** ^(Other parameters record only the highwater mark and not the current 6726: ** value. For these latter parameters nothing is written into *pCurrent.)^ 6727: ** 6728: ** ^The sqlite3_status() and sqlite3_status64() routines return 6729: ** SQLITE_OK on success and a non-zero [error code] on failure. 6730: ** 6731: ** If either the current value or the highwater mark is too large to 6732: ** be represented by a 32-bit integer, then the values returned by 6733: ** sqlite3_status() are undefined. 6734: ** 6735: ** See also: [sqlite3_db_status()] 6736: */ 6737: SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6738: SQLITE_API int sqlite3_status64( 6739: int op, 6740: sqlite3_int64 *pCurrent, 6741: sqlite3_int64 *pHighwater, 6742: int resetFlag 6743: ); 6744: 6745: 6746: /* 6747: ** CAPI3REF: Status Parameters 6748: ** KEYWORDS: {status parameters} 6749: ** 6750: ** These integer constants designate various run-time status parameters 6751: ** that can be returned by [sqlite3_status()]. 6752: ** 6753: ** <dl> 6754: ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6755: ** <dd>This parameter is the current amount of memory checked out 6756: ** using [sqlite3_malloc()], either directly or indirectly. The 6757: ** figure includes calls made to [sqlite3_malloc()] by the application 6758: ** and internal memory usage by the SQLite library. Scratch memory 6759: ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6760: ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6761: ** this parameter. The amount returned is the sum of the allocation 6762: ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6763: ** 6764: ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6765: ** <dd>This parameter records the largest memory allocation request 6766: ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6767: ** internal equivalents). Only the value returned in the 6768: ** *pHighwater parameter to [sqlite3_status()] is of interest. 6769: ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6770: ** 6771: ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6772: ** <dd>This parameter records the number of separate memory allocations 6773: ** currently checked out.</dd>)^ 6774: ** 6775: ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6776: ** <dd>This parameter returns the number of pages used out of the 6777: ** [pagecache memory allocator] that was configured using 6778: ** [SQLITE_CONFIG_PAGECACHE]. The 6779: ** value returned is in pages, not in bytes.</dd>)^ 6780: ** 6781: ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6782: ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6783: ** <dd>This parameter returns the number of bytes of page cache 6784: ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6785: ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6786: ** returned value includes allocations that overflowed because they 6787: ** where too large (they were larger than the "sz" parameter to 6788: ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6789: ** no space was left in the page cache.</dd>)^ 6790: ** 6791: ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6792: ** <dd>This parameter records the largest memory allocation request 6793: ** handed to [pagecache memory allocator]. Only the value returned in the 6794: ** *pHighwater parameter to [sqlite3_status()] is of interest. 6795: ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6796: ** 6797: ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6798: ** <dd>This parameter returns the number of allocations used out of the 6799: ** [scratch memory allocator] configured using 6800: ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6801: ** in bytes. Since a single thread may only have one scratch allocation 6802: ** outstanding at time, this parameter also reports the number of threads 6803: ** using scratch memory at the same time.</dd>)^ 6804: ** 6805: ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6806: ** <dd>This parameter returns the number of bytes of scratch memory 6807: ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6808: ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6809: ** returned include overflows because the requested allocation was too 6810: ** larger (that is, because the requested allocation was larger than the 6811: ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6812: ** slots were available. 6813: ** </dd>)^ 6814: ** 6815: ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6816: ** <dd>This parameter records the largest memory allocation request 6817: ** handed to [scratch memory allocator]. Only the value returned in the 6818: ** *pHighwater parameter to [sqlite3_status()] is of interest. 6819: ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6820: ** 6821: ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6822: ** <dd>The *pHighwater parameter records the deepest parser stack. 6823: ** The *pCurrent value is undefined. The *pHighwater value is only 6824: ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6825: ** </dl> 6826: ** 6827: ** New status parameters may be added from time to time. 6828: */ 6829: #define SQLITE_STATUS_MEMORY_USED 0 6830: #define SQLITE_STATUS_PAGECACHE_USED 1 6831: #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6832: #define SQLITE_STATUS_SCRATCH_USED 3 6833: #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6834: #define SQLITE_STATUS_MALLOC_SIZE 5 6835: #define SQLITE_STATUS_PARSER_STACK 6 6836: #define SQLITE_STATUS_PAGECACHE_SIZE 7 6837: #define SQLITE_STATUS_SCRATCH_SIZE 8 6838: #define SQLITE_STATUS_MALLOC_COUNT 9 6839: 6840: /* 6841: ** CAPI3REF: Database Connection Status 6842: ** METHOD: sqlite3 6843: ** 6844: ** ^This interface is used to retrieve runtime status information 6845: ** about a single [database connection]. ^The first argument is the 6846: ** database connection object to be interrogated. ^The second argument 6847: ** is an integer constant, taken from the set of 6848: ** [SQLITE_DBSTATUS options], that 6849: ** determines the parameter to interrogate. The set of 6850: ** [SQLITE_DBSTATUS options] is likely 6851: ** to grow in future releases of SQLite. 6852: ** 6853: ** ^The current value of the requested parameter is written into *pCur 6854: ** and the highest instantaneous value is written into *pHiwtr. ^If 6855: ** the resetFlg is true, then the highest instantaneous value is 6856: ** reset back down to the current value. 6857: ** 6858: ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6859: ** non-zero [error code] on failure. 6860: ** 6861: ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6862: */ 6863: SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6864: 6865: /* 6866: ** CAPI3REF: Status Parameters for database connections 6867: ** KEYWORDS: {SQLITE_DBSTATUS options} 6868: ** 6869: ** These constants are the available integer "verbs" that can be passed as 6870: ** the second argument to the [sqlite3_db_status()] interface. 6871: ** 6872: ** New verbs may be added in future releases of SQLite. Existing verbs 6873: ** might be discontinued. Applications should check the return code from 6874: ** [sqlite3_db_status()] to make sure that the call worked. 6875: ** The [sqlite3_db_status()] interface will return a non-zero error code 6876: ** if a discontinued or unsupported verb is invoked. 6877: ** 6878: ** <dl> 6879: ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6880: ** <dd>This parameter returns the number of lookaside memory slots currently 6881: ** checked out.</dd>)^ 6882: ** 6883: ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6884: ** <dd>This parameter returns the number malloc attempts that were 6885: ** satisfied using lookaside memory. Only the high-water value is meaningful; 6886: ** the current value is always zero.)^ 6887: ** 6888: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6889: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6890: ** <dd>This parameter returns the number malloc attempts that might have 6891: ** been satisfied using lookaside memory but failed due to the amount of 6892: ** memory requested being larger than the lookaside slot size. 6893: ** Only the high-water value is meaningful; 6894: ** the current value is always zero.)^ 6895: ** 6896: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6897: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6898: ** <dd>This parameter returns the number malloc attempts that might have 6899: ** been satisfied using lookaside memory but failed due to all lookaside 6900: ** memory already being in use. 6901: ** Only the high-water value is meaningful; 6902: ** the current value is always zero.)^ 6903: ** 6904: ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6905: ** <dd>This parameter returns the approximate number of bytes of heap 6906: ** memory used by all pager caches associated with the database connection.)^ 6907: ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6908: ** 6909: ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 6910: ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 6911: ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 6912: ** pager cache is shared between two or more connections the bytes of heap 6913: ** memory used by that pager cache is divided evenly between the attached 6914: ** connections.)^ In other words, if none of the pager caches associated 6915: ** with the database connection are shared, this request returns the same 6916: ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 6917: ** shared, the value returned by this call will be smaller than that returned 6918: ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 6919: ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 6920: ** 6921: ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6922: ** <dd>This parameter returns the approximate number of bytes of heap 6923: ** memory used to store the schema for all databases associated 6924: ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6925: ** ^The full amount of memory used by the schemas is reported, even if the 6926: ** schema memory is shared with other database connections due to 6927: ** [shared cache mode] being enabled. 6928: ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6929: ** 6930: ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6931: ** <dd>This parameter returns the approximate number of bytes of heap 6932: ** and lookaside memory used by all prepared statements associated with 6933: ** the database connection.)^ 6934: ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6935: ** </dd> 6936: ** 6937: ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6938: ** <dd>This parameter returns the number of pager cache hits that have 6939: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6940: ** is always 0. 6941: ** </dd> 6942: ** 6943: ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6944: ** <dd>This parameter returns the number of pager cache misses that have 6945: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6946: ** is always 0. 6947: ** </dd> 6948: ** 6949: ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6950: ** <dd>This parameter returns the number of dirty cache entries that have 6951: ** been written to disk. Specifically, the number of pages written to the 6952: ** wal file in wal mode databases, or the number of pages written to the 6953: ** database file in rollback mode databases. Any pages written as part of 6954: ** transaction rollback or database recovery operations are not included. 6955: ** If an IO or other error occurs while writing a page to disk, the effect 6956: ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6957: ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6958: ** </dd> 6959: ** 6960: ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6961: ** <dd>This parameter returns zero for the current value if and only if 6962: ** all foreign key constraints (deferred or immediate) have been 6963: ** resolved.)^ ^The highwater mark is always 0. 6964: ** </dd> 6965: ** </dl> 6966: */ 6967: #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6968: #define SQLITE_DBSTATUS_CACHE_USED 1 6969: #define SQLITE_DBSTATUS_SCHEMA_USED 2 6970: #define SQLITE_DBSTATUS_STMT_USED 3 6971: #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6972: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6973: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6974: #define SQLITE_DBSTATUS_CACHE_HIT 7 6975: #define SQLITE_DBSTATUS_CACHE_MISS 8 6976: #define SQLITE_DBSTATUS_CACHE_WRITE 9 6977: #define SQLITE_DBSTATUS_DEFERRED_FKS 10 6978: #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 6979: #define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 6980: 6981: 6982: /* 6983: ** CAPI3REF: Prepared Statement Status 6984: ** METHOD: sqlite3_stmt 6985: ** 6986: ** ^(Each prepared statement maintains various 6987: ** [SQLITE_STMTSTATUS counters] that measure the number 6988: ** of times it has performed specific operations.)^ These counters can 6989: ** be used to monitor the performance characteristics of the prepared 6990: ** statements. For example, if the number of table steps greatly exceeds 6991: ** the number of table searches or result rows, that would tend to indicate 6992: ** that the prepared statement is using a full table scan rather than 6993: ** an index. 6994: ** 6995: ** ^(This interface is used to retrieve and reset counter values from 6996: ** a [prepared statement]. The first argument is the prepared statement 6997: ** object to be interrogated. The second argument 6998: ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6999: ** to be interrogated.)^ 7000: ** ^The current value of the requested counter is returned. 7001: ** ^If the resetFlg is true, then the counter is reset to zero after this 7002: ** interface call returns. 7003: ** 7004: ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7005: */ 7006: SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7007: 7008: /* 7009: ** CAPI3REF: Status Parameters for prepared statements 7010: ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7011: ** 7012: ** These preprocessor macros define integer codes that name counter 7013: ** values associated with the [sqlite3_stmt_status()] interface. 7014: ** The meanings of the various counters are as follows: 7015: ** 7016: ** <dl> 7017: ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7018: ** <dd>^This is the number of times that SQLite has stepped forward in 7019: ** a table as part of a full table scan. Large numbers for this counter 7020: ** may indicate opportunities for performance improvement through 7021: ** careful use of indices.</dd> 7022: ** 7023: ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7024: ** <dd>^This is the number of sort operations that have occurred. 7025: ** A non-zero value in this counter may indicate an opportunity to 7026: ** improvement performance through careful use of indices.</dd> 7027: ** 7028: ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7029: ** <dd>^This is the number of rows inserted into transient indices that 7030: ** were created automatically in order to help joins run faster. 7031: ** A non-zero value in this counter may indicate an opportunity to 7032: ** improvement performance by adding permanent indices that do not 7033: ** need to be reinitialized each time the statement is run.</dd> 7034: ** 7035: ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7036: ** <dd>^This is the number of virtual machine operations executed 7037: ** by the prepared statement if that number is less than or equal 7038: ** to 2147483647. The number of virtual machine operations can be 7039: ** used as a proxy for the total work done by the prepared statement. 7040: ** If the number of virtual machine operations exceeds 2147483647 7041: ** then the value returned by this statement status code is undefined. 7042: ** </dd> 7043: ** </dl> 7044: */ 7045: #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7046: #define SQLITE_STMTSTATUS_SORT 2 7047: #define SQLITE_STMTSTATUS_AUTOINDEX 3 7048: #define SQLITE_STMTSTATUS_VM_STEP 4 7049: 7050: /* 7051: ** CAPI3REF: Custom Page Cache Object 7052: ** 7053: ** The sqlite3_pcache type is opaque. It is implemented by 7054: ** the pluggable module. The SQLite core has no knowledge of 7055: ** its size or internal structure and never deals with the 7056: ** sqlite3_pcache object except by holding and passing pointers 7057: ** to the object. 7058: ** 7059: ** See [sqlite3_pcache_methods2] for additional information. 7060: */ 7061: typedef struct sqlite3_pcache sqlite3_pcache; 7062: 7063: /* 7064: ** CAPI3REF: Custom Page Cache Object 7065: ** 7066: ** The sqlite3_pcache_page object represents a single page in the 7067: ** page cache. The page cache will allocate instances of this 7068: ** object. Various methods of the page cache use pointers to instances 7069: ** of this object as parameters or as their return value. 7070: ** 7071: ** See [sqlite3_pcache_methods2] for additional information. 7072: */ 7073: typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7074: struct sqlite3_pcache_page { 7075: void *pBuf; /* The content of the page */ 7076: void *pExtra; /* Extra information associated with the page */ 7077: }; 7078: 7079: /* 7080: ** CAPI3REF: Application Defined Page Cache. 7081: ** KEYWORDS: {page cache} 7082: ** 7083: ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7084: ** register an alternative page cache implementation by passing in an 7085: ** instance of the sqlite3_pcache_methods2 structure.)^ 7086: ** In many applications, most of the heap memory allocated by 7087: ** SQLite is used for the page cache. 7088: ** By implementing a 7089: ** custom page cache using this API, an application can better control 7090: ** the amount of memory consumed by SQLite, the way in which 7091: ** that memory is allocated and released, and the policies used to 7092: ** determine exactly which parts of a database file are cached and for 7093: ** how long. 7094: ** 7095: ** The alternative page cache mechanism is an 7096: ** extreme measure that is only needed by the most demanding applications. 7097: ** The built-in page cache is recommended for most uses. 7098: ** 7099: ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7100: ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7101: ** the application may discard the parameter after the call to 7102: ** [sqlite3_config()] returns.)^ 7103: ** 7104: ** [[the xInit() page cache method]] 7105: ** ^(The xInit() method is called once for each effective 7106: ** call to [sqlite3_initialize()])^ 7107: ** (usually only once during the lifetime of the process). ^(The xInit() 7108: ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7109: ** The intent of the xInit() method is to set up global data structures 7110: ** required by the custom page cache implementation. 7111: ** ^(If the xInit() method is NULL, then the 7112: ** built-in default page cache is used instead of the application defined 7113: ** page cache.)^ 7114: ** 7115: ** [[the xShutdown() page cache method]] 7116: ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7117: ** It can be used to clean up 7118: ** any outstanding resources before process shutdown, if required. 7119: ** ^The xShutdown() method may be NULL. 7120: ** 7121: ** ^SQLite automatically serializes calls to the xInit method, 7122: ** so the xInit method need not be threadsafe. ^The 7123: ** xShutdown method is only called from [sqlite3_shutdown()] so it does 7124: ** not need to be threadsafe either. All other methods must be threadsafe 7125: ** in multithreaded applications. 7126: ** 7127: ** ^SQLite will never invoke xInit() more than once without an intervening 7128: ** call to xShutdown(). 7129: ** 7130: ** [[the xCreate() page cache methods]] 7131: ** ^SQLite invokes the xCreate() method to construct a new cache instance. 7132: ** SQLite will typically create one cache instance for each open database file, 7133: ** though this is not guaranteed. ^The 7134: ** first parameter, szPage, is the size in bytes of the pages that must 7135: ** be allocated by the cache. ^szPage will always a power of two. ^The 7136: ** second parameter szExtra is a number of bytes of extra storage 7137: ** associated with each page cache entry. ^The szExtra parameter will 7138: ** a number less than 250. SQLite will use the 7139: ** extra szExtra bytes on each page to store metadata about the underlying 7140: ** database page on disk. The value passed into szExtra depends 7141: ** on the SQLite version, the target platform, and how SQLite was compiled. 7142: ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7143: ** created will be used to cache database pages of a file stored on disk, or 7144: ** false if it is used for an in-memory database. The cache implementation 7145: ** does not have to do anything special based with the value of bPurgeable; 7146: ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7147: ** never invoke xUnpin() except to deliberately delete a page. 7148: ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7149: ** false will always have the "discard" flag set to true. 7150: ** ^Hence, a cache created with bPurgeable false will 7151: ** never contain any unpinned pages. 7152: ** 7153: ** [[the xCachesize() page cache method]] 7154: ** ^(The xCachesize() method may be called at any time by SQLite to set the 7155: ** suggested maximum cache-size (number of pages stored by) the cache 7156: ** instance passed as the first argument. This is the value configured using 7157: ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7158: ** parameter, the implementation is not required to do anything with this 7159: ** value; it is advisory only. 7160: ** 7161: ** [[the xPagecount() page cache methods]] 7162: ** The xPagecount() method must return the number of pages currently 7163: ** stored in the cache, both pinned and unpinned. 7164: ** 7165: ** [[the xFetch() page cache methods]] 7166: ** The xFetch() method locates a page in the cache and returns a pointer to 7167: ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7168: ** The pBuf element of the returned sqlite3_pcache_page object will be a 7169: ** pointer to a buffer of szPage bytes used to store the content of a 7170: ** single database page. The pExtra element of sqlite3_pcache_page will be 7171: ** a pointer to the szExtra bytes of extra storage that SQLite has requested 7172: ** for each entry in the page cache. 7173: ** 7174: ** The page to be fetched is determined by the key. ^The minimum key value 7175: ** is 1. After it has been retrieved using xFetch, the page is considered 7176: ** to be "pinned". 7177: ** 7178: ** If the requested page is already in the page cache, then the page cache 7179: ** implementation must return a pointer to the page buffer with its content 7180: ** intact. If the requested page is not already in the cache, then the 7181: ** cache implementation should use the value of the createFlag 7182: ** parameter to help it determined what action to take: 7183: ** 7184: ** <table border=1 width=85% align=center> 7185: ** <tr><th> createFlag <th> Behavior when page is not already in cache 7186: ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7187: ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7188: ** Otherwise return NULL. 7189: ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7190: ** NULL if allocating a new page is effectively impossible. 7191: ** </table> 7192: ** 7193: ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7194: ** will only use a createFlag of 2 after a prior call with a createFlag of 1 7195: ** failed.)^ In between the to xFetch() calls, SQLite may 7196: ** attempt to unpin one or more cache pages by spilling the content of 7197: ** pinned pages to disk and synching the operating system disk cache. 7198: ** 7199: ** [[the xUnpin() page cache method]] 7200: ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7201: ** as its second argument. If the third parameter, discard, is non-zero, 7202: ** then the page must be evicted from the cache. 7203: ** ^If the discard parameter is 7204: ** zero, then the page may be discarded or retained at the discretion of 7205: ** page cache implementation. ^The page cache implementation 7206: ** may choose to evict unpinned pages at any time. 7207: ** 7208: ** The cache must not perform any reference counting. A single 7209: ** call to xUnpin() unpins the page regardless of the number of prior calls 7210: ** to xFetch(). 7211: ** 7212: ** [[the xRekey() page cache methods]] 7213: ** The xRekey() method is used to change the key value associated with the 7214: ** page passed as the second argument. If the cache 7215: ** previously contains an entry associated with newKey, it must be 7216: ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7217: ** to be pinned. 7218: ** 7219: ** When SQLite calls the xTruncate() method, the cache must discard all 7220: ** existing cache entries with page numbers (keys) greater than or equal 7221: ** to the value of the iLimit parameter passed to xTruncate(). If any 7222: ** of these pages are pinned, they are implicitly unpinned, meaning that 7223: ** they can be safely discarded. 7224: ** 7225: ** [[the xDestroy() page cache method]] 7226: ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7227: ** All resources associated with the specified cache should be freed. ^After 7228: ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7229: ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7230: ** functions. 7231: ** 7232: ** [[the xShrink() page cache method]] 7233: ** ^SQLite invokes the xShrink() method when it wants the page cache to 7234: ** free up as much of heap memory as possible. The page cache implementation 7235: ** is not obligated to free any memory, but well-behaved implementations should 7236: ** do their best. 7237: */ 7238: typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7239: struct sqlite3_pcache_methods2 { 7240: int iVersion; 7241: void *pArg; 7242: int (*xInit)(void*); 7243: void (*xShutdown)(void*); 7244: sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7245: void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7246: int (*xPagecount)(sqlite3_pcache*); 7247: sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7248: void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7249: void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7250: unsigned oldKey, unsigned newKey); 7251: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7252: void (*xDestroy)(sqlite3_pcache*); 7253: void (*xShrink)(sqlite3_pcache*); 7254: }; 7255: 7256: /* 7257: ** This is the obsolete pcache_methods object that has now been replaced 7258: ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7259: ** retained in the header file for backwards compatibility only. 7260: */ 7261: typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7262: struct sqlite3_pcache_methods { 7263: void *pArg; 7264: int (*xInit)(void*); 7265: void (*xShutdown)(void*); 7266: sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7267: void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7268: int (*xPagecount)(sqlite3_pcache*); 7269: void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7270: void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7271: void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7272: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7273: void (*xDestroy)(sqlite3_pcache*); 7274: }; 7275: 7276: 7277: /* 7278: ** CAPI3REF: Online Backup Object 7279: ** 7280: ** The sqlite3_backup object records state information about an ongoing 7281: ** online backup operation. ^The sqlite3_backup object is created by 7282: ** a call to [sqlite3_backup_init()] and is destroyed by a call to 7283: ** [sqlite3_backup_finish()]. 7284: ** 7285: ** See Also: [Using the SQLite Online Backup API] 7286: */ 7287: typedef struct sqlite3_backup sqlite3_backup; 7288: 7289: /* 7290: ** CAPI3REF: Online Backup API. 7291: ** 7292: ** The backup API copies the content of one database into another. 7293: ** It is useful either for creating backups of databases or 7294: ** for copying in-memory databases to or from persistent files. 7295: ** 7296: ** See Also: [Using the SQLite Online Backup API] 7297: ** 7298: ** ^SQLite holds a write transaction open on the destination database file 7299: ** for the duration of the backup operation. 7300: ** ^The source database is read-locked only while it is being read; 7301: ** it is not locked continuously for the entire backup operation. 7302: ** ^Thus, the backup may be performed on a live source database without 7303: ** preventing other database connections from 7304: ** reading or writing to the source database while the backup is underway. 7305: ** 7306: ** ^(To perform a backup operation: 7307: ** <ol> 7308: ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7309: ** backup, 7310: ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7311: ** the data between the two databases, and finally 7312: ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7313: ** associated with the backup operation. 7314: ** </ol>)^ 7315: ** There should be exactly one call to sqlite3_backup_finish() for each 7316: ** successful call to sqlite3_backup_init(). 7317: ** 7318: ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7319: ** 7320: ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7321: ** [database connection] associated with the destination database 7322: ** and the database name, respectively. 7323: ** ^The database name is "main" for the main database, "temp" for the 7324: ** temporary database, or the name specified after the AS keyword in 7325: ** an [ATTACH] statement for an attached database. 7326: ** ^The S and M arguments passed to 7327: ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7328: ** and database name of the source database, respectively. 7329: ** ^The source and destination [database connections] (parameters S and D) 7330: ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7331: ** an error. 7332: ** 7333: ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7334: ** there is already a read or read-write transaction open on the 7335: ** destination database. 7336: ** 7337: ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7338: ** returned and an error code and error message are stored in the 7339: ** destination [database connection] D. 7340: ** ^The error code and message for the failed call to sqlite3_backup_init() 7341: ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7342: ** [sqlite3_errmsg16()] functions. 7343: ** ^A successful call to sqlite3_backup_init() returns a pointer to an 7344: ** [sqlite3_backup] object. 7345: ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7346: ** sqlite3_backup_finish() functions to perform the specified backup 7347: ** operation. 7348: ** 7349: ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7350: ** 7351: ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7352: ** the source and destination databases specified by [sqlite3_backup] object B. 7353: ** ^If N is negative, all remaining source pages are copied. 7354: ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7355: ** are still more pages to be copied, then the function returns [SQLITE_OK]. 7356: ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7357: ** from source to destination, then it returns [SQLITE_DONE]. 7358: ** ^If an error occurs while running sqlite3_backup_step(B,N), 7359: ** then an [error code] is returned. ^As well as [SQLITE_OK] and 7360: ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7361: ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7362: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7363: ** 7364: ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7365: ** <ol> 7366: ** <li> the destination database was opened read-only, or 7367: ** <li> the destination database is using write-ahead-log journaling 7368: ** and the destination and source page sizes differ, or 7369: ** <li> the destination database is an in-memory database and the 7370: ** destination and source page sizes differ. 7371: ** </ol>)^ 7372: ** 7373: ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7374: ** the [sqlite3_busy_handler | busy-handler function] 7375: ** is invoked (if one is specified). ^If the 7376: ** busy-handler returns non-zero before the lock is available, then 7377: ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7378: ** sqlite3_backup_step() can be retried later. ^If the source 7379: ** [database connection] 7380: ** is being used to write to the source database when sqlite3_backup_step() 7381: ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7382: ** case the call to sqlite3_backup_step() can be retried later on. ^(If 7383: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7384: ** [SQLITE_READONLY] is returned, then 7385: ** there is no point in retrying the call to sqlite3_backup_step(). These 7386: ** errors are considered fatal.)^ The application must accept 7387: ** that the backup operation has failed and pass the backup operation handle 7388: ** to the sqlite3_backup_finish() to release associated resources. 7389: ** 7390: ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7391: ** on the destination file. ^The exclusive lock is not released until either 7392: ** sqlite3_backup_finish() is called or the backup operation is complete 7393: ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7394: ** sqlite3_backup_step() obtains a [shared lock] on the source database that 7395: ** lasts for the duration of the sqlite3_backup_step() call. 7396: ** ^Because the source database is not locked between calls to 7397: ** sqlite3_backup_step(), the source database may be modified mid-way 7398: ** through the backup process. ^If the source database is modified by an 7399: ** external process or via a database connection other than the one being 7400: ** used by the backup operation, then the backup will be automatically 7401: ** restarted by the next call to sqlite3_backup_step(). ^If the source 7402: ** database is modified by the using the same database connection as is used 7403: ** by the backup operation, then the backup database is automatically 7404: ** updated at the same time. 7405: ** 7406: ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7407: ** 7408: ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7409: ** application wishes to abandon the backup operation, the application 7410: ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7411: ** ^The sqlite3_backup_finish() interfaces releases all 7412: ** resources associated with the [sqlite3_backup] object. 7413: ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7414: ** active write-transaction on the destination database is rolled back. 7415: ** The [sqlite3_backup] object is invalid 7416: ** and may not be used following a call to sqlite3_backup_finish(). 7417: ** 7418: ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7419: ** sqlite3_backup_step() errors occurred, regardless or whether or not 7420: ** sqlite3_backup_step() completed. 7421: ** ^If an out-of-memory condition or IO error occurred during any prior 7422: ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7423: ** sqlite3_backup_finish() returns the corresponding [error code]. 7424: ** 7425: ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7426: ** is not a permanent error and does not affect the return value of 7427: ** sqlite3_backup_finish(). 7428: ** 7429: ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7430: ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7431: ** 7432: ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7433: ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7434: ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7435: ** in the source database at the conclusion of the most recent 7436: ** sqlite3_backup_step(). 7437: ** ^(The values returned by these functions are only updated by 7438: ** sqlite3_backup_step(). If the source database is modified in a way that 7439: ** changes the size of the source database or the number of pages remaining, 7440: ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7441: ** and sqlite3_backup_remaining() until after the next 7442: ** sqlite3_backup_step().)^ 7443: ** 7444: ** <b>Concurrent Usage of Database Handles</b> 7445: ** 7446: ** ^The source [database connection] may be used by the application for other 7447: ** purposes while a backup operation is underway or being initialized. 7448: ** ^If SQLite is compiled and configured to support threadsafe database 7449: ** connections, then the source database connection may be used concurrently 7450: ** from within other threads. 7451: ** 7452: ** However, the application must guarantee that the destination 7453: ** [database connection] is not passed to any other API (by any thread) after 7454: ** sqlite3_backup_init() is called and before the corresponding call to 7455: ** sqlite3_backup_finish(). SQLite does not currently check to see 7456: ** if the application incorrectly accesses the destination [database connection] 7457: ** and so no error code is reported, but the operations may malfunction 7458: ** nevertheless. Use of the destination database connection while a 7459: ** backup is in progress might also also cause a mutex deadlock. 7460: ** 7461: ** If running in [shared cache mode], the application must 7462: ** guarantee that the shared cache used by the destination database 7463: ** is not accessed while the backup is running. In practice this means 7464: ** that the application must guarantee that the disk file being 7465: ** backed up to is not accessed by any connection within the process, 7466: ** not just the specific connection that was passed to sqlite3_backup_init(). 7467: ** 7468: ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7469: ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7470: ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7471: ** APIs are not strictly speaking threadsafe. If they are invoked at the 7472: ** same time as another thread is invoking sqlite3_backup_step() it is 7473: ** possible that they return invalid values. 7474: */ 7475: SQLITE_API sqlite3_backup *sqlite3_backup_init( 7476: sqlite3 *pDest, /* Destination database handle */ 7477: const char *zDestName, /* Destination database name */ 7478: sqlite3 *pSource, /* Source database handle */ 7479: const char *zSourceName /* Source database name */ 7480: ); 7481: SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7482: SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 7483: SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 7484: SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 7485: 7486: /* 7487: ** CAPI3REF: Unlock Notification 7488: ** METHOD: sqlite3 7489: ** 7490: ** ^When running in shared-cache mode, a database operation may fail with 7491: ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7492: ** individual tables within the shared-cache cannot be obtained. See 7493: ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7494: ** ^This API may be used to register a callback that SQLite will invoke 7495: ** when the connection currently holding the required lock relinquishes it. 7496: ** ^This API is only available if the library was compiled with the 7497: ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7498: ** 7499: ** See Also: [Using the SQLite Unlock Notification Feature]. 7500: ** 7501: ** ^Shared-cache locks are released when a database connection concludes 7502: ** its current transaction, either by committing it or rolling it back. 7503: ** 7504: ** ^When a connection (known as the blocked connection) fails to obtain a 7505: ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7506: ** identity of the database connection (the blocking connection) that 7507: ** has locked the required resource is stored internally. ^After an 7508: ** application receives an SQLITE_LOCKED error, it may call the 7509: ** sqlite3_unlock_notify() method with the blocked connection handle as 7510: ** the first argument to register for a callback that will be invoked 7511: ** when the blocking connections current transaction is concluded. ^The 7512: ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7513: ** call that concludes the blocking connections transaction. 7514: ** 7515: ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7516: ** there is a chance that the blocking connection will have already 7517: ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7518: ** If this happens, then the specified callback is invoked immediately, 7519: ** from within the call to sqlite3_unlock_notify().)^ 7520: ** 7521: ** ^If the blocked connection is attempting to obtain a write-lock on a 7522: ** shared-cache table, and more than one other connection currently holds 7523: ** a read-lock on the same table, then SQLite arbitrarily selects one of 7524: ** the other connections to use as the blocking connection. 7525: ** 7526: ** ^(There may be at most one unlock-notify callback registered by a 7527: ** blocked connection. If sqlite3_unlock_notify() is called when the 7528: ** blocked connection already has a registered unlock-notify callback, 7529: ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7530: ** called with a NULL pointer as its second argument, then any existing 7531: ** unlock-notify callback is canceled. ^The blocked connections 7532: ** unlock-notify callback may also be canceled by closing the blocked 7533: ** connection using [sqlite3_close()]. 7534: ** 7535: ** The unlock-notify callback is not reentrant. If an application invokes 7536: ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7537: ** crash or deadlock may be the result. 7538: ** 7539: ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7540: ** returns SQLITE_OK. 7541: ** 7542: ** <b>Callback Invocation Details</b> 7543: ** 7544: ** When an unlock-notify callback is registered, the application provides a 7545: ** single void* pointer that is passed to the callback when it is invoked. 7546: ** However, the signature of the callback function allows SQLite to pass 7547: ** it an array of void* context pointers. The first argument passed to 7548: ** an unlock-notify callback is a pointer to an array of void* pointers, 7549: ** and the second is the number of entries in the array. 7550: ** 7551: ** When a blocking connections transaction is concluded, there may be 7552: ** more than one blocked connection that has registered for an unlock-notify 7553: ** callback. ^If two or more such blocked connections have specified the 7554: ** same callback function, then instead of invoking the callback function 7555: ** multiple times, it is invoked once with the set of void* context pointers 7556: ** specified by the blocked connections bundled together into an array. 7557: ** This gives the application an opportunity to prioritize any actions 7558: ** related to the set of unblocked database connections. 7559: ** 7560: ** <b>Deadlock Detection</b> 7561: ** 7562: ** Assuming that after registering for an unlock-notify callback a 7563: ** database waits for the callback to be issued before taking any further 7564: ** action (a reasonable assumption), then using this API may cause the 7565: ** application to deadlock. For example, if connection X is waiting for 7566: ** connection Y's transaction to be concluded, and similarly connection 7567: ** Y is waiting on connection X's transaction, then neither connection 7568: ** will proceed and the system may remain deadlocked indefinitely. 7569: ** 7570: ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7571: ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7572: ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7573: ** unlock-notify callback is registered. The system is said to be in 7574: ** a deadlocked state if connection A has registered for an unlock-notify 7575: ** callback on the conclusion of connection B's transaction, and connection 7576: ** B has itself registered for an unlock-notify callback when connection 7577: ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7578: ** the system is also considered to be deadlocked if connection B has 7579: ** registered for an unlock-notify callback on the conclusion of connection 7580: ** C's transaction, where connection C is waiting on connection A. ^Any 7581: ** number of levels of indirection are allowed. 7582: ** 7583: ** <b>The "DROP TABLE" Exception</b> 7584: ** 7585: ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7586: ** always appropriate to call sqlite3_unlock_notify(). There is however, 7587: ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7588: ** SQLite checks if there are any currently executing SELECT statements 7589: ** that belong to the same connection. If there are, SQLITE_LOCKED is 7590: ** returned. In this case there is no "blocking connection", so invoking 7591: ** sqlite3_unlock_notify() results in the unlock-notify callback being 7592: ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7593: ** or "DROP INDEX" query, an infinite loop might be the result. 7594: ** 7595: ** One way around this problem is to check the extended error code returned 7596: ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7597: ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7598: ** the special "DROP TABLE/INDEX" case, the extended error code is just 7599: ** SQLITE_LOCKED.)^ 7600: */ 7601: SQLITE_API int sqlite3_unlock_notify( 7602: sqlite3 *pBlocked, /* Waiting connection */ 7603: void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7604: void *pNotifyArg /* Argument to pass to xNotify */ 7605: ); 7606: 7607: 7608: /* 7609: ** CAPI3REF: String Comparison 7610: ** 7611: ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7612: ** and extensions to compare the contents of two buffers containing UTF-8 7613: ** strings in a case-independent fashion, using the same definition of "case 7614: ** independence" that SQLite uses internally when comparing identifiers. 7615: */ 7616: SQLITE_API int sqlite3_stricmp(const char *, const char *); 7617: SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 7618: 7619: /* 7620: ** CAPI3REF: String Globbing 7621: * 7622: ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7623: ** string X matches the [GLOB] pattern P. 7624: ** ^The definition of [GLOB] pattern matching used in 7625: ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7626: ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7627: ** is case sensitive. 7628: ** 7629: ** Note that this routine returns zero on a match and non-zero if the strings 7630: ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7631: ** 7632: ** See also: [sqlite3_strlike()]. 7633: */ 7634: SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 7635: 7636: /* 7637: ** CAPI3REF: String LIKE Matching 7638: * 7639: ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7640: ** string X matches the [LIKE] pattern P with escape character E. 7641: ** ^The definition of [LIKE] pattern matching used in 7642: ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7643: ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7644: ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7645: ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7646: ** insensitive - equivalent upper and lower case ASCII characters match 7647: ** one another. 7648: ** 7649: ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7650: ** only ASCII characters are case folded. 7651: ** 7652: ** Note that this routine returns zero on a match and non-zero if the strings 7653: ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7654: ** 7655: ** See also: [sqlite3_strglob()]. 7656: */ 7657: SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7658: 7659: /* 7660: ** CAPI3REF: Error Logging Interface 7661: ** 7662: ** ^The [sqlite3_log()] interface writes a message into the [error log] 7663: ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7664: ** ^If logging is enabled, the zFormat string and subsequent arguments are 7665: ** used with [sqlite3_snprintf()] to generate the final output string. 7666: ** 7667: ** The sqlite3_log() interface is intended for use by extensions such as 7668: ** virtual tables, collating functions, and SQL functions. While there is 7669: ** nothing to prevent an application from calling sqlite3_log(), doing so 7670: ** is considered bad form. 7671: ** 7672: ** The zFormat string must not be NULL. 7673: ** 7674: ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7675: ** will not use dynamically allocated memory. The log message is stored in 7676: ** a fixed-length buffer on the stack. If the log message is longer than 7677: ** a few hundred characters, it will be truncated to the length of the 7678: ** buffer. 7679: */ 7680: SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 7681: 7682: /* 7683: ** CAPI3REF: Write-Ahead Log Commit Hook 7684: ** METHOD: sqlite3 7685: ** 7686: ** ^The [sqlite3_wal_hook()] function is used to register a callback that 7687: ** is invoked each time data is committed to a database in wal mode. 7688: ** 7689: ** ^(The callback is invoked by SQLite after the commit has taken place and 7690: ** the associated write-lock on the database released)^, so the implementation 7691: ** may read, write or [checkpoint] the database as required. 7692: ** 7693: ** ^The first parameter passed to the callback function when it is invoked 7694: ** is a copy of the third parameter passed to sqlite3_wal_hook() when 7695: ** registering the callback. ^The second is a copy of the database handle. 7696: ** ^The third parameter is the name of the database that was written to - 7697: ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7698: ** is the number of pages currently in the write-ahead log file, 7699: ** including those that were just committed. 7700: ** 7701: ** The callback function should normally return [SQLITE_OK]. ^If an error 7702: ** code is returned, that error will propagate back up through the 7703: ** SQLite code base to cause the statement that provoked the callback 7704: ** to report an error, though the commit will have still occurred. If the 7705: ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7706: ** that does not correspond to any valid SQLite error code, the results 7707: ** are undefined. 7708: ** 7709: ** A single database handle may have at most a single write-ahead log callback 7710: ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7711: ** previously registered write-ahead log callback. ^Note that the 7712: ** [sqlite3_wal_autocheckpoint()] interface and the 7713: ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7714: ** overwrite any prior [sqlite3_wal_hook()] settings. 7715: */ 7716: SQLITE_API void *sqlite3_wal_hook( 7717: sqlite3*, 7718: int(*)(void *,sqlite3*,const char*,int), 7719: void* 7720: ); 7721: 7722: /* 7723: ** CAPI3REF: Configure an auto-checkpoint 7724: ** METHOD: sqlite3 7725: ** 7726: ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7727: ** [sqlite3_wal_hook()] that causes any database on [database connection] D 7728: ** to automatically [checkpoint] 7729: ** after committing a transaction if there are N or 7730: ** more frames in the [write-ahead log] file. ^Passing zero or 7731: ** a negative value as the nFrame parameter disables automatic 7732: ** checkpoints entirely. 7733: ** 7734: ** ^The callback registered by this function replaces any existing callback 7735: ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7736: ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7737: ** configured by this function. 7738: ** 7739: ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7740: ** from SQL. 7741: ** 7742: ** ^Checkpoints initiated by this mechanism are 7743: ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7744: ** 7745: ** ^Every new [database connection] defaults to having the auto-checkpoint 7746: ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7747: ** pages. The use of this interface 7748: ** is only necessary if the default setting is found to be suboptimal 7749: ** for a particular application. 7750: */ 7751: SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7752: 7753: /* 7754: ** CAPI3REF: Checkpoint a database 7755: ** METHOD: sqlite3 7756: ** 7757: ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7758: ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7759: ** 7760: ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7761: ** [write-ahead log] for database X on [database connection] D to be 7762: ** transferred into the database file and for the write-ahead log to 7763: ** be reset. See the [checkpointing] documentation for addition 7764: ** information. 7765: ** 7766: ** This interface used to be the only way to cause a checkpoint to 7767: ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7768: ** interface was added. This interface is retained for backwards 7769: ** compatibility and as a convenience for applications that need to manually 7770: ** start a callback but which do not need the full power (and corresponding 7771: ** complication) of [sqlite3_wal_checkpoint_v2()]. 7772: */ 7773: SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7774: 7775: /* 7776: ** CAPI3REF: Checkpoint a database 7777: ** METHOD: sqlite3 7778: ** 7779: ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7780: ** operation on database X of [database connection] D in mode M. Status 7781: ** information is written back into integers pointed to by L and C.)^ 7782: ** ^(The M parameter must be a valid [checkpoint mode]:)^ 7783: ** 7784: ** <dl> 7785: ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7786: ** ^Checkpoint as many frames as possible without waiting for any database 7787: ** readers or writers to finish, then sync the database file if all frames 7788: ** in the log were checkpointed. ^The [busy-handler callback] 7789: ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7790: ** ^On the other hand, passive mode might leave the checkpoint unfinished 7791: ** if there are concurrent readers or writers. 7792: ** 7793: ** <dt>SQLITE_CHECKPOINT_FULL<dd> 7794: ** ^This mode blocks (it invokes the 7795: ** [sqlite3_busy_handler|busy-handler callback]) until there is no 7796: ** database writer and all readers are reading from the most recent database 7797: ** snapshot. ^It then checkpoints all frames in the log file and syncs the 7798: ** database file. ^This mode blocks new database writers while it is pending, 7799: ** but new database readers are allowed to continue unimpeded. 7800: ** 7801: ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7802: ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7803: ** that after checkpointing the log file it blocks (calls the 7804: ** [busy-handler callback]) 7805: ** until all readers are reading from the database file only. ^This ensures 7806: ** that the next writer will restart the log file from the beginning. 7807: ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7808: ** database writer attempts while it is pending, but does not impede readers. 7809: ** 7810: ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7811: ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7812: ** addition that it also truncates the log file to zero bytes just prior 7813: ** to a successful return. 7814: ** </dl> 7815: ** 7816: ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7817: ** the log file or to -1 if the checkpoint could not run because 7818: ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7819: ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7820: ** log file (including any that were already checkpointed before the function 7821: ** was called) or to -1 if the checkpoint could not run due to an error or 7822: ** because the database is not in WAL mode. ^Note that upon successful 7823: ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7824: ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7825: ** 7826: ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7827: ** any other process is running a checkpoint operation at the same time, the 7828: ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7829: ** busy-handler configured, it will not be invoked in this case. 7830: ** 7831: ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7832: ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7833: ** obtained immediately, and a busy-handler is configured, it is invoked and 7834: ** the writer lock retried until either the busy-handler returns 0 or the lock 7835: ** is successfully obtained. ^The busy-handler is also invoked while waiting for 7836: ** database readers as described above. ^If the busy-handler returns 0 before 7837: ** the writer lock is obtained or while waiting for database readers, the 7838: ** checkpoint operation proceeds from that point in the same way as 7839: ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7840: ** without blocking any further. ^SQLITE_BUSY is returned in this case. 7841: ** 7842: ** ^If parameter zDb is NULL or points to a zero length string, then the 7843: ** specified operation is attempted on all WAL databases [attached] to 7844: ** [database connection] db. In this case the 7845: ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7846: ** an SQLITE_BUSY error is encountered when processing one or more of the 7847: ** attached WAL databases, the operation is still attempted on any remaining 7848: ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7849: ** error occurs while processing an attached database, processing is abandoned 7850: ** and the error code is returned to the caller immediately. ^If no error 7851: ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7852: ** databases, SQLITE_OK is returned. 7853: ** 7854: ** ^If database zDb is the name of an attached database that is not in WAL 7855: ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7856: ** zDb is not NULL (or a zero length string) and is not the name of any 7857: ** attached database, SQLITE_ERROR is returned to the caller. 7858: ** 7859: ** ^Unless it returns SQLITE_MISUSE, 7860: ** the sqlite3_wal_checkpoint_v2() interface 7861: ** sets the error information that is queried by 7862: ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7863: ** 7864: ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7865: ** from SQL. 7866: */ 7867: SQLITE_API int sqlite3_wal_checkpoint_v2( 7868: sqlite3 *db, /* Database handle */ 7869: const char *zDb, /* Name of attached database (or NULL) */ 7870: int eMode, /* SQLITE_CHECKPOINT_* value */ 7871: int *pnLog, /* OUT: Size of WAL log in frames */ 7872: int *pnCkpt /* OUT: Total number of frames checkpointed */ 7873: ); 7874: 7875: /* 7876: ** CAPI3REF: Checkpoint Mode Values 7877: ** KEYWORDS: {checkpoint mode} 7878: ** 7879: ** These constants define all valid values for the "checkpoint mode" passed 7880: ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7881: ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7882: ** meaning of each of these checkpoint modes. 7883: */ 7884: #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7885: #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7886: #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7887: #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7888: 7889: /* 7890: ** CAPI3REF: Virtual Table Interface Configuration 7891: ** 7892: ** This function may be called by either the [xConnect] or [xCreate] method 7893: ** of a [virtual table] implementation to configure 7894: ** various facets of the virtual table interface. 7895: ** 7896: ** If this interface is invoked outside the context of an xConnect or 7897: ** xCreate virtual table method then the behavior is undefined. 7898: ** 7899: ** At present, there is only one option that may be configured using 7900: ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7901: ** may be added in the future. 7902: */ 7903: SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 7904: 7905: /* 7906: ** CAPI3REF: Virtual Table Configuration Options 7907: ** 7908: ** These macros define the various options to the 7909: ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7910: ** can use to customize and optimize their behavior. 7911: ** 7912: ** <dl> 7913: ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7914: ** <dd>Calls of the form 7915: ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7916: ** where X is an integer. If X is zero, then the [virtual table] whose 7917: ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7918: ** support constraints. In this configuration (which is the default) if 7919: ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7920: ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7921: ** specified as part of the users SQL statement, regardless of the actual 7922: ** ON CONFLICT mode specified. 7923: ** 7924: ** If X is non-zero, then the virtual table implementation guarantees 7925: ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7926: ** any modifications to internal or persistent data structures have been made. 7927: ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7928: ** is able to roll back a statement or database transaction, and abandon 7929: ** or continue processing the current SQL statement as appropriate. 7930: ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7931: ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7932: ** had been ABORT. 7933: ** 7934: ** Virtual table implementations that are required to handle OR REPLACE 7935: ** must do so within the [xUpdate] method. If a call to the 7936: ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7937: ** CONFLICT policy is REPLACE, the virtual table implementation should 7938: ** silently replace the appropriate rows within the xUpdate callback and 7939: ** return SQLITE_OK. Or, if this is not possible, it may return 7940: ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7941: ** constraint handling. 7942: ** </dl> 7943: */ 7944: #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7945: 7946: /* 7947: ** CAPI3REF: Determine The Virtual Table Conflict Policy 7948: ** 7949: ** This function may only be called from within a call to the [xUpdate] method 7950: ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7951: ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7952: ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7953: ** of the SQL statement that triggered the call to the [xUpdate] method of the 7954: ** [virtual table]. 7955: */ 7956: SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 7957: 7958: /* 7959: ** CAPI3REF: Conflict resolution modes 7960: ** KEYWORDS: {conflict resolution mode} 7961: ** 7962: ** These constants are returned by [sqlite3_vtab_on_conflict()] to 7963: ** inform a [virtual table] implementation what the [ON CONFLICT] mode 7964: ** is for the SQL statement being evaluated. 7965: ** 7966: ** Note that the [SQLITE_IGNORE] constant is also used as a potential 7967: ** return value from the [sqlite3_set_authorizer()] callback and that 7968: ** [SQLITE_ABORT] is also a [result code]. 7969: */ 7970: #define SQLITE_ROLLBACK 1 7971: /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7972: #define SQLITE_FAIL 3 7973: /* #define SQLITE_ABORT 4 // Also an error code */ 7974: #define SQLITE_REPLACE 5 7975: 7976: /* 7977: ** CAPI3REF: Prepared Statement Scan Status Opcodes 7978: ** KEYWORDS: {scanstatus options} 7979: ** 7980: ** The following constants can be used for the T parameter to the 7981: ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7982: ** different metric for sqlite3_stmt_scanstatus() to return. 7983: ** 7984: ** When the value returned to V is a string, space to hold that string is 7985: ** managed by the prepared statement S and will be automatically freed when 7986: ** S is finalized. 7987: ** 7988: ** <dl> 7989: ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7990: ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7991: ** set to the total number of times that the X-th loop has run.</dd> 7992: ** 7993: ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7994: ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7995: ** to the total number of rows examined by all iterations of the X-th loop.</dd> 7996: ** 7997: ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7998: ** <dd>^The "double" variable pointed to by the T parameter will be set to the 7999: ** query planner's estimate for the average number of rows output from each 8000: ** iteration of the X-th loop. If the query planner's estimates was accurate, 8001: ** then this value will approximate the quotient NVISIT/NLOOP and the 8002: ** product of this value for all prior loops with the same SELECTID will 8003: ** be the NLOOP value for the current loop. 8004: ** 8005: ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8006: ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8007: ** to a zero-terminated UTF-8 string containing the name of the index or table 8008: ** used for the X-th loop. 8009: ** 8010: ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8011: ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8012: ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8013: ** description for the X-th loop. 8014: ** 8015: ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8016: ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8017: ** "select-id" for the X-th loop. The select-id identifies which query or 8018: ** subquery the loop is part of. The main query has a select-id of zero. 8019: ** The select-id is the same value as is output in the first column 8020: ** of an [EXPLAIN QUERY PLAN] query. 8021: ** </dl> 8022: */ 8023: #define SQLITE_SCANSTAT_NLOOP 0 8024: #define SQLITE_SCANSTAT_NVISIT 1 8025: #define SQLITE_SCANSTAT_EST 2 8026: #define SQLITE_SCANSTAT_NAME 3 8027: #define SQLITE_SCANSTAT_EXPLAIN 4 8028: #define SQLITE_SCANSTAT_SELECTID 5 8029: 8030: /* 8031: ** CAPI3REF: Prepared Statement Scan Status 8032: ** METHOD: sqlite3_stmt 8033: ** 8034: ** This interface returns information about the predicted and measured 8035: ** performance for pStmt. Advanced applications can use this 8036: ** interface to compare the predicted and the measured performance and 8037: ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8038: ** 8039: ** Since this interface is expected to be rarely used, it is only 8040: ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8041: ** compile-time option. 8042: ** 8043: ** The "iScanStatusOp" parameter determines which status information to return. 8044: ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8045: ** of this interface is undefined. 8046: ** ^The requested measurement is written into a variable pointed to by 8047: ** the "pOut" parameter. 8048: ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8049: ** Loops are numbered starting from zero. ^If idx is out of range - less than 8050: ** zero or greater than or equal to the total number of loops used to implement 8051: ** the statement - a non-zero value is returned and the variable that pOut 8052: ** points to is unchanged. 8053: ** 8054: ** ^Statistics might not be available for all loops in all statements. ^In cases 8055: ** where there exist loops with no available statistics, this function behaves 8056: ** as if the loop did not exist - it returns non-zero and leave the variable 8057: ** that pOut points to unchanged. 8058: ** 8059: ** See also: [sqlite3_stmt_scanstatus_reset()] 8060: */ 8061: SQLITE_API int sqlite3_stmt_scanstatus( 8062: sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8063: int idx, /* Index of loop to report on */ 8064: int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8065: void *pOut /* Result written here */ 8066: ); 8067: 8068: /* 8069: ** CAPI3REF: Zero Scan-Status Counters 8070: ** METHOD: sqlite3_stmt 8071: ** 8072: ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8073: ** 8074: ** This API is only available if the library is built with pre-processor 8075: ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8076: */ 8077: SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8078: 8079: /* 8080: ** CAPI3REF: Flush caches to disk mid-transaction 8081: ** 8082: ** ^If a write-transaction is open on [database connection] D when the 8083: ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8084: ** pages in the pager-cache that are not currently in use are written out 8085: ** to disk. A dirty page may be in use if a database cursor created by an 8086: ** active SQL statement is reading from it, or if it is page 1 of a database 8087: ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8088: ** interface flushes caches for all schemas - "main", "temp", and 8089: ** any [attached] databases. 8090: ** 8091: ** ^If this function needs to obtain extra database locks before dirty pages 8092: ** can be flushed to disk, it does so. ^If those locks cannot be obtained 8093: ** immediately and there is a busy-handler callback configured, it is invoked 8094: ** in the usual manner. ^If the required lock still cannot be obtained, then 8095: ** the database is skipped and an attempt made to flush any dirty pages 8096: ** belonging to the next (if any) database. ^If any databases are skipped 8097: ** because locks cannot be obtained, but no other error occurs, this 8098: ** function returns SQLITE_BUSY. 8099: ** 8100: ** ^If any other error occurs while flushing dirty pages to disk (for 8101: ** example an IO error or out-of-memory condition), then processing is 8102: ** abandoned and an SQLite [error code] is returned to the caller immediately. 8103: ** 8104: ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8105: ** 8106: ** ^This function does not set the database handle error code or message 8107: ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8108: */ 8109: SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8110: 8111: /* 8112: ** CAPI3REF: The pre-update hook. 8113: ** 8114: ** ^These interfaces are only available if SQLite is compiled using the 8115: ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8116: ** 8117: ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8118: ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8119: ** on a [rowid table]. 8120: ** ^At most one preupdate hook may be registered at a time on a single 8121: ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8122: ** the previous setting. 8123: ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8124: ** with a NULL pointer as the second parameter. 8125: ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8126: ** the first parameter to callbacks. 8127: ** 8128: ** ^The preupdate hook only fires for changes to [rowid tables]; the preupdate 8129: ** hook is not invoked for changes to [virtual tables] or [WITHOUT ROWID] 8130: ** tables. 8131: ** 8132: ** ^The second parameter to the preupdate callback is a pointer to 8133: ** the [database connection] that registered the preupdate hook. 8134: ** ^The third parameter to the preupdate callback is one of the constants 8135: ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8136: ** kind of update operation that is about to occur. 8137: ** ^(The fourth parameter to the preupdate callback is the name of the 8138: ** database within the database connection that is being modified. This 8139: ** will be "main" for the main database or "temp" for TEMP tables or 8140: ** the name given after the AS keyword in the [ATTACH] statement for attached 8141: ** databases.)^ 8142: ** ^The fifth parameter to the preupdate callback is the name of the 8143: ** table that is being modified. 8144: ** ^The sixth parameter to the preupdate callback is the initial [rowid] of the 8145: ** row being changes for SQLITE_UPDATE and SQLITE_DELETE changes and is 8146: ** undefined for SQLITE_INSERT changes. 8147: ** ^The seventh parameter to the preupdate callback is the final [rowid] of 8148: ** the row being changed for SQLITE_UPDATE and SQLITE_INSERT changes and is 8149: ** undefined for SQLITE_DELETE changes. 8150: ** 8151: ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8152: ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8153: ** provide additional information about a preupdate event. These routines 8154: ** may only be called from within a preupdate callback. Invoking any of 8155: ** these routines from outside of a preupdate callback or with a 8156: ** [database connection] pointer that is different from the one supplied 8157: ** to the preupdate callback results in undefined and probably undesirable 8158: ** behavior. 8159: ** 8160: ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8161: ** in the row that is being inserted, updated, or deleted. 8162: ** 8163: ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8164: ** a [protected sqlite3_value] that contains the value of the Nth column of 8165: ** the table row before it is updated. The N parameter must be between 0 8166: ** and one less than the number of columns or the behavior will be 8167: ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8168: ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8169: ** behavior is undefined. The [sqlite3_value] that P points to 8170: ** will be destroyed when the preupdate callback returns. 8171: ** 8172: ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8173: ** a [protected sqlite3_value] that contains the value of the Nth column of 8174: ** the table row after it is updated. The N parameter must be between 0 8175: ** and one less than the number of columns or the behavior will be 8176: ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8177: ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8178: ** behavior is undefined. The [sqlite3_value] that P points to 8179: ** will be destroyed when the preupdate callback returns. 8180: ** 8181: ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8182: ** callback was invoked as a result of a direct insert, update, or delete 8183: ** operation; or 1 for inserts, updates, or deletes invoked by top-level 8184: ** triggers; or 2 for changes resulting from triggers called by top-level 8185: ** triggers; and so forth. 8186: ** 8187: ** See also: [sqlite3_update_hook()] 8188: */ 8189: SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_preupdate_hook( 8190: sqlite3 *db, 8191: void(*xPreUpdate)( 8192: void *pCtx, /* Copy of third arg to preupdate_hook() */ 8193: sqlite3 *db, /* Database handle */ 8194: int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8195: char const *zDb, /* Database name */ 8196: char const *zName, /* Table name */ 8197: sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8198: sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8199: ), 8200: void* 8201: ); 8202: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8203: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_preupdate_count(sqlite3 *); 8204: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_preupdate_depth(sqlite3 *); 8205: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8206: 8207: /* 8208: ** CAPI3REF: Low-level system error code 8209: ** 8210: ** ^Attempt to return the underlying operating system error code or error 8211: ** number that caused the most recent I/O error or failure to open a file. 8212: ** The return value is OS-dependent. For example, on unix systems, after 8213: ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8214: ** called to get back the underlying "errno" that caused the problem, such 8215: ** as ENOSPC, EAUTH, EISDIR, and so forth. 8216: */ 8217: SQLITE_API int sqlite3_system_errno(sqlite3*); 8218: 8219: /* 8220: ** CAPI3REF: Database Snapshot 8221: ** KEYWORDS: {snapshot} 8222: ** EXPERIMENTAL 8223: ** 8224: ** An instance of the snapshot object records the state of a [WAL mode] 8225: ** database for some specific point in history. 8226: ** 8227: ** In [WAL mode], multiple [database connections] that are open on the 8228: ** same database file can each be reading a different historical version 8229: ** of the database file. When a [database connection] begins a read 8230: ** transaction, that connection sees an unchanging copy of the database 8231: ** as it existed for the point in time when the transaction first started. 8232: ** Subsequent changes to the database from other connections are not seen 8233: ** by the reader until a new read transaction is started. 8234: ** 8235: ** The sqlite3_snapshot object records state information about an historical 8236: ** version of the database file so that it is possible to later open a new read 8237: ** transaction that sees that historical version of the database rather than 8238: ** the most recent version. 8239: ** 8240: ** The constructor for this object is [sqlite3_snapshot_get()]. The 8241: ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8242: ** to an historical snapshot (if possible). The destructor for 8243: ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8244: */ 8245: typedef struct sqlite3_snapshot sqlite3_snapshot; 8246: 8247: /* 8248: ** CAPI3REF: Record A Database Snapshot 8249: ** EXPERIMENTAL 8250: ** 8251: ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8252: ** new [sqlite3_snapshot] object that records the current state of 8253: ** schema S in database connection D. ^On success, the 8254: ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8255: ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8256: ** ^If schema S of [database connection] D is not a [WAL mode] database 8257: ** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)] 8258: ** leaves the *P value unchanged and returns an appropriate [error code]. 8259: ** 8260: ** The [sqlite3_snapshot] object returned from a successful call to 8261: ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8262: ** to avoid a memory leak. 8263: ** 8264: ** The [sqlite3_snapshot_get()] interface is only available when the 8265: ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8266: */ 8267: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8268: sqlite3 *db, 8269: const char *zSchema, 8270: sqlite3_snapshot **ppSnapshot 8271: ); 8272: 8273: /* 8274: ** CAPI3REF: Start a read transaction on an historical snapshot 8275: ** EXPERIMENTAL 8276: ** 8277: ** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8278: ** read transaction for schema S of 8279: ** [database connection] D such that the read transaction 8280: ** refers to historical [snapshot] P, rather than the most 8281: ** recent change to the database. 8282: ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8283: ** or an appropriate [error code] if it fails. 8284: ** 8285: ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8286: ** the first operation following the [BEGIN] that takes the schema S 8287: ** out of [autocommit mode]. 8288: ** ^In other words, schema S must not currently be in 8289: ** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8290: ** database connection D must be out of [autocommit mode]. 8291: ** ^A [snapshot] will fail to open if it has been overwritten by a 8292: ** [checkpoint]. 8293: ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8294: ** database connection D does not know that the database file for 8295: ** schema S is in [WAL mode]. A database connection might not know 8296: ** that the database file is in [WAL mode] if there has been no prior 8297: ** I/O on that database connection, or if the database entered [WAL mode] 8298: ** after the most recent I/O on the database connection.)^ 8299: ** (Hint: Run "[PRAGMA application_id]" against a newly opened 8300: ** database connection in order to make it ready to use snapshots.) 8301: ** 8302: ** The [sqlite3_snapshot_open()] interface is only available when the 8303: ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8304: */ 8305: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8306: sqlite3 *db, 8307: const char *zSchema, 8308: sqlite3_snapshot *pSnapshot 8309: ); 8310: 8311: /* 8312: ** CAPI3REF: Destroy a snapshot 8313: ** EXPERIMENTAL 8314: ** 8315: ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8316: ** The application must eventually free every [sqlite3_snapshot] object 8317: ** using this routine to avoid a memory leak. 8318: ** 8319: ** The [sqlite3_snapshot_free()] interface is only available when the 8320: ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8321: */ 8322: SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8323: 8324: /* 8325: ** CAPI3REF: Compare the ages of two snapshot handles. 8326: ** EXPERIMENTAL 8327: ** 8328: ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8329: ** of two valid snapshot handles. 8330: ** 8331: ** If the two snapshot handles are not associated with the same database 8332: ** file, the result of the comparison is undefined. 8333: ** 8334: ** Additionally, the result of the comparison is only valid if both of the 8335: ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8336: ** last time the wal file was deleted. The wal file is deleted when the 8337: ** database is changed back to rollback mode or when the number of database 8338: ** clients drops to zero. If either snapshot handle was obtained before the 8339: ** wal file was last deleted, the value returned by this function 8340: ** is undefined. 8341: ** 8342: ** Otherwise, this API returns a negative value if P1 refers to an older 8343: ** snapshot than P2, zero if the two handles refer to the same database 8344: ** snapshot, and a positive value if P1 is a newer snapshot than P2. 8345: */ 8346: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8347: sqlite3_snapshot *p1, 8348: sqlite3_snapshot *p2 8349: ); 8350: 8351: /* 8352: ** Undo the hack that converts floating point types to integer for 8353: ** builds on processors without floating point support. 8354: */ 8355: #ifdef SQLITE_OMIT_FLOATING_POINT 8356: # undef double 8357: #endif 8358: 8359: #ifdef __cplusplus 8360: } /* End of the 'extern "C"' block */ 8361: #endif 8362: #endif /* SQLITE3_H */ 8363: 8364: /******** Begin file sqlite3rtree.h *********/ 8365: /* 8366: ** 2010 August 30 8367: ** 8368: ** The author disclaims copyright to this source code. In place of 8369: ** a legal notice, here is a blessing: 8370: ** 8371: ** May you do good and not evil. 8372: ** May you find forgiveness for yourself and forgive others. 8373: ** May you share freely, never taking more than you give. 8374: ** 8375: ************************************************************************* 8376: */ 8377: 8378: #ifndef _SQLITE3RTREE_H_ 8379: #define _SQLITE3RTREE_H_ 8380: 8381: 8382: #ifdef __cplusplus 8383: extern "C" { 8384: #endif 8385: 8386: typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8387: typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8388: 8389: /* The double-precision datatype used by RTree depends on the 8390: ** SQLITE_RTREE_INT_ONLY compile-time option. 8391: */ 8392: #ifdef SQLITE_RTREE_INT_ONLY 8393: typedef sqlite3_int64 sqlite3_rtree_dbl; 8394: #else 8395: typedef double sqlite3_rtree_dbl; 8396: #endif 8397: 8398: /* 8399: ** Register a geometry callback named zGeom that can be used as part of an 8400: ** R-Tree geometry query as follows: 8401: ** 8402: ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8403: */ 8404: SQLITE_API int sqlite3_rtree_geometry_callback( 8405: sqlite3 *db, 8406: const char *zGeom, 8407: int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8408: void *pContext 8409: ); 8410: 8411: 8412: /* 8413: ** A pointer to a structure of the following type is passed as the first 8414: ** argument to callbacks registered using rtree_geometry_callback(). 8415: */ 8416: struct sqlite3_rtree_geometry { 8417: void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8418: int nParam; /* Size of array aParam[] */ 8419: sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8420: void *pUser; /* Callback implementation user data */ 8421: void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8422: }; 8423: 8424: /* 8425: ** Register a 2nd-generation geometry callback named zScore that can be 8426: ** used as part of an R-Tree geometry query as follows: 8427: ** 8428: ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8429: */ 8430: SQLITE_API int sqlite3_rtree_query_callback( 8431: sqlite3 *db, 8432: const char *zQueryFunc, 8433: int (*xQueryFunc)(sqlite3_rtree_query_info*), 8434: void *pContext, 8435: void (*xDestructor)(void*) 8436: ); 8437: 8438: 8439: /* 8440: ** A pointer to a structure of the following type is passed as the 8441: ** argument to scored geometry callback registered using 8442: ** sqlite3_rtree_query_callback(). 8443: ** 8444: ** Note that the first 5 fields of this structure are identical to 8445: ** sqlite3_rtree_geometry. This structure is a subclass of 8446: ** sqlite3_rtree_geometry. 8447: */ 8448: struct sqlite3_rtree_query_info { 8449: void *pContext; /* pContext from when function registered */ 8450: int nParam; /* Number of function parameters */ 8451: sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8452: void *pUser; /* callback can use this, if desired */ 8453: void (*xDelUser)(void*); /* function to free pUser */ 8454: sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8455: unsigned int *anQueue; /* Number of pending entries in the queue */ 8456: int nCoord; /* Number of coordinates */ 8457: int iLevel; /* Level of current node or entry */ 8458: int mxLevel; /* The largest iLevel value in the tree */ 8459: sqlite3_int64 iRowid; /* Rowid for current entry */ 8460: sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8461: int eParentWithin; /* Visibility of parent node */ 8462: int eWithin; /* OUT: Visiblity */ 8463: sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8464: /* The following fields are only available in 3.8.11 and later */ 8465: sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8466: }; 8467: 8468: /* 8469: ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8470: */ 8471: #define NOT_WITHIN 0 /* Object completely outside of query region */ 8472: #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8473: #define FULLY_WITHIN 2 /* Object fully contained within query region */ 8474: 8475: 8476: #ifdef __cplusplus 8477: } /* end of the 'extern "C"' block */ 8478: #endif 8479: 8480: #endif /* ifndef _SQLITE3RTREE_H_ */ 8481: 8482: /******** End of sqlite3rtree.h *********/ 8483: /******** Begin file sqlite3session.h *********/ 8484: 8485: #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 8486: #define __SQLITESESSION_H_ 1 8487: 8488: /* 8489: ** Make sure we can call this stuff from C++. 8490: */ 8491: #ifdef __cplusplus 8492: extern "C" { 8493: #endif 8494: 8495: 8496: /* 8497: ** CAPI3REF: Session Object Handle 8498: */ 8499: typedef struct sqlite3_session sqlite3_session; 8500: 8501: /* 8502: ** CAPI3REF: Changeset Iterator Handle 8503: */ 8504: typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 8505: 8506: /* 8507: ** CAPI3REF: Create A New Session Object 8508: ** 8509: ** Create a new session object attached to database handle db. If successful, 8510: ** a pointer to the new object is written to *ppSession and SQLITE_OK is 8511: ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 8512: ** error code (e.g. SQLITE_NOMEM) is returned. 8513: ** 8514: ** It is possible to create multiple session objects attached to a single 8515: ** database handle. 8516: ** 8517: ** Session objects created using this function should be deleted using the 8518: ** [sqlite3session_delete()] function before the database handle that they 8519: ** are attached to is itself closed. If the database handle is closed before 8520: ** the session object is deleted, then the results of calling any session 8521: ** module function, including [sqlite3session_delete()] on the session object 8522: ** are undefined. 8523: ** 8524: ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 8525: ** is not possible for an application to register a pre-update hook on a 8526: ** database handle that has one or more session objects attached. Nor is 8527: ** it possible to create a session object attached to a database handle for 8528: ** which a pre-update hook is already defined. The results of attempting 8529: ** either of these things are undefined. 8530: ** 8531: ** The session object will be used to create changesets for tables in 8532: ** database zDb, where zDb is either "main", or "temp", or the name of an 8533: ** attached database. It is not an error if database zDb is not attached 8534: ** to the database when the session object is created. 8535: */ 8536: int sqlite3session_create( 8537: sqlite3 *db, /* Database handle */ 8538: const char *zDb, /* Name of db (e.g. "main") */ 8539: sqlite3_session **ppSession /* OUT: New session object */ 8540: ); 8541: 8542: /* 8543: ** CAPI3REF: Delete A Session Object 8544: ** 8545: ** Delete a session object previously allocated using 8546: ** [sqlite3session_create()]. Once a session object has been deleted, the 8547: ** results of attempting to use pSession with any other session module 8548: ** function are undefined. 8549: ** 8550: ** Session objects must be deleted before the database handle to which they 8551: ** are attached is closed. Refer to the documentation for 8552: ** [sqlite3session_create()] for details. 8553: */ 8554: void sqlite3session_delete(sqlite3_session *pSession); 8555: 8556: 8557: /* 8558: ** CAPI3REF: Enable Or Disable A Session Object 8559: ** 8560: ** Enable or disable the recording of changes by a session object. When 8561: ** enabled, a session object records changes made to the database. When 8562: ** disabled - it does not. A newly created session object is enabled. 8563: ** Refer to the documentation for [sqlite3session_changeset()] for further 8564: ** details regarding how enabling and disabling a session object affects 8565: ** the eventual changesets. 8566: ** 8567: ** Passing zero to this function disables the session. Passing a value 8568: ** greater than zero enables it. Passing a value less than zero is a 8569: ** no-op, and may be used to query the current state of the session. 8570: ** 8571: ** The return value indicates the final state of the session object: 0 if 8572: ** the session is disabled, or 1 if it is enabled. 8573: */ 8574: int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 8575: 8576: /* 8577: ** CAPI3REF: Set Or Clear the Indirect Change Flag 8578: ** 8579: ** Each change recorded by a session object is marked as either direct or 8580: ** indirect. A change is marked as indirect if either: 8581: ** 8582: ** <ul> 8583: ** <li> The session object "indirect" flag is set when the change is 8584: ** made, or 8585: ** <li> The change is made by an SQL trigger or foreign key action 8586: ** instead of directly as a result of a users SQL statement. 8587: ** </ul> 8588: ** 8589: ** If a single row is affected by more than one operation within a session, 8590: ** then the change is considered indirect if all operations meet the criteria 8591: ** for an indirect change above, or direct otherwise. 8592: ** 8593: ** This function is used to set, clear or query the session object indirect 8594: ** flag. If the second argument passed to this function is zero, then the 8595: ** indirect flag is cleared. If it is greater than zero, the indirect flag 8596: ** is set. Passing a value less than zero does not modify the current value 8597: ** of the indirect flag, and may be used to query the current state of the 8598: ** indirect flag for the specified session object. 8599: ** 8600: ** The return value indicates the final state of the indirect flag: 0 if 8601: ** it is clear, or 1 if it is set. 8602: */ 8603: int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 8604: 8605: /* 8606: ** CAPI3REF: Attach A Table To A Session Object 8607: ** 8608: ** If argument zTab is not NULL, then it is the name of a table to attach 8609: ** to the session object passed as the first argument. All subsequent changes 8610: ** made to the table while the session object is enabled will be recorded. See 8611: ** documentation for [sqlite3session_changeset()] for further details. 8612: ** 8613: ** Or, if argument zTab is NULL, then changes are recorded for all tables 8614: ** in the database. If additional tables are added to the database (by 8615: ** executing "CREATE TABLE" statements) after this call is made, changes for 8616: ** the new tables are also recorded. 8617: ** 8618: ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 8619: ** defined as part of their CREATE TABLE statement. It does not matter if the 8620: ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 8621: ** KEY may consist of a single column, or may be a composite key. 8622: ** 8623: ** It is not an error if the named table does not exist in the database. Nor 8624: ** is it an error if the named table does not have a PRIMARY KEY. However, 8625: ** no changes will be recorded in either of these scenarios. 8626: ** 8627: ** Changes are not recorded for individual rows that have NULL values stored 8628: ** in one or more of their PRIMARY KEY columns. 8629: ** 8630: ** SQLITE_OK is returned if the call completes without error. Or, if an error 8631: ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 8632: */ 8633: int sqlite3session_attach( 8634: sqlite3_session *pSession, /* Session object */ 8635: const char *zTab /* Table name */ 8636: ); 8637: 8638: /* 8639: ** CAPI3REF: Set a table filter on a Session Object. 8640: ** 8641: ** The second argument (xFilter) is the "filter callback". For changes to rows 8642: ** in tables that are not attached to the Session oject, the filter is called 8643: ** to determine whether changes to the table's rows should be tracked or not. 8644: ** If xFilter returns 0, changes is not tracked. Note that once a table is 8645: ** attached, xFilter will not be called again. 8646: */ 8647: void sqlite3session_table_filter( 8648: sqlite3_session *pSession, /* Session object */ 8649: int(*xFilter)( 8650: void *pCtx, /* Copy of third arg to _filter_table() */ 8651: const char *zTab /* Table name */ 8652: ), 8653: void *pCtx /* First argument passed to xFilter */ 8654: ); 8655: 8656: /* 8657: ** CAPI3REF: Generate A Changeset From A Session Object 8658: ** 8659: ** Obtain a changeset containing changes to the tables attached to the 8660: ** session object passed as the first argument. If successful, 8661: ** set *ppChangeset to point to a buffer containing the changeset 8662: ** and *pnChangeset to the size of the changeset in bytes before returning 8663: ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 8664: ** zero and return an SQLite error code. 8665: ** 8666: ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 8667: ** each representing a change to a single row of an attached table. An INSERT 8668: ** change contains the values of each field of a new database row. A DELETE 8669: ** contains the original values of each field of a deleted database row. An 8670: ** UPDATE change contains the original values of each field of an updated 8671: ** database row along with the updated values for each updated non-primary-key 8672: ** column. It is not possible for an UPDATE change to represent a change that 8673: ** modifies the values of primary key columns. If such a change is made, it 8674: ** is represented in a changeset as a DELETE followed by an INSERT. 8675: ** 8676: ** Changes are not recorded for rows that have NULL values stored in one or 8677: ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 8678: ** no corresponding change is present in the changesets returned by this 8679: ** function. If an existing row with one or more NULL values stored in 8680: ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 8681: ** only an INSERT is appears in the changeset. Similarly, if an existing row 8682: ** with non-NULL PRIMARY KEY values is updated so that one or more of its 8683: ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 8684: ** DELETE change only. 8685: ** 8686: ** The contents of a changeset may be traversed using an iterator created 8687: ** using the [sqlite3changeset_start()] API. A changeset may be applied to 8688: ** a database with a compatible schema using the [sqlite3changeset_apply()] 8689: ** API. 8690: ** 8691: ** Within a changeset generated by this function, all changes related to a 8692: ** single table are grouped together. In other words, when iterating through 8693: ** a changeset or when applying a changeset to a database, all changes related 8694: ** to a single table are processed before moving on to the next table. Tables 8695: ** are sorted in the same order in which they were attached (or auto-attached) 8696: ** to the sqlite3_session object. The order in which the changes related to 8697: ** a single table are stored is undefined. 8698: ** 8699: ** Following a successful call to this function, it is the responsibility of 8700: ** the caller to eventually free the buffer that *ppChangeset points to using 8701: ** [sqlite3_free()]. 8702: ** 8703: ** <h3>Changeset Generation</h3> 8704: ** 8705: ** Once a table has been attached to a session object, the session object 8706: ** records the primary key values of all new rows inserted into the table. 8707: ** It also records the original primary key and other column values of any 8708: ** deleted or updated rows. For each unique primary key value, data is only 8709: ** recorded once - the first time a row with said primary key is inserted, 8710: ** updated or deleted in the lifetime of the session. 8711: ** 8712: ** There is one exception to the previous paragraph: when a row is inserted, 8713: ** updated or deleted, if one or more of its primary key columns contain a 8714: ** NULL value, no record of the change is made. 8715: ** 8716: ** The session object therefore accumulates two types of records - those 8717: ** that consist of primary key values only (created when the user inserts 8718: ** a new record) and those that consist of the primary key values and the 8719: ** original values of other table columns (created when the users deletes 8720: ** or updates a record). 8721: ** 8722: ** When this function is called, the requested changeset is created using 8723: ** both the accumulated records and the current contents of the database 8724: ** file. Specifically: 8725: ** 8726: ** <ul> 8727: ** <li> For each record generated by an insert, the database is queried 8728: ** for a row with a matching primary key. If one is found, an INSERT 8729: ** change is added to the changeset. If no such row is found, no change 8730: ** is added to the changeset. 8731: ** 8732: ** <li> For each record generated by an update or delete, the database is 8733: ** queried for a row with a matching primary key. If such a row is 8734: ** found and one or more of the non-primary key fields have been 8735: ** modified from their original values, an UPDATE change is added to 8736: ** the changeset. Or, if no such row is found in the table, a DELETE 8737: ** change is added to the changeset. If there is a row with a matching 8738: ** primary key in the database, but all fields contain their original 8739: ** values, no change is added to the changeset. 8740: ** </ul> 8741: ** 8742: ** This means, amongst other things, that if a row is inserted and then later 8743: ** deleted while a session object is active, neither the insert nor the delete 8744: ** will be present in the changeset. Or if a row is deleted and then later a 8745: ** row with the same primary key values inserted while a session object is 8746: ** active, the resulting changeset will contain an UPDATE change instead of 8747: ** a DELETE and an INSERT. 8748: ** 8749: ** When a session object is disabled (see the [sqlite3session_enable()] API), 8750: ** it does not accumulate records when rows are inserted, updated or deleted. 8751: ** This may appear to have some counter-intuitive effects if a single row 8752: ** is written to more than once during a session. For example, if a row 8753: ** is inserted while a session object is enabled, then later deleted while 8754: ** the same session object is disabled, no INSERT record will appear in the 8755: ** changeset, even though the delete took place while the session was disabled. 8756: ** Or, if one field of a row is updated while a session is disabled, and 8757: ** another field of the same row is updated while the session is enabled, the 8758: ** resulting changeset will contain an UPDATE change that updates both fields. 8759: */ 8760: int sqlite3session_changeset( 8761: sqlite3_session *pSession, /* Session object */ 8762: int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 8763: void **ppChangeset /* OUT: Buffer containing changeset */ 8764: ); 8765: 8766: /* 8767: ** CAPI3REF: Load The Difference Between Tables Into A Session 8768: ** 8769: ** If it is not already attached to the session object passed as the first 8770: ** argument, this function attaches table zTbl in the same manner as the 8771: ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 8772: ** does not have a primary key, this function is a no-op (but does not return 8773: ** an error). 8774: ** 8775: ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 8776: ** attached to the same database handle as the session object that contains 8777: ** a table compatible with the table attached to the session by this function. 8778: ** A table is considered compatible if it: 8779: ** 8780: ** <ul> 8781: ** <li> Has the same name, 8782: ** <li> Has the same set of columns declared in the same order, and 8783: ** <li> Has the same PRIMARY KEY definition. 8784: ** </ul> 8785: ** 8786: ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 8787: ** are compatible but do not have any PRIMARY KEY columns, it is not an error 8788: ** but no changes are added to the session object. As with other session 8789: ** APIs, tables without PRIMARY KEYs are simply ignored. 8790: ** 8791: ** This function adds a set of changes to the session object that could be 8792: ** used to update the table in database zFrom (call this the "from-table") 8793: ** so that its content is the same as the table attached to the session 8794: ** object (call this the "to-table"). Specifically: 8795: ** 8796: ** <ul> 8797: ** <li> For each row (primary key) that exists in the to-table but not in 8798: ** the from-table, an INSERT record is added to the session object. 8799: ** 8800: ** <li> For each row (primary key) that exists in the to-table but not in 8801: ** the from-table, a DELETE record is added to the session object. 8802: ** 8803: ** <li> For each row (primary key) that exists in both tables, but features 8804: ** different in each, an UPDATE record is added to the session. 8805: ** </ul> 8806: ** 8807: ** To clarify, if this function is called and then a changeset constructed 8808: ** using [sqlite3session_changeset()], then after applying that changeset to 8809: ** database zFrom the contents of the two compatible tables would be 8810: ** identical. 8811: ** 8812: ** It an error if database zFrom does not exist or does not contain the 8813: ** required compatible table. 8814: ** 8815: ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 8816: ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 8817: ** may be set to point to a buffer containing an English language error 8818: ** message. It is the responsibility of the caller to free this buffer using 8819: ** sqlite3_free(). 8820: */ 8821: int sqlite3session_diff( 8822: sqlite3_session *pSession, 8823: const char *zFromDb, 8824: const char *zTbl, 8825: char **pzErrMsg 8826: ); 8827: 8828: 8829: /* 8830: ** CAPI3REF: Generate A Patchset From A Session Object 8831: ** 8832: ** The differences between a patchset and a changeset are that: 8833: ** 8834: ** <ul> 8835: ** <li> DELETE records consist of the primary key fields only. The 8836: ** original values of other fields are omitted. 8837: ** <li> The original values of any modified fields are omitted from 8838: ** UPDATE records. 8839: ** </ul> 8840: ** 8841: ** A patchset blob may be used with up to date versions of all 8842: ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 8843: ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 8844: ** attempting to use a patchset blob with old versions of the 8845: ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 8846: ** 8847: ** Because the non-primary key "old.*" fields are omitted, no 8848: ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 8849: ** is passed to the sqlite3changeset_apply() API. Other conflict types work 8850: ** in the same way as for changesets. 8851: ** 8852: ** Changes within a patchset are ordered in the same way as for changesets 8853: ** generated by the sqlite3session_changeset() function (i.e. all changes for 8854: ** a single table are grouped together, tables appear in the order in which 8855: ** they were attached to the session object). 8856: */ 8857: int sqlite3session_patchset( 8858: sqlite3_session *pSession, /* Session object */ 8859: int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */ 8860: void **ppPatchset /* OUT: Buffer containing changeset */ 8861: ); 8862: 8863: /* 8864: ** CAPI3REF: Test if a changeset has recorded any changes. 8865: ** 8866: ** Return non-zero if no changes to attached tables have been recorded by 8867: ** the session object passed as the first argument. Otherwise, if one or 8868: ** more changes have been recorded, return zero. 8869: ** 8870: ** Even if this function returns zero, it is possible that calling 8871: ** [sqlite3session_changeset()] on the session handle may still return a 8872: ** changeset that contains no changes. This can happen when a row in 8873: ** an attached table is modified and then later on the original values 8874: ** are restored. However, if this function returns non-zero, then it is 8875: ** guaranteed that a call to sqlite3session_changeset() will return a 8876: ** changeset containing zero changes. 8877: */ 8878: int sqlite3session_isempty(sqlite3_session *pSession); 8879: 8880: /* 8881: ** CAPI3REF: Create An Iterator To Traverse A Changeset 8882: ** 8883: ** Create an iterator used to iterate through the contents of a changeset. 8884: ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 8885: ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 8886: ** SQLite error code is returned. 8887: ** 8888: ** The following functions can be used to advance and query a changeset 8889: ** iterator created by this function: 8890: ** 8891: ** <ul> 8892: ** <li> [sqlite3changeset_next()] 8893: ** <li> [sqlite3changeset_op()] 8894: ** <li> [sqlite3changeset_new()] 8895: ** <li> [sqlite3changeset_old()] 8896: ** </ul> 8897: ** 8898: ** It is the responsibility of the caller to eventually destroy the iterator 8899: ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 8900: ** changeset (pChangeset) must remain valid until after the iterator is 8901: ** destroyed. 8902: ** 8903: ** Assuming the changeset blob was created by one of the 8904: ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 8905: ** [sqlite3changeset_invert()] functions, all changes within the changeset 8906: ** that apply to a single table are grouped together. This means that when 8907: ** an application iterates through a changeset using an iterator created by 8908: ** this function, all changes that relate to a single table are visted 8909: ** consecutively. There is no chance that the iterator will visit a change 8910: ** the applies to table X, then one for table Y, and then later on visit 8911: ** another change for table X. 8912: */ 8913: int sqlite3changeset_start( 8914: sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 8915: int nChangeset, /* Size of changeset blob in bytes */ 8916: void *pChangeset /* Pointer to blob containing changeset */ 8917: ); 8918: 8919: 8920: /* 8921: ** CAPI3REF: Advance A Changeset Iterator 8922: ** 8923: ** This function may only be used with iterators created by function 8924: ** [sqlite3changeset_start()]. If it is called on an iterator passed to 8925: ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 8926: ** is returned and the call has no effect. 8927: ** 8928: ** Immediately after an iterator is created by sqlite3changeset_start(), it 8929: ** does not point to any change in the changeset. Assuming the changeset 8930: ** is not empty, the first call to this function advances the iterator to 8931: ** point to the first change in the changeset. Each subsequent call advances 8932: ** the iterator to point to the next change in the changeset (if any). If 8933: ** no error occurs and the iterator points to a valid change after a call 8934: ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 8935: ** Otherwise, if all changes in the changeset have already been visited, 8936: ** SQLITE_DONE is returned. 8937: ** 8938: ** If an error occurs, an SQLite error code is returned. Possible error 8939: ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 8940: ** SQLITE_NOMEM. 8941: */ 8942: int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 8943: 8944: /* 8945: ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 8946: ** 8947: ** The pIter argument passed to this function may either be an iterator 8948: ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 8949: ** created by [sqlite3changeset_start()]. In the latter case, the most recent 8950: ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 8951: ** is not the case, this function returns [SQLITE_MISUSE]. 8952: ** 8953: ** If argument pzTab is not NULL, then *pzTab is set to point to a 8954: ** nul-terminated utf-8 encoded string containing the name of the table 8955: ** affected by the current change. The buffer remains valid until either 8956: ** sqlite3changeset_next() is called on the iterator or until the 8957: ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 8958: ** set to the number of columns in the table affected by the change. If 8959: ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 8960: ** is an indirect change, or false (0) otherwise. See the documentation for 8961: ** [sqlite3session_indirect()] for a description of direct and indirect 8962: ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 8963: ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 8964: ** type of change that the iterator currently points to. 8965: ** 8966: ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 8967: ** SQLite error code is returned. The values of the output variables may not 8968: ** be trusted in this case. 8969: */ 8970: int sqlite3changeset_op( 8971: sqlite3_changeset_iter *pIter, /* Iterator object */ 8972: const char **pzTab, /* OUT: Pointer to table name */ 8973: int *pnCol, /* OUT: Number of columns in table */ 8974: int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 8975: int *pbIndirect /* OUT: True for an 'indirect' change */ 8976: ); 8977: 8978: /* 8979: ** CAPI3REF: Obtain The Primary Key Definition Of A Table 8980: ** 8981: ** For each modified table, a changeset includes the following: 8982: ** 8983: ** <ul> 8984: ** <li> The number of columns in the table, and 8985: ** <li> Which of those columns make up the tables PRIMARY KEY. 8986: ** </ul> 8987: ** 8988: ** This function is used to find which columns comprise the PRIMARY KEY of 8989: ** the table modified by the change that iterator pIter currently points to. 8990: ** If successful, *pabPK is set to point to an array of nCol entries, where 8991: ** nCol is the number of columns in the table. Elements of *pabPK are set to 8992: ** 0x01 if the corresponding column is part of the tables primary key, or 8993: ** 0x00 if it is not. 8994: ** 8995: ** If argumet pnCol is not NULL, then *pnCol is set to the number of columns 8996: ** in the table. 8997: ** 8998: ** If this function is called when the iterator does not point to a valid 8999: ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9000: ** SQLITE_OK is returned and the output variables populated as described 9001: ** above. 9002: */ 9003: int sqlite3changeset_pk( 9004: sqlite3_changeset_iter *pIter, /* Iterator object */ 9005: unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9006: int *pnCol /* OUT: Number of entries in output array */ 9007: ); 9008: 9009: /* 9010: ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9011: ** 9012: ** The pIter argument passed to this function may either be an iterator 9013: ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9014: ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9015: ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9016: ** Furthermore, it may only be called if the type of change that the iterator 9017: ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9018: ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9019: ** 9020: ** Argument iVal must be greater than or equal to 0, and less than the number 9021: ** of columns in the table affected by the current change. Otherwise, 9022: ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9023: ** 9024: ** If successful, this function sets *ppValue to point to a protected 9025: ** sqlite3_value object containing the iVal'th value from the vector of 9026: ** original row values stored as part of the UPDATE or DELETE change and 9027: ** returns SQLITE_OK. The name of the function comes from the fact that this 9028: ** is similar to the "old.*" columns available to update or delete triggers. 9029: ** 9030: ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9031: ** is returned and *ppValue is set to NULL. 9032: */ 9033: int sqlite3changeset_old( 9034: sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9035: int iVal, /* Column number */ 9036: sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 9037: ); 9038: 9039: /* 9040: ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 9041: ** 9042: ** The pIter argument passed to this function may either be an iterator 9043: ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9044: ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9045: ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9046: ** Furthermore, it may only be called if the type of change that the iterator 9047: ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 9048: ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9049: ** 9050: ** Argument iVal must be greater than or equal to 0, and less than the number 9051: ** of columns in the table affected by the current change. Otherwise, 9052: ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9053: ** 9054: ** If successful, this function sets *ppValue to point to a protected 9055: ** sqlite3_value object containing the iVal'th value from the vector of 9056: ** new row values stored as part of the UPDATE or INSERT change and 9057: ** returns SQLITE_OK. If the change is an UPDATE and does not include 9058: ** a new value for the requested column, *ppValue is set to NULL and 9059: ** SQLITE_OK returned. The name of the function comes from the fact that 9060: ** this is similar to the "new.*" columns available to update or delete 9061: ** triggers. 9062: ** 9063: ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9064: ** is returned and *ppValue is set to NULL. 9065: */ 9066: int sqlite3changeset_new( 9067: sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9068: int iVal, /* Column number */ 9069: sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 9070: ); 9071: 9072: /* 9073: ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 9074: ** 9075: ** This function should only be used with iterator objects passed to a 9076: ** conflict-handler callback by [sqlite3changeset_apply()] with either 9077: ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 9078: ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 9079: ** is set to NULL. 9080: ** 9081: ** Argument iVal must be greater than or equal to 0, and less than the number 9082: ** of columns in the table affected by the current change. Otherwise, 9083: ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9084: ** 9085: ** If successful, this function sets *ppValue to point to a protected 9086: ** sqlite3_value object containing the iVal'th value from the 9087: ** "conflicting row" associated with the current conflict-handler callback 9088: ** and returns SQLITE_OK. 9089: ** 9090: ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9091: ** is returned and *ppValue is set to NULL. 9092: */ 9093: int sqlite3changeset_conflict( 9094: sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9095: int iVal, /* Column number */ 9096: sqlite3_value **ppValue /* OUT: Value from conflicting row */ 9097: ); 9098: 9099: /* 9100: ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 9101: ** 9102: ** This function may only be called with an iterator passed to an 9103: ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 9104: ** it sets the output variable to the total number of known foreign key 9105: ** violations in the destination database and returns SQLITE_OK. 9106: ** 9107: ** In all other cases this function returns SQLITE_MISUSE. 9108: */ 9109: int sqlite3changeset_fk_conflicts( 9110: sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9111: int *pnOut /* OUT: Number of FK violations */ 9112: ); 9113: 9114: 9115: /* 9116: ** CAPI3REF: Finalize A Changeset Iterator 9117: ** 9118: ** This function is used to finalize an iterator allocated with 9119: ** [sqlite3changeset_start()]. 9120: ** 9121: ** This function should only be called on iterators created using the 9122: ** [sqlite3changeset_start()] function. If an application calls this 9123: ** function with an iterator passed to a conflict-handler by 9124: ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 9125: ** call has no effect. 9126: ** 9127: ** If an error was encountered within a call to an sqlite3changeset_xxx() 9128: ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 9129: ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 9130: ** to that error is returned by this function. Otherwise, SQLITE_OK is 9131: ** returned. This is to allow the following pattern (pseudo-code): 9132: ** 9133: ** sqlite3changeset_start(); 9134: ** while( SQLITE_ROW==sqlite3changeset_next() ){ 9135: ** // Do something with change. 9136: ** } 9137: ** rc = sqlite3changeset_finalize(); 9138: ** if( rc!=SQLITE_OK ){ 9139: ** // An error has occurred 9140: ** } 9141: */ 9142: int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 9143: 9144: /* 9145: ** CAPI3REF: Invert A Changeset 9146: ** 9147: ** This function is used to "invert" a changeset object. Applying an inverted 9148: ** changeset to a database reverses the effects of applying the uninverted 9149: ** changeset. Specifically: 9150: ** 9151: ** <ul> 9152: ** <li> Each DELETE change is changed to an INSERT, and 9153: ** <li> Each INSERT change is changed to a DELETE, and 9154: ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 9155: ** </ul> 9156: ** 9157: ** This function does not change the order in which changes appear within 9158: ** the changeset. It merely reverses the sense of each individual change. 9159: ** 9160: ** If successful, a pointer to a buffer containing the inverted changeset 9161: ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 9162: ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 9163: ** zeroed and an SQLite error code returned. 9164: ** 9165: ** It is the responsibility of the caller to eventually call sqlite3_free() 9166: ** on the *ppOut pointer to free the buffer allocation following a successful 9167: ** call to this function. 9168: ** 9169: ** WARNING/TODO: This function currently assumes that the input is a valid 9170: ** changeset. If it is not, the results are undefined. 9171: */ 9172: int sqlite3changeset_invert( 9173: int nIn, const void *pIn, /* Input changeset */ 9174: int *pnOut, void **ppOut /* OUT: Inverse of input */ 9175: ); 9176: 9177: /* 9178: ** CAPI3REF: Concatenate Two Changeset Objects 9179: ** 9180: ** This function is used to concatenate two changesets, A and B, into a 9181: ** single changeset. The result is a changeset equivalent to applying 9182: ** changeset A followed by changeset B. 9183: ** 9184: ** This function combines the two input changesets using an 9185: ** sqlite3_changegroup object. Calling it produces similar results as the 9186: ** following code fragment: 9187: ** 9188: ** sqlite3_changegroup *pGrp; 9189: ** rc = sqlite3_changegroup_new(&pGrp); 9190: ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 9191: ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 9192: ** if( rc==SQLITE_OK ){ 9193: ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 9194: ** }else{ 9195: ** *ppOut = 0; 9196: ** *pnOut = 0; 9197: ** } 9198: ** 9199: ** Refer to the sqlite3_changegroup documentation below for details. 9200: */ 9201: int sqlite3changeset_concat( 9202: int nA, /* Number of bytes in buffer pA */ 9203: void *pA, /* Pointer to buffer containing changeset A */ 9204: int nB, /* Number of bytes in buffer pB */ 9205: void *pB, /* Pointer to buffer containing changeset B */ 9206: int *pnOut, /* OUT: Number of bytes in output changeset */ 9207: void **ppOut /* OUT: Buffer containing output changeset */ 9208: ); 9209: 9210: 9211: /* 9212: ** Changegroup handle. 9213: */ 9214: typedef struct sqlite3_changegroup sqlite3_changegroup; 9215: 9216: /* 9217: ** CAPI3REF: Combine two or more changesets into a single changeset. 9218: ** 9219: ** An sqlite3_changegroup object is used to combine two or more changesets 9220: ** (or patchsets) into a single changeset (or patchset). A single changegroup 9221: ** object may combine changesets or patchsets, but not both. The output is 9222: ** always in the same format as the input. 9223: ** 9224: ** If successful, this function returns SQLITE_OK and populates (*pp) with 9225: ** a pointer to a new sqlite3_changegroup object before returning. The caller 9226: ** should eventually free the returned object using a call to 9227: ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 9228: ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 9229: ** 9230: ** The usual usage pattern for an sqlite3_changegroup object is as follows: 9231: ** 9232: ** <ul> 9233: ** <li> It is created using a call to sqlite3changegroup_new(). 9234: ** 9235: ** <li> Zero or more changesets (or patchsets) are added to the object 9236: ** by calling sqlite3changegroup_add(). 9237: ** 9238: ** <li> The result of combining all input changesets together is obtained 9239: ** by the application via a call to sqlite3changegroup_output(). 9240: ** 9241: ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 9242: ** </ul> 9243: ** 9244: ** Any number of calls to add() and output() may be made between the calls to 9245: ** new() and delete(), and in any order. 9246: ** 9247: ** As well as the regular sqlite3changegroup_add() and 9248: ** sqlite3changegroup_output() functions, also available are the streaming 9249: ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 9250: */ 9251: int sqlite3changegroup_new(sqlite3_changegroup **pp); 9252: 9253: /* 9254: ** Add all changes within the changeset (or patchset) in buffer pData (size 9255: ** nData bytes) to the changegroup. 9256: ** 9257: ** If the buffer contains a patchset, then all prior calls to this function 9258: ** on the same changegroup object must also have specified patchsets. Or, if 9259: ** the buffer contains a changeset, so must have the earlier calls to this 9260: ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 9261: ** to the changegroup. 9262: ** 9263: ** Rows within the changeset and changegroup are identified by the values in 9264: ** their PRIMARY KEY columns. A change in the changeset is considered to 9265: ** apply to the same row as a change already present in the changegroup if 9266: ** the two rows have the same primary key. 9267: ** 9268: ** Changes to rows that that do not already appear in the changegroup are 9269: ** simply copied into it. Or, if both the new changeset and the changegroup 9270: ** contain changes that apply to a single row, the final contents of the 9271: ** changegroup depends on the type of each change, as follows: 9272: ** 9273: ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9274: ** <tr><th style="white-space:pre">Existing Change </th> 9275: ** <th style="white-space:pre">New Change </th> 9276: ** <th>Output Change 9277: ** <tr><td>INSERT <td>INSERT <td> 9278: ** The new change is ignored. This case does not occur if the new 9279: ** changeset was recorded immediately after the changesets already 9280: ** added to the changegroup. 9281: ** <tr><td>INSERT <td>UPDATE <td> 9282: ** The INSERT change remains in the changegroup. The values in the 9283: ** INSERT change are modified as if the row was inserted by the 9284: ** existing change and then updated according to the new change. 9285: ** <tr><td>INSERT <td>DELETE <td> 9286: ** The existing INSERT is removed from the changegroup. The DELETE is 9287: ** not added. 9288: ** <tr><td>UPDATE <td>INSERT <td> 9289: ** The new change is ignored. This case does not occur if the new 9290: ** changeset was recorded immediately after the changesets already 9291: ** added to the changegroup. 9292: ** <tr><td>UPDATE <td>UPDATE <td> 9293: ** The existing UPDATE remains within the changegroup. It is amended 9294: ** so that the accompanying values are as if the row was updated once 9295: ** by the existing change and then again by the new change. 9296: ** <tr><td>UPDATE <td>DELETE <td> 9297: ** The existing UPDATE is replaced by the new DELETE within the 9298: ** changegroup. 9299: ** <tr><td>DELETE <td>INSERT <td> 9300: ** If one or more of the column values in the row inserted by the 9301: ** new change differ from those in the row deleted by the existing 9302: ** change, the existing DELETE is replaced by an UPDATE within the 9303: ** changegroup. Otherwise, if the inserted row is exactly the same 9304: ** as the deleted row, the existing DELETE is simply discarded. 9305: ** <tr><td>DELETE <td>UPDATE <td> 9306: ** The new change is ignored. This case does not occur if the new 9307: ** changeset was recorded immediately after the changesets already 9308: ** added to the changegroup. 9309: ** <tr><td>DELETE <td>DELETE <td> 9310: ** The new change is ignored. This case does not occur if the new 9311: ** changeset was recorded immediately after the changesets already 9312: ** added to the changegroup. 9313: ** </table> 9314: ** 9315: ** If the new changeset contains changes to a table that is already present 9316: ** in the changegroup, then the number of columns and the position of the 9317: ** primary key columns for the table must be consistent. If this is not the 9318: ** case, this function fails with SQLITE_SCHEMA. If the input changeset 9319: ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 9320: ** returned. Or, if an out-of-memory condition occurs during processing, this 9321: ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 9322: ** final contents of the changegroup is undefined. 9323: ** 9324: ** If no error occurs, SQLITE_OK is returned. 9325: */ 9326: int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 9327: 9328: /* 9329: ** Obtain a buffer containing a changeset (or patchset) representing the 9330: ** current contents of the changegroup. If the inputs to the changegroup 9331: ** were themselves changesets, the output is a changeset. Or, if the 9332: ** inputs were patchsets, the output is also a patchset. 9333: ** 9334: ** As with the output of the sqlite3session_changeset() and 9335: ** sqlite3session_patchset() functions, all changes related to a single 9336: ** table are grouped together in the output of this function. Tables appear 9337: ** in the same order as for the very first changeset added to the changegroup. 9338: ** If the second or subsequent changesets added to the changegroup contain 9339: ** changes for tables that do not appear in the first changeset, they are 9340: ** appended onto the end of the output changeset, again in the order in 9341: ** which they are first encountered. 9342: ** 9343: ** If an error occurs, an SQLite error code is returned and the output 9344: ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 9345: ** is returned and the output variables are set to the size of and a 9346: ** pointer to the output buffer, respectively. In this case it is the 9347: ** responsibility of the caller to eventually free the buffer using a 9348: ** call to sqlite3_free(). 9349: */ 9350: int sqlite3changegroup_output( 9351: sqlite3_changegroup*, 9352: int *pnData, /* OUT: Size of output buffer in bytes */ 9353: void **ppData /* OUT: Pointer to output buffer */ 9354: ); 9355: 9356: /* 9357: ** Delete a changegroup object. 9358: */ 9359: void sqlite3changegroup_delete(sqlite3_changegroup*); 9360: 9361: /* 9362: ** CAPI3REF: Apply A Changeset To A Database 9363: ** 9364: ** Apply a changeset to a database. This function attempts to update the 9365: ** "main" database attached to handle db with the changes found in the 9366: ** changeset passed via the second and third arguments. 9367: ** 9368: ** The fourth argument (xFilter) passed to this function is the "filter 9369: ** callback". If it is not NULL, then for each table affected by at least one 9370: ** change in the changeset, the filter callback is invoked with 9371: ** the table name as the second argument, and a copy of the context pointer 9372: ** passed as the sixth argument to this function as the first. If the "filter 9373: ** callback" returns zero, then no attempt is made to apply any changes to 9374: ** the table. Otherwise, if the return value is non-zero or the xFilter 9375: ** argument to this function is NULL, all changes related to the table are 9376: ** attempted. 9377: ** 9378: ** For each table that is not excluded by the filter callback, this function 9379: ** tests that the target database contains a compatible table. A table is 9380: ** considered compatible if all of the following are true: 9381: ** 9382: ** <ul> 9383: ** <li> The table has the same name as the name recorded in the 9384: ** changeset, and 9385: ** <li> The table has the same number of columns as recorded in the 9386: ** changeset, and 9387: ** <li> The table has primary key columns in the same position as 9388: ** recorded in the changeset. 9389: ** </ul> 9390: ** 9391: ** If there is no compatible table, it is not an error, but none of the 9392: ** changes associated with the table are applied. A warning message is issued 9393: ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 9394: ** one such warning is issued for each table in the changeset. 9395: ** 9396: ** For each change for which there is a compatible table, an attempt is made 9397: ** to modify the table contents according to the UPDATE, INSERT or DELETE 9398: ** change. If a change cannot be applied cleanly, the conflict handler 9399: ** function passed as the fifth argument to sqlite3changeset_apply() may be 9400: ** invoked. A description of exactly when the conflict handler is invoked for 9401: ** each type of change is below. 9402: ** 9403: ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 9404: ** of passing anything other than a valid function pointer as the xConflict 9405: ** argument are undefined. 9406: ** 9407: ** Each time the conflict handler function is invoked, it must return one 9408: ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 9409: ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 9410: ** if the second argument passed to the conflict handler is either 9411: ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 9412: ** returns an illegal value, any changes already made are rolled back and 9413: ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 9414: ** actions are taken by sqlite3changeset_apply() depending on the value 9415: ** returned by each invocation of the conflict-handler function. Refer to 9416: ** the documentation for the three 9417: ** [SQLITE_CHANGESET_OMIT|available return values] for details. 9418: ** 9419: ** <dl> 9420: ** <dt>DELETE Changes<dd> 9421: ** For each DELETE change, this function checks if the target database 9422: ** contains a row with the same primary key value (or values) as the 9423: ** original row values stored in the changeset. If it does, and the values 9424: ** stored in all non-primary key columns also match the values stored in 9425: ** the changeset the row is deleted from the target database. 9426: ** 9427: ** If a row with matching primary key values is found, but one or more of 9428: ** the non-primary key fields contains a value different from the original 9429: ** row value stored in the changeset, the conflict-handler function is 9430: ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. 9431: ** 9432: ** If no row with matching primary key values is found in the database, 9433: ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9434: ** passed as the second argument. 9435: ** 9436: ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 9437: ** (which can only happen if a foreign key constraint is violated), the 9438: ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 9439: ** passed as the second argument. This includes the case where the DELETE 9440: ** operation is attempted because an earlier call to the conflict handler 9441: ** function returned [SQLITE_CHANGESET_REPLACE]. 9442: ** 9443: ** <dt>INSERT Changes<dd> 9444: ** For each INSERT change, an attempt is made to insert the new row into 9445: ** the database. 9446: ** 9447: ** If the attempt to insert the row fails because the database already 9448: ** contains a row with the same primary key values, the conflict handler 9449: ** function is invoked with the second argument set to 9450: ** [SQLITE_CHANGESET_CONFLICT]. 9451: ** 9452: ** If the attempt to insert the row fails because of some other constraint 9453: ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 9454: ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 9455: ** This includes the case where the INSERT operation is re-attempted because 9456: ** an earlier call to the conflict handler function returned 9457: ** [SQLITE_CHANGESET_REPLACE]. 9458: ** 9459: ** <dt>UPDATE Changes<dd> 9460: ** For each UPDATE change, this function checks if the target database 9461: ** contains a row with the same primary key value (or values) as the 9462: ** original row values stored in the changeset. If it does, and the values 9463: ** stored in all non-primary key columns also match the values stored in 9464: ** the changeset the row is updated within the target database. 9465: ** 9466: ** If a row with matching primary key values is found, but one or more of 9467: ** the non-primary key fields contains a value different from an original 9468: ** row value stored in the changeset, the conflict-handler function is 9469: ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 9470: ** UPDATE changes only contain values for non-primary key fields that are 9471: ** to be modified, only those fields need to match the original values to 9472: ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 9473: ** 9474: ** If no row with matching primary key values is found in the database, 9475: ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9476: ** passed as the second argument. 9477: ** 9478: ** If the UPDATE operation is attempted, but SQLite returns 9479: ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 9480: ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 9481: ** This includes the case where the UPDATE operation is attempted after 9482: ** an earlier call to the conflict handler function returned 9483: ** [SQLITE_CHANGESET_REPLACE]. 9484: ** </dl> 9485: ** 9486: ** It is safe to execute SQL statements, including those that write to the 9487: ** table that the callback related to, from within the xConflict callback. 9488: ** This can be used to further customize the applications conflict 9489: ** resolution strategy. 9490: ** 9491: ** All changes made by this function are enclosed in a savepoint transaction. 9492: ** If any other error (aside from a constraint failure when attempting to 9493: ** write to the target database) occurs, then the savepoint transaction is 9494: ** rolled back, restoring the target database to its original state, and an 9495: ** SQLite error code returned. 9496: */ 9497: int sqlite3changeset_apply( 9498: sqlite3 *db, /* Apply change to "main" db of this handle */ 9499: int nChangeset, /* Size of changeset in bytes */ 9500: void *pChangeset, /* Changeset blob */ 9501: int(*xFilter)( 9502: void *pCtx, /* Copy of sixth arg to _apply() */ 9503: const char *zTab /* Table name */ 9504: ), 9505: int(*xConflict)( 9506: void *pCtx, /* Copy of sixth arg to _apply() */ 9507: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9508: sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9509: ), 9510: void *pCtx /* First argument passed to xConflict */ 9511: ); 9512: 9513: /* 9514: ** CAPI3REF: Constants Passed To The Conflict Handler 9515: ** 9516: ** Values that may be passed as the second argument to a conflict-handler. 9517: ** 9518: ** <dl> 9519: ** <dt>SQLITE_CHANGESET_DATA<dd> 9520: ** The conflict handler is invoked with CHANGESET_DATA as the second argument 9521: ** when processing a DELETE or UPDATE change if a row with the required 9522: ** PRIMARY KEY fields is present in the database, but one or more other 9523: ** (non primary-key) fields modified by the update do not contain the 9524: ** expected "before" values. 9525: ** 9526: ** The conflicting row, in this case, is the database row with the matching 9527: ** primary key. 9528: ** 9529: ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 9530: ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 9531: ** argument when processing a DELETE or UPDATE change if a row with the 9532: ** required PRIMARY KEY fields is not present in the database. 9533: ** 9534: ** There is no conflicting row in this case. The results of invoking the 9535: ** sqlite3changeset_conflict() API are undefined. 9536: ** 9537: ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 9538: ** CHANGESET_CONFLICT is passed as the second argument to the conflict 9539: ** handler while processing an INSERT change if the operation would result 9540: ** in duplicate primary key values. 9541: ** 9542: ** The conflicting row in this case is the database row with the matching 9543: ** primary key. 9544: ** 9545: ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 9546: ** If foreign key handling is enabled, and applying a changeset leaves the 9547: ** database in a state containing foreign key violations, the conflict 9548: ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 9549: ** exactly once before the changeset is committed. If the conflict handler 9550: ** returns CHANGESET_OMIT, the changes, including those that caused the 9551: ** foreign key constraint violation, are committed. Or, if it returns 9552: ** CHANGESET_ABORT, the changeset is rolled back. 9553: ** 9554: ** No current or conflicting row information is provided. The only function 9555: ** it is possible to call on the supplied sqlite3_changeset_iter handle 9556: ** is sqlite3changeset_fk_conflicts(). 9557: ** 9558: ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 9559: ** If any other constraint violation occurs while applying a change (i.e. 9560: ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 9561: ** invoked with CHANGESET_CONSTRAINT as the second argument. 9562: ** 9563: ** There is no conflicting row in this case. The results of invoking the 9564: ** sqlite3changeset_conflict() API are undefined. 9565: ** 9566: ** </dl> 9567: */ 9568: #define SQLITE_CHANGESET_DATA 1 9569: #define SQLITE_CHANGESET_NOTFOUND 2 9570: #define SQLITE_CHANGESET_CONFLICT 3 9571: #define SQLITE_CHANGESET_CONSTRAINT 4 9572: #define SQLITE_CHANGESET_FOREIGN_KEY 5 9573: 9574: /* 9575: ** CAPI3REF: Constants Returned By The Conflict Handler 9576: ** 9577: ** A conflict handler callback must return one of the following three values. 9578: ** 9579: ** <dl> 9580: ** <dt>SQLITE_CHANGESET_OMIT<dd> 9581: ** If a conflict handler returns this value no special action is taken. The 9582: ** change that caused the conflict is not applied. The session module 9583: ** continues to the next change in the changeset. 9584: ** 9585: ** <dt>SQLITE_CHANGESET_REPLACE<dd> 9586: ** This value may only be returned if the second argument to the conflict 9587: ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 9588: ** is not the case, any changes applied so far are rolled back and the 9589: ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 9590: ** 9591: ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 9592: ** handler, then the conflicting row is either updated or deleted, depending 9593: ** on the type of change. 9594: ** 9595: ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 9596: ** handler, then the conflicting row is removed from the database and a 9597: ** second attempt to apply the change is made. If this second attempt fails, 9598: ** the original row is restored to the database before continuing. 9599: ** 9600: ** <dt>SQLITE_CHANGESET_ABORT<dd> 9601: ** If this value is returned, any changes applied so far are rolled back 9602: ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 9603: ** </dl> 9604: */ 9605: #define SQLITE_CHANGESET_OMIT 0 9606: #define SQLITE_CHANGESET_REPLACE 1 9607: #define SQLITE_CHANGESET_ABORT 2 9608: 9609: /* 9610: ** CAPI3REF: Streaming Versions of API functions. 9611: ** 9612: ** The six streaming API xxx_strm() functions serve similar purposes to the 9613: ** corresponding non-streaming API functions: 9614: ** 9615: ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9616: ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 9617: ** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply] 9618: ** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat] 9619: ** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert] 9620: ** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start] 9621: ** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset] 9622: ** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset] 9623: ** </table> 9624: ** 9625: ** Non-streaming functions that accept changesets (or patchsets) as input 9626: ** require that the entire changeset be stored in a single buffer in memory. 9627: ** Similarly, those that return a changeset or patchset do so by returning 9628: ** a pointer to a single large buffer allocated using sqlite3_malloc(). 9629: ** Normally this is convenient. However, if an application running in a 9630: ** low-memory environment is required to handle very large changesets, the 9631: ** large contiguous memory allocations required can become onerous. 9632: ** 9633: ** In order to avoid this problem, instead of a single large buffer, input 9634: ** is passed to a streaming API functions by way of a callback function that 9635: ** the sessions module invokes to incrementally request input data as it is 9636: ** required. In all cases, a pair of API function parameters such as 9637: ** 9638: ** <pre> 9639: **   int nChangeset, 9640: **   void *pChangeset, 9641: ** </pre> 9642: ** 9643: ** Is replaced by: 9644: ** 9645: ** <pre> 9646: **   int (*xInput)(void *pIn, void *pData, int *pnData), 9647: **   void *pIn, 9648: ** </pre> 9649: ** 9650: ** Each time the xInput callback is invoked by the sessions module, the first 9651: ** argument passed is a copy of the supplied pIn context pointer. The second 9652: ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 9653: ** error occurs the xInput method should copy up to (*pnData) bytes of data 9654: ** into the buffer and set (*pnData) to the actual number of bytes copied 9655: ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 9656: ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 9657: ** error code should be returned. In all cases, if an xInput callback returns 9658: ** an error, all processing is abandoned and the streaming API function 9659: ** returns a copy of the error code to the caller. 9660: ** 9661: ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 9662: ** invoked by the sessions module at any point during the lifetime of the 9663: ** iterator. If such an xInput callback returns an error, the iterator enters 9664: ** an error state, whereby all subsequent calls to iterator functions 9665: ** immediately fail with the same error code as returned by xInput. 9666: ** 9667: ** Similarly, streaming API functions that return changesets (or patchsets) 9668: ** return them in chunks by way of a callback function instead of via a 9669: ** pointer to a single large buffer. In this case, a pair of parameters such 9670: ** as: 9671: ** 9672: ** <pre> 9673: **   int *pnChangeset, 9674: **   void **ppChangeset, 9675: ** </pre> 9676: ** 9677: ** Is replaced by: 9678: ** 9679: ** <pre> 9680: **   int (*xOutput)(void *pOut, const void *pData, int nData), 9681: **   void *pOut 9682: ** </pre> 9683: ** 9684: ** The xOutput callback is invoked zero or more times to return data to 9685: ** the application. The first parameter passed to each call is a copy of the 9686: ** pOut pointer supplied by the application. The second parameter, pData, 9687: ** points to a buffer nData bytes in size containing the chunk of output 9688: ** data being returned. If the xOutput callback successfully processes the 9689: ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 9690: ** it should return some other SQLite error code. In this case processing 9691: ** is immediately abandoned and the streaming API function returns a copy 9692: ** of the xOutput error code to the application. 9693: ** 9694: ** The sessions module never invokes an xOutput callback with the third 9695: ** parameter set to a value less than or equal to zero. Other than this, 9696: ** no guarantees are made as to the size of the chunks of data returned. 9697: */ 9698: int sqlite3changeset_apply_strm( 9699: sqlite3 *db, /* Apply change to "main" db of this handle */ 9700: int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 9701: void *pIn, /* First arg for xInput */ 9702: int(*xFilter)( 9703: void *pCtx, /* Copy of sixth arg to _apply() */ 9704: const char *zTab /* Table name */ 9705: ), 9706: int(*xConflict)( 9707: void *pCtx, /* Copy of sixth arg to _apply() */ 9708: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9709: sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9710: ), 9711: void *pCtx /* First argument passed to xConflict */ 9712: ); 9713: int sqlite3changeset_concat_strm( 9714: int (*xInputA)(void *pIn, void *pData, int *pnData), 9715: void *pInA, 9716: int (*xInputB)(void *pIn, void *pData, int *pnData), 9717: void *pInB, 9718: int (*xOutput)(void *pOut, const void *pData, int nData), 9719: void *pOut 9720: ); 9721: int sqlite3changeset_invert_strm( 9722: int (*xInput)(void *pIn, void *pData, int *pnData), 9723: void *pIn, 9724: int (*xOutput)(void *pOut, const void *pData, int nData), 9725: void *pOut 9726: ); 9727: int sqlite3changeset_start_strm( 9728: sqlite3_changeset_iter **pp, 9729: int (*xInput)(void *pIn, void *pData, int *pnData), 9730: void *pIn 9731: ); 9732: int sqlite3session_changeset_strm( 9733: sqlite3_session *pSession, 9734: int (*xOutput)(void *pOut, const void *pData, int nData), 9735: void *pOut 9736: ); 9737: int sqlite3session_patchset_strm( 9738: sqlite3_session *pSession, 9739: int (*xOutput)(void *pOut, const void *pData, int nData), 9740: void *pOut 9741: ); 9742: int sqlite3changegroup_add_strm(sqlite3_changegroup*, 9743: int (*xInput)(void *pIn, void *pData, int *pnData), 9744: void *pIn 9745: ); 9746: int sqlite3changegroup_output_strm(sqlite3_changegroup*, 9747: int (*xOutput)(void *pOut, const void *pData, int nData), 9748: void *pOut 9749: ); 9750: 9751: 9752: /* 9753: ** Make sure we can call this stuff from C++. 9754: */ 9755: #ifdef __cplusplus 9756: } 9757: #endif 9758: 9759: #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 9760: 9761: /******** End of sqlite3session.h *********/ 9762: /******** Begin file fts5.h *********/ 9763: /* 9764: ** 2014 May 31 9765: ** 9766: ** The author disclaims copyright to this source code. In place of 9767: ** a legal notice, here is a blessing: 9768: ** 9769: ** May you do good and not evil. 9770: ** May you find forgiveness for yourself and forgive others. 9771: ** May you share freely, never taking more than you give. 9772: ** 9773: ****************************************************************************** 9774: ** 9775: ** Interfaces to extend FTS5. Using the interfaces defined in this file, 9776: ** FTS5 may be extended with: 9777: ** 9778: ** * custom tokenizers, and 9779: ** * custom auxiliary functions. 9780: */ 9781: 9782: 9783: #ifndef _FTS5_H 9784: #define _FTS5_H 9785: 9786: 9787: #ifdef __cplusplus 9788: extern "C" { 9789: #endif 9790: 9791: /************************************************************************* 9792: ** CUSTOM AUXILIARY FUNCTIONS 9793: ** 9794: ** Virtual table implementations may overload SQL functions by implementing 9795: ** the sqlite3_module.xFindFunction() method. 9796: */ 9797: 9798: typedef struct Fts5ExtensionApi Fts5ExtensionApi; 9799: typedef struct Fts5Context Fts5Context; 9800: typedef struct Fts5PhraseIter Fts5PhraseIter; 9801: 9802: typedef void (*fts5_extension_function)( 9803: const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 9804: Fts5Context *pFts, /* First arg to pass to pApi functions */ 9805: sqlite3_context *pCtx, /* Context for returning result/error */ 9806: int nVal, /* Number of values in apVal[] array */ 9807: sqlite3_value **apVal /* Array of trailing arguments */ 9808: ); 9809: 9810: struct Fts5PhraseIter { 9811: const unsigned char *a; 9812: const unsigned char *b; 9813: }; 9814: 9815: /* 9816: ** EXTENSION API FUNCTIONS 9817: ** 9818: ** xUserData(pFts): 9819: ** Return a copy of the context pointer the extension function was 9820: ** registered with. 9821: ** 9822: ** xColumnTotalSize(pFts, iCol, pnToken): 9823: ** If parameter iCol is less than zero, set output variable *pnToken 9824: ** to the total number of tokens in the FTS5 table. Or, if iCol is 9825: ** non-negative but less than the number of columns in the table, return 9826: ** the total number of tokens in column iCol, considering all rows in 9827: ** the FTS5 table. 9828: ** 9829: ** If parameter iCol is greater than or equal to the number of columns 9830: ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9831: ** an OOM condition or IO error), an appropriate SQLite error code is 9832: ** returned. 9833: ** 9834: ** xColumnCount(pFts): 9835: ** Return the number of columns in the table. 9836: ** 9837: ** xColumnSize(pFts, iCol, pnToken): 9838: ** If parameter iCol is less than zero, set output variable *pnToken 9839: ** to the total number of tokens in the current row. Or, if iCol is 9840: ** non-negative but less than the number of columns in the table, set 9841: ** *pnToken to the number of tokens in column iCol of the current row. 9842: ** 9843: ** If parameter iCol is greater than or equal to the number of columns 9844: ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9845: ** an OOM condition or IO error), an appropriate SQLite error code is 9846: ** returned. 9847: ** 9848: ** This function may be quite inefficient if used with an FTS5 table 9849: ** created with the "columnsize=0" option. 9850: ** 9851: ** xColumnText: 9852: ** This function attempts to retrieve the text of column iCol of the 9853: ** current document. If successful, (*pz) is set to point to a buffer 9854: ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 9855: ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 9856: ** if an error occurs, an SQLite error code is returned and the final values 9857: ** of (*pz) and (*pn) are undefined. 9858: ** 9859: ** xPhraseCount: 9860: ** Returns the number of phrases in the current query expression. 9861: ** 9862: ** xPhraseSize: 9863: ** Returns the number of tokens in phrase iPhrase of the query. Phrases 9864: ** are numbered starting from zero. 9865: ** 9866: ** xInstCount: 9867: ** Set *pnInst to the total number of occurrences of all phrases within 9868: ** the query within the current row. Return SQLITE_OK if successful, or 9869: ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 9870: ** 9871: ** This API can be quite slow if used with an FTS5 table created with the 9872: ** "detail=none" or "detail=column" option. If the FTS5 table is created 9873: ** with either "detail=none" or "detail=column" and "content=" option 9874: ** (i.e. if it is a contentless table), then this API always returns 0. 9875: ** 9876: ** xInst: 9877: ** Query for the details of phrase match iIdx within the current row. 9878: ** Phrase matches are numbered starting from zero, so the iIdx argument 9879: ** should be greater than or equal to zero and smaller than the value 9880: ** output by xInstCount(). 9881: ** 9882: ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 9883: ** to the column in which it occurs and *piOff the token offset of the 9884: ** first token of the phrase. The exception is if the table was created 9885: ** with the offsets=0 option specified. In this case *piOff is always 9886: ** set to -1. 9887: ** 9888: ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 9889: ** if an error occurs. 9890: ** 9891: ** This API can be quite slow if used with an FTS5 table created with the 9892: ** "detail=none" or "detail=column" option. 9893: ** 9894: ** xRowid: 9895: ** Returns the rowid of the current row. 9896: ** 9897: ** xTokenize: 9898: ** Tokenize text using the tokenizer belonging to the FTS5 table. 9899: ** 9900: ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 9901: ** This API function is used to query the FTS table for phrase iPhrase 9902: ** of the current query. Specifically, a query equivalent to: 9903: ** 9904: ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 9905: ** 9906: ** with $p set to a phrase equivalent to the phrase iPhrase of the 9907: ** current query is executed. Any column filter that applies to 9908: ** phrase iPhrase of the current query is included in $p. For each 9909: ** row visited, the callback function passed as the fourth argument 9910: ** is invoked. The context and API objects passed to the callback 9911: ** function may be used to access the properties of each matched row. 9912: ** Invoking Api.xUserData() returns a copy of the pointer passed as 9913: ** the third argument to pUserData. 9914: ** 9915: ** If the callback function returns any value other than SQLITE_OK, the 9916: ** query is abandoned and the xQueryPhrase function returns immediately. 9917: ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 9918: ** Otherwise, the error code is propagated upwards. 9919: ** 9920: ** If the query runs to completion without incident, SQLITE_OK is returned. 9921: ** Or, if some error occurs before the query completes or is aborted by 9922: ** the callback, an SQLite error code is returned. 9923: ** 9924: ** 9925: ** xSetAuxdata(pFts5, pAux, xDelete) 9926: ** 9927: ** Save the pointer passed as the second argument as the extension functions 9928: ** "auxiliary data". The pointer may then be retrieved by the current or any 9929: ** future invocation of the same fts5 extension function made as part of 9930: ** of the same MATCH query using the xGetAuxdata() API. 9931: ** 9932: ** Each extension function is allocated a single auxiliary data slot for 9933: ** each FTS query (MATCH expression). If the extension function is invoked 9934: ** more than once for a single FTS query, then all invocations share a 9935: ** single auxiliary data context. 9936: ** 9937: ** If there is already an auxiliary data pointer when this function is 9938: ** invoked, then it is replaced by the new pointer. If an xDelete callback 9939: ** was specified along with the original pointer, it is invoked at this 9940: ** point. 9941: ** 9942: ** The xDelete callback, if one is specified, is also invoked on the 9943: ** auxiliary data pointer after the FTS5 query has finished. 9944: ** 9945: ** If an error (e.g. an OOM condition) occurs within this function, an 9946: ** the auxiliary data is set to NULL and an error code returned. If the 9947: ** xDelete parameter was not NULL, it is invoked on the auxiliary data 9948: ** pointer before returning. 9949: ** 9950: ** 9951: ** xGetAuxdata(pFts5, bClear) 9952: ** 9953: ** Returns the current auxiliary data pointer for the fts5 extension 9954: ** function. See the xSetAuxdata() method for details. 9955: ** 9956: ** If the bClear argument is non-zero, then the auxiliary data is cleared 9957: ** (set to NULL) before this function returns. In this case the xDelete, 9958: ** if any, is not invoked. 9959: ** 9960: ** 9961: ** xRowCount(pFts5, pnRow) 9962: ** 9963: ** This function is used to retrieve the total number of rows in the table. 9964: ** In other words, the same value that would be returned by: 9965: ** 9966: ** SELECT count(*) FROM ftstable; 9967: ** 9968: ** xPhraseFirst() 9969: ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 9970: ** method, to iterate through all instances of a single query phrase within 9971: ** the current row. This is the same information as is accessible via the 9972: ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 9973: ** to use, this API may be faster under some circumstances. To iterate 9974: ** through instances of phrase iPhrase, use the following code: 9975: ** 9976: ** Fts5PhraseIter iter; 9977: ** int iCol, iOff; 9978: ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 9979: ** iCol>=0; 9980: ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 9981: ** ){ 9982: ** // An instance of phrase iPhrase at offset iOff of column iCol 9983: ** } 9984: ** 9985: ** The Fts5PhraseIter structure is defined above. Applications should not 9986: ** modify this structure directly - it should only be used as shown above 9987: ** with the xPhraseFirst() and xPhraseNext() API methods (and by 9988: ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 9989: ** 9990: ** This API can be quite slow if used with an FTS5 table created with the 9991: ** "detail=none" or "detail=column" option. If the FTS5 table is created 9992: ** with either "detail=none" or "detail=column" and "content=" option 9993: ** (i.e. if it is a contentless table), then this API always iterates 9994: ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 9995: ** 9996: ** xPhraseNext() 9997: ** See xPhraseFirst above. 9998: ** 9999: ** xPhraseFirstColumn() 10000: ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 10001: ** and xPhraseNext() APIs described above. The difference is that instead 10002: ** of iterating through all instances of a phrase in the current row, these 10003: ** APIs are used to iterate through the set of columns in the current row 10004: ** that contain one or more instances of a specified phrase. For example: 10005: ** 10006: ** Fts5PhraseIter iter; 10007: ** int iCol; 10008: ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 10009: ** iCol>=0; 10010: ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 10011: ** ){ 10012: ** // Column iCol contains at least one instance of phrase iPhrase 10013: ** } 10014: ** 10015: ** This API can be quite slow if used with an FTS5 table created with the 10016: ** "detail=none" option. If the FTS5 table is created with either 10017: ** "detail=none" "content=" option (i.e. if it is a contentless table), 10018: ** then this API always iterates through an empty set (all calls to 10019: ** xPhraseFirstColumn() set iCol to -1). 10020: ** 10021: ** The information accessed using this API and its companion 10022: ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 10023: ** (or xInst/xInstCount). The chief advantage of this API is that it is 10024: ** significantly more efficient than those alternatives when used with 10025: ** "detail=column" tables. 10026: ** 10027: ** xPhraseNextColumn() 10028: ** See xPhraseFirstColumn above. 10029: */ 10030: struct Fts5ExtensionApi { 10031: int iVersion; /* Currently always set to 3 */ 10032: 10033: void *(*xUserData)(Fts5Context*); 10034: 10035: int (*xColumnCount)(Fts5Context*); 10036: int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 10037: int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 10038: 10039: int (*xTokenize)(Fts5Context*, 10040: const char *pText, int nText, /* Text to tokenize */ 10041: void *pCtx, /* Context passed to xToken() */ 10042: int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 10043: ); 10044: 10045: int (*xPhraseCount)(Fts5Context*); 10046: int (*xPhraseSize)(Fts5Context*, int iPhrase); 10047: 10048: int (*xInstCount)(Fts5Context*, int *pnInst); 10049: int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 10050: 10051: sqlite3_int64 (*xRowid)(Fts5Context*); 10052: int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 10053: int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 10054: 10055: int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 10056: int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 10057: ); 10058: int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 10059: void *(*xGetAuxdata)(Fts5Context*, int bClear); 10060: 10061: int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 10062: void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 10063: 10064: int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 10065: void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 10066: }; 10067: 10068: /* 10069: ** CUSTOM AUXILIARY FUNCTIONS 10070: *************************************************************************/ 10071: 10072: /************************************************************************* 10073: ** CUSTOM TOKENIZERS 10074: ** 10075: ** Applications may also register custom tokenizer types. A tokenizer 10076: ** is registered by providing fts5 with a populated instance of the 10077: ** following structure. All structure methods must be defined, setting 10078: ** any member of the fts5_tokenizer struct to NULL leads to undefined 10079: ** behaviour. The structure methods are expected to function as follows: 10080: ** 10081: ** xCreate: 10082: ** This function is used to allocate and initialize a tokenizer instance. 10083: ** A tokenizer instance is required to actually tokenize text. 10084: ** 10085: ** The first argument passed to this function is a copy of the (void*) 10086: ** pointer provided by the application when the fts5_tokenizer object 10087: ** was registered with FTS5 (the third argument to xCreateTokenizer()). 10088: ** The second and third arguments are an array of nul-terminated strings 10089: ** containing the tokenizer arguments, if any, specified following the 10090: ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 10091: ** to create the FTS5 table. 10092: ** 10093: ** The final argument is an output variable. If successful, (*ppOut) 10094: ** should be set to point to the new tokenizer handle and SQLITE_OK 10095: ** returned. If an error occurs, some value other than SQLITE_OK should 10096: ** be returned. In this case, fts5 assumes that the final value of *ppOut 10097: ** is undefined. 10098: ** 10099: ** xDelete: 10100: ** This function is invoked to delete a tokenizer handle previously 10101: ** allocated using xCreate(). Fts5 guarantees that this function will 10102: ** be invoked exactly once for each successful call to xCreate(). 10103: ** 10104: ** xTokenize: 10105: ** This function is expected to tokenize the nText byte string indicated 10106: ** by argument pText. pText may or may not be nul-terminated. The first 10107: ** argument passed to this function is a pointer to an Fts5Tokenizer object 10108: ** returned by an earlier call to xCreate(). 10109: ** 10110: ** The second argument indicates the reason that FTS5 is requesting 10111: ** tokenization of the supplied text. This is always one of the following 10112: ** four values: 10113: ** 10114: ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 10115: ** or removed from the FTS table. The tokenizer is being invoked to 10116: ** determine the set of tokens to add to (or delete from) the 10117: ** FTS index. 10118: ** 10119: ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 10120: ** against the FTS index. The tokenizer is being called to tokenize 10121: ** a bareword or quoted string specified as part of the query. 10122: ** 10123: ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 10124: ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 10125: ** followed by a "*" character, indicating that the last token 10126: ** returned by the tokenizer will be treated as a token prefix. 10127: ** 10128: ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 10129: ** satisfy an fts5_api.xTokenize() request made by an auxiliary 10130: ** function. Or an fts5_api.xColumnSize() request made by the same 10131: ** on a columnsize=0 database. 10132: ** </ul> 10133: ** 10134: ** For each token in the input string, the supplied callback xToken() must 10135: ** be invoked. The first argument to it should be a copy of the pointer 10136: ** passed as the second argument to xTokenize(). The third and fourth 10137: ** arguments are a pointer to a buffer containing the token text, and the 10138: ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 10139: ** of the first byte of and first byte immediately following the text from 10140: ** which the token is derived within the input. 10141: ** 10142: ** The second argument passed to the xToken() callback ("tflags") should 10143: ** normally be set to 0. The exception is if the tokenizer supports 10144: ** synonyms. In this case see the discussion below for details. 10145: ** 10146: ** FTS5 assumes the xToken() callback is invoked for each token in the 10147: ** order that they occur within the input text. 10148: ** 10149: ** If an xToken() callback returns any value other than SQLITE_OK, then 10150: ** the tokenization should be abandoned and the xTokenize() method should 10151: ** immediately return a copy of the xToken() return value. Or, if the 10152: ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 10153: ** if an error occurs with the xTokenize() implementation itself, it 10154: ** may abandon the tokenization and return any error code other than 10155: ** SQLITE_OK or SQLITE_DONE. 10156: ** 10157: ** SYNONYM SUPPORT 10158: ** 10159: ** Custom tokenizers may also support synonyms. Consider a case in which a 10160: ** user wishes to query for a phrase such as "first place". Using the 10161: ** built-in tokenizers, the FTS5 query 'first + place' will match instances 10162: ** of "first place" within the document set, but not alternative forms 10163: ** such as "1st place". In some applications, it would be better to match 10164: ** all instances of "first place" or "1st place" regardless of which form 10165: ** the user specified in the MATCH query text. 10166: ** 10167: ** There are several ways to approach this in FTS5: 10168: ** 10169: ** <ol><li> By mapping all synonyms to a single token. In this case, the 10170: ** In the above example, this means that the tokenizer returns the 10171: ** same token for inputs "first" and "1st". Say that token is in 10172: ** fact "first", so that when the user inserts the document "I won 10173: ** 1st place" entries are added to the index for tokens "i", "won", 10174: ** "first" and "place". If the user then queries for '1st + place', 10175: ** the tokenizer substitutes "first" for "1st" and the query works 10176: ** as expected. 10177: ** 10178: ** <li> By adding multiple synonyms for a single term to the FTS index. 10179: ** In this case, when tokenizing query text, the tokenizer may 10180: ** provide multiple synonyms for a single term within the document. 10181: ** FTS5 then queries the index for each synonym individually. For 10182: ** example, faced with the query: 10183: ** 10184: ** <codeblock> 10185: ** ... MATCH 'first place'</codeblock> 10186: ** 10187: ** the tokenizer offers both "1st" and "first" as synonyms for the 10188: ** first token in the MATCH query and FTS5 effectively runs a query 10189: ** similar to: 10190: ** 10191: ** <codeblock> 10192: ** ... MATCH '(first OR 1st) place'</codeblock> 10193: ** 10194: ** except that, for the purposes of auxiliary functions, the query 10195: ** still appears to contain just two phrases - "(first OR 1st)" 10196: ** being treated as a single phrase. 10197: ** 10198: ** <li> By adding multiple synonyms for a single term to the FTS index. 10199: ** Using this method, when tokenizing document text, the tokenizer 10200: ** provides multiple synonyms for each token. So that when a 10201: ** document such as "I won first place" is tokenized, entries are 10202: ** added to the FTS index for "i", "won", "first", "1st" and 10203: ** "place". 10204: ** 10205: ** This way, even if the tokenizer does not provide synonyms 10206: ** when tokenizing query text (it should not - to do would be 10207: ** inefficient), it doesn't matter if the user queries for 10208: ** 'first + place' or '1st + place', as there are entires in the 10209: ** FTS index corresponding to both forms of the first token. 10210: ** </ol> 10211: ** 10212: ** Whether it is parsing document or query text, any call to xToken that 10213: ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 10214: ** is considered to supply a synonym for the previous token. For example, 10215: ** when parsing the document "I won first place", a tokenizer that supports 10216: ** synonyms would call xToken() 5 times, as follows: 10217: ** 10218: ** <codeblock> 10219: ** xToken(pCtx, 0, "i", 1, 0, 1); 10220: ** xToken(pCtx, 0, "won", 3, 2, 5); 10221: ** xToken(pCtx, 0, "first", 5, 6, 11); 10222: ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 10223: ** xToken(pCtx, 0, "place", 5, 12, 17); 10224: **</codeblock> 10225: ** 10226: ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 10227: ** xToken() is called. Multiple synonyms may be specified for a single token 10228: ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 10229: ** There is no limit to the number of synonyms that may be provided for a 10230: ** single token. 10231: ** 10232: ** In many cases, method (1) above is the best approach. It does not add 10233: ** extra data to the FTS index or require FTS5 to query for multiple terms, 10234: ** so it is efficient in terms of disk space and query speed. However, it 10235: ** does not support prefix queries very well. If, as suggested above, the 10236: ** token "first" is subsituted for "1st" by the tokenizer, then the query: 10237: ** 10238: ** <codeblock> 10239: ** ... MATCH '1s*'</codeblock> 10240: ** 10241: ** will not match documents that contain the token "1st" (as the tokenizer 10242: ** will probably not map "1s" to any prefix of "first"). 10243: ** 10244: ** For full prefix support, method (3) may be preferred. In this case, 10245: ** because the index contains entries for both "first" and "1st", prefix 10246: ** queries such as 'fi*' or '1s*' will match correctly. However, because 10247: ** extra entries are added to the FTS index, this method uses more space 10248: ** within the database. 10249: ** 10250: ** Method (2) offers a midpoint between (1) and (3). Using this method, 10251: ** a query such as '1s*' will match documents that contain the literal 10252: ** token "1st", but not "first" (assuming the tokenizer is not able to 10253: ** provide synonyms for prefixes). However, a non-prefix query like '1st' 10254: ** will match against "1st" and "first". This method does not require 10255: ** extra disk space, as no extra entries are added to the FTS index. 10256: ** On the other hand, it may require more CPU cycles to run MATCH queries, 10257: ** as separate queries of the FTS index are required for each synonym. 10258: ** 10259: ** When using methods (2) or (3), it is important that the tokenizer only 10260: ** provide synonyms when tokenizing document text (method (2)) or query 10261: ** text (method (3)), not both. Doing so will not cause any errors, but is 10262: ** inefficient. 10263: */ 10264: typedef struct Fts5Tokenizer Fts5Tokenizer; 10265: typedef struct fts5_tokenizer fts5_tokenizer; 10266: struct fts5_tokenizer { 10267: int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 10268: void (*xDelete)(Fts5Tokenizer*); 10269: int (*xTokenize)(Fts5Tokenizer*, 10270: void *pCtx, 10271: int flags, /* Mask of FTS5_TOKENIZE_* flags */ 10272: const char *pText, int nText, 10273: int (*xToken)( 10274: void *pCtx, /* Copy of 2nd argument to xTokenize() */ 10275: int tflags, /* Mask of FTS5_TOKEN_* flags */ 10276: const char *pToken, /* Pointer to buffer containing token */ 10277: int nToken, /* Size of token in bytes */ 10278: int iStart, /* Byte offset of token within input text */ 10279: int iEnd /* Byte offset of end of token within input text */ 10280: ) 10281: ); 10282: }; 10283: 10284: /* Flags that may be passed as the third argument to xTokenize() */ 10285: #define FTS5_TOKENIZE_QUERY 0x0001 10286: #define FTS5_TOKENIZE_PREFIX 0x0002 10287: #define FTS5_TOKENIZE_DOCUMENT 0x0004 10288: #define FTS5_TOKENIZE_AUX 0x0008 10289: 10290: /* Flags that may be passed by the tokenizer implementation back to FTS5 10291: ** as the third argument to the supplied xToken callback. */ 10292: #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 10293: 10294: /* 10295: ** END OF CUSTOM TOKENIZERS 10296: *************************************************************************/ 10297: 10298: /************************************************************************* 10299: ** FTS5 EXTENSION REGISTRATION API 10300: */ 10301: typedef struct fts5_api fts5_api; 10302: struct fts5_api { 10303: int iVersion; /* Currently always set to 2 */ 10304: 10305: /* Create a new tokenizer */ 10306: int (*xCreateTokenizer)( 10307: fts5_api *pApi, 10308: const char *zName, 10309: void *pContext, 10310: fts5_tokenizer *pTokenizer, 10311: void (*xDestroy)(void*) 10312: ); 10313: 10314: /* Find an existing tokenizer */ 10315: int (*xFindTokenizer)( 10316: fts5_api *pApi, 10317: const char *zName, 10318: void **ppContext, 10319: fts5_tokenizer *pTokenizer 10320: ); 10321: 10322: /* Create a new auxiliary function */ 10323: int (*xCreateFunction)( 10324: fts5_api *pApi, 10325: const char *zName, 10326: void *pContext, 10327: fts5_extension_function xFunction, 10328: void (*xDestroy)(void*) 10329: ); 10330: }; 10331: 10332: /* 10333: ** END OF REGISTRATION API 10334: *************************************************************************/ 10335: 10336: #ifdef __cplusplus 10337: } /* end of the 'extern "C"' block */ 10338: #endif 10339: 10340: #endif /* _FTS5_H */ 10341: 10342: /******** End of fts5.h *********/