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 suppose 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: ** Add the ability to override 'extern'
47: */
48: #ifndef SQLITE_EXTERN
49: # define SQLITE_EXTERN extern
50: #endif
51:
52: #ifndef SQLITE_API
53: # define SQLITE_API
54: #endif
55:
56:
57: /*
58: ** These no-op macros are used in front of interfaces to mark those
59: ** interfaces as either deprecated or experimental. New applications
60: ** should not use deprecated interfaces - they are support for backwards
61: ** compatibility only. Application writers should be aware that
62: ** experimental interfaces are subject to change in point releases.
63: **
64: ** These macros used to resolve to various kinds of compiler magic that
65: ** would generate warning messages when they were used. But that
66: ** compiler magic ended up generating such a flurry of bug reports
67: ** that we have taken it all out and gone back to using simple
68: ** noop macros.
69: */
70: #define SQLITE_DEPRECATED
71: #define SQLITE_EXPERIMENTAL
72:
73: /*
74: ** Ensure these symbols were not defined by some previous header file.
75: */
76: #ifdef SQLITE_VERSION
77: # undef SQLITE_VERSION
78: #endif
79: #ifdef SQLITE_VERSION_NUMBER
80: # undef SQLITE_VERSION_NUMBER
81: #endif
82:
83: /*
84: ** CAPI3REF: Compile-Time Library Version Numbers
85: **
86: ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
87: ** evaluates to a string literal that is the SQLite version in the
88: ** format "X.Y.Z" where X is the major version number (always 3 for
89: ** SQLite3) and Y is the minor version number and Z is the release number.)^
90: ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
91: ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
92: ** numbers used in [SQLITE_VERSION].)^
93: ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
94: ** be larger than the release from which it is derived. Either Y will
95: ** be held constant and Z will be incremented or else Y will be incremented
96: ** and Z will be reset to zero.
97: **
98: ** Since version 3.6.18, SQLite source code has been stored in the
99: ** <a href="http://www.fossil-scm.org/">Fossil configuration management
100: ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
101: ** a string which identifies a particular check-in of SQLite
102: ** within its configuration management system. ^The SQLITE_SOURCE_ID
103: ** string contains the date and time of the check-in (UTC) and an SHA1
104: ** hash of the entire source tree.
105: **
106: ** See also: [sqlite3_libversion()],
107: ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
108: ** [sqlite_version()] and [sqlite_source_id()].
109: */
110: #define SQLITE_VERSION "3.7.10"
111: #define SQLITE_VERSION_NUMBER 3007010
112: #define SQLITE_SOURCE_ID "2012-01-16 13:28:40 ebd01a8deffb5024a5d7494eef800d2366d97204"
113:
114: /*
115: ** CAPI3REF: Run-Time Library Version Numbers
116: ** KEYWORDS: sqlite3_version, sqlite3_sourceid
117: **
118: ** These interfaces provide the same information as the [SQLITE_VERSION],
119: ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
120: ** but are associated with the library instead of the header file. ^(Cautious
121: ** programmers might include assert() statements in their application to
122: ** verify that values returned by these interfaces match the macros in
123: ** the header, and thus insure that the application is
124: ** compiled with matching library and header files.
125: **
126: ** <blockquote><pre>
127: ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
128: ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
129: ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
130: ** </pre></blockquote>)^
131: **
132: ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
133: ** macro. ^The sqlite3_libversion() function returns a pointer to the
134: ** to the sqlite3_version[] string constant. The sqlite3_libversion()
135: ** function is provided for use in DLLs since DLL users usually do not have
136: ** direct access to string constants within the DLL. ^The
137: ** sqlite3_libversion_number() function returns an integer equal to
138: ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
139: ** a pointer to a string constant whose value is the same as the
140: ** [SQLITE_SOURCE_ID] C preprocessor macro.
141: **
142: ** See also: [sqlite_version()] and [sqlite_source_id()].
143: */
144: SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
145: SQLITE_API const char *sqlite3_libversion(void);
146: SQLITE_API const char *sqlite3_sourceid(void);
147: SQLITE_API int sqlite3_libversion_number(void);
148:
149: /*
150: ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
151: **
152: ** ^The sqlite3_compileoption_used() function returns 0 or 1
153: ** indicating whether the specified option was defined at
154: ** compile time. ^The SQLITE_ prefix may be omitted from the
155: ** option name passed to sqlite3_compileoption_used().
156: **
157: ** ^The sqlite3_compileoption_get() function allows iterating
158: ** over the list of options that were defined at compile time by
159: ** returning the N-th compile time option string. ^If N is out of range,
160: ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
161: ** prefix is omitted from any strings returned by
162: ** sqlite3_compileoption_get().
163: **
164: ** ^Support for the diagnostic functions sqlite3_compileoption_used()
165: ** and sqlite3_compileoption_get() may be omitted by specifying the
166: ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
167: **
168: ** See also: SQL functions [sqlite_compileoption_used()] and
169: ** [sqlite_compileoption_get()] and the [compile_options pragma].
170: */
171: #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
172: SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
173: SQLITE_API const char *sqlite3_compileoption_get(int N);
174: #endif
175:
176: /*
177: ** CAPI3REF: Test To See If The Library Is Threadsafe
178: **
179: ** ^The sqlite3_threadsafe() function returns zero if and only if
180: ** SQLite was compiled with mutexing code omitted due to the
181: ** [SQLITE_THREADSAFE] compile-time option being set to 0.
182: **
183: ** SQLite can be compiled with or without mutexes. When
184: ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
185: ** are enabled and SQLite is threadsafe. When the
186: ** [SQLITE_THREADSAFE] macro is 0,
187: ** the mutexes are omitted. Without the mutexes, it is not safe
188: ** to use SQLite concurrently from more than one thread.
189: **
190: ** Enabling mutexes incurs a measurable performance penalty.
191: ** So if speed is of utmost importance, it makes sense to disable
192: ** the mutexes. But for maximum safety, mutexes should be enabled.
193: ** ^The default behavior is for mutexes to be enabled.
194: **
195: ** This interface can be used by an application to make sure that the
196: ** version of SQLite that it is linking against was compiled with
197: ** the desired setting of the [SQLITE_THREADSAFE] macro.
198: **
199: ** This interface only reports on the compile-time mutex setting
200: ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
201: ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
202: ** can be fully or partially disabled using a call to [sqlite3_config()]
203: ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
204: ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the
205: ** sqlite3_threadsafe() function shows only the compile-time setting of
206: ** thread safety, not any run-time changes to that setting made by
207: ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
208: ** is unchanged by calls to sqlite3_config().)^
209: **
210: ** See the [threading mode] documentation for additional information.
211: */
212: SQLITE_API int sqlite3_threadsafe(void);
213:
214: /*
215: ** CAPI3REF: Database Connection Handle
216: ** KEYWORDS: {database connection} {database connections}
217: **
218: ** Each open SQLite database is represented by a pointer to an instance of
219: ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
220: ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
221: ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
222: ** is its destructor. There are many other interfaces (such as
223: ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
224: ** [sqlite3_busy_timeout()] to name but three) that are methods on an
225: ** sqlite3 object.
226: */
227: typedef struct sqlite3 sqlite3;
228:
229: /*
230: ** CAPI3REF: 64-Bit Integer Types
231: ** KEYWORDS: sqlite_int64 sqlite_uint64
232: **
233: ** Because there is no cross-platform way to specify 64-bit integer types
234: ** SQLite includes typedefs for 64-bit signed and unsigned integers.
235: **
236: ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
237: ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
238: ** compatibility only.
239: **
240: ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
241: ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
242: ** sqlite3_uint64 and sqlite_uint64 types can store integer values
243: ** between 0 and +18446744073709551615 inclusive.
244: */
245: #ifdef SQLITE_INT64_TYPE
246: typedef SQLITE_INT64_TYPE sqlite_int64;
247: typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
248: #elif defined(_MSC_VER) || defined(__BORLANDC__)
249: typedef __int64 sqlite_int64;
250: typedef unsigned __int64 sqlite_uint64;
251: #else
252: typedef long long int sqlite_int64;
253: typedef unsigned long long int sqlite_uint64;
254: #endif
255: typedef sqlite_int64 sqlite3_int64;
256: typedef sqlite_uint64 sqlite3_uint64;
257:
258: /*
259: ** If compiling for a processor that lacks floating point support,
260: ** substitute integer for floating-point.
261: */
262: #ifdef SQLITE_OMIT_FLOATING_POINT
263: # define double sqlite3_int64
264: #endif
265:
266: /*
267: ** CAPI3REF: Closing A Database Connection
268: **
269: ** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.
270: ** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is
271: ** successfully destroyed and all associated resources are deallocated.
272: **
273: ** Applications must [sqlite3_finalize | finalize] all [prepared statements]
274: ** and [sqlite3_blob_close | close] all [BLOB handles] associated with
275: ** the [sqlite3] object prior to attempting to close the object. ^If
276: ** sqlite3_close() is called on a [database connection] that still has
277: ** outstanding [prepared statements] or [BLOB handles], then it returns
278: ** SQLITE_BUSY.
279: **
280: ** ^If [sqlite3_close()] is invoked while a transaction is open,
281: ** the transaction is automatically rolled back.
282: **
283: ** The C parameter to [sqlite3_close(C)] must be either a NULL
284: ** pointer or an [sqlite3] object pointer obtained
285: ** from [sqlite3_open()], [sqlite3_open16()], or
286: ** [sqlite3_open_v2()], and not previously closed.
287: ** ^Calling sqlite3_close() with a NULL pointer argument is a
288: ** harmless no-op.
289: */
290: SQLITE_API int sqlite3_close(sqlite3 *);
291:
292: /*
293: ** The type for a callback function.
294: ** This is legacy and deprecated. It is included for historical
295: ** compatibility and is not documented.
296: */
297: typedef int (*sqlite3_callback)(void*,int,char**, char**);
298:
299: /*
300: ** CAPI3REF: One-Step Query Execution Interface
301: **
302: ** The sqlite3_exec() interface is a convenience wrapper around
303: ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
304: ** that allows an application to run multiple statements of SQL
305: ** without having to use a lot of C code.
306: **
307: ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
308: ** semicolon-separate SQL statements passed into its 2nd argument,
309: ** in the context of the [database connection] passed in as its 1st
310: ** argument. ^If the callback function of the 3rd argument to
311: ** sqlite3_exec() is not NULL, then it is invoked for each result row
312: ** coming out of the evaluated SQL statements. ^The 4th argument to
313: ** sqlite3_exec() is relayed through to the 1st argument of each
314: ** callback invocation. ^If the callback pointer to sqlite3_exec()
315: ** is NULL, then no callback is ever invoked and result rows are
316: ** ignored.
317: **
318: ** ^If an error occurs while evaluating the SQL statements passed into
319: ** sqlite3_exec(), then execution of the current statement stops and
320: ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
321: ** is not NULL then any error message is written into memory obtained
322: ** from [sqlite3_malloc()] and passed back through the 5th parameter.
323: ** To avoid memory leaks, the application should invoke [sqlite3_free()]
324: ** on error message strings returned through the 5th parameter of
325: ** of sqlite3_exec() after the error message string is no longer needed.
326: ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
327: ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
328: ** NULL before returning.
329: **
330: ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
331: ** routine returns SQLITE_ABORT without invoking the callback again and
332: ** without running any subsequent SQL statements.
333: **
334: ** ^The 2nd argument to the sqlite3_exec() callback function is the
335: ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
336: ** callback is an array of pointers to strings obtained as if from
337: ** [sqlite3_column_text()], one for each column. ^If an element of a
338: ** result row is NULL then the corresponding string pointer for the
339: ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
340: ** sqlite3_exec() callback is an array of pointers to strings where each
341: ** entry represents the name of corresponding result column as obtained
342: ** from [sqlite3_column_name()].
343: **
344: ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
345: ** to an empty string, or a pointer that contains only whitespace and/or
346: ** SQL comments, then no SQL statements are evaluated and the database
347: ** is not changed.
348: **
349: ** Restrictions:
350: **
351: ** <ul>
352: ** <li> The application must insure that the 1st parameter to sqlite3_exec()
353: ** is a valid and open [database connection].
354: ** <li> The application must not close [database connection] specified by
355: ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
356: ** <li> The application must not modify the SQL statement text passed into
357: ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
358: ** </ul>
359: */
360: SQLITE_API int sqlite3_exec(
361: sqlite3*, /* An open database */
362: const char *sql, /* SQL to be evaluated */
363: int (*callback)(void*,int,char**,char**), /* Callback function */
364: void *, /* 1st argument to callback */
365: char **errmsg /* Error msg written here */
366: );
367:
368: /*
369: ** CAPI3REF: Result Codes
370: ** KEYWORDS: SQLITE_OK {error code} {error codes}
371: ** KEYWORDS: {result code} {result codes}
372: **
373: ** Many SQLite functions return an integer result code from the set shown
374: ** here in order to indicate success or failure.
375: **
376: ** New error codes may be added in future versions of SQLite.
377: **
378: ** See also: [SQLITE_IOERR_READ | extended result codes],
379: ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
380: */
381: #define SQLITE_OK 0 /* Successful result */
382: /* beginning-of-error-codes */
383: #define SQLITE_ERROR 1 /* SQL error or missing database */
384: #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
385: #define SQLITE_PERM 3 /* Access permission denied */
386: #define SQLITE_ABORT 4 /* Callback routine requested an abort */
387: #define SQLITE_BUSY 5 /* The database file is locked */
388: #define SQLITE_LOCKED 6 /* A table in the database is locked */
389: #define SQLITE_NOMEM 7 /* A malloc() failed */
390: #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
391: #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
392: #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
393: #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
394: #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
395: #define SQLITE_FULL 13 /* Insertion failed because database is full */
396: #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
397: #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
398: #define SQLITE_EMPTY 16 /* Database is empty */
399: #define SQLITE_SCHEMA 17 /* The database schema changed */
400: #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
401: #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
402: #define SQLITE_MISMATCH 20 /* Data type mismatch */
403: #define SQLITE_MISUSE 21 /* Library used incorrectly */
404: #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
405: #define SQLITE_AUTH 23 /* Authorization denied */
406: #define SQLITE_FORMAT 24 /* Auxiliary database format error */
407: #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
408: #define SQLITE_NOTADB 26 /* File opened that is not a database file */
409: #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
410: #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
411: /* end-of-error-codes */
412:
413: /*
414: ** CAPI3REF: Extended Result Codes
415: ** KEYWORDS: {extended error code} {extended error codes}
416: ** KEYWORDS: {extended result code} {extended result codes}
417: **
418: ** In its default configuration, SQLite API routines return one of 26 integer
419: ** [SQLITE_OK | result codes]. However, experience has shown that many of
420: ** these result codes are too coarse-grained. They do not provide as
421: ** much information about problems as programmers might like. In an effort to
422: ** address this, newer versions of SQLite (version 3.3.8 and later) include
423: ** support for additional result codes that provide more detailed information
424: ** about errors. The extended result codes are enabled or disabled
425: ** on a per database connection basis using the
426: ** [sqlite3_extended_result_codes()] API.
427: **
428: ** Some of the available extended result codes are listed here.
429: ** One may expect the number of extended result codes will be expand
430: ** over time. Software that uses extended result codes should expect
431: ** to see new result codes in future releases of SQLite.
432: **
433: ** The SQLITE_OK result code will never be extended. It will always
434: ** be exactly zero.
435: */
436: #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
437: #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
438: #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
439: #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
440: #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
441: #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
442: #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
443: #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
444: #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
445: #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
446: #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
447: #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
448: #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
449: #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
450: #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
451: #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
452: #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
453: #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
454: #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
455: #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
456: #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
457: #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
458: #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
459: #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
460: #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
461: #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
462: #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
463: #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
464:
465: /*
466: ** CAPI3REF: Flags For File Open Operations
467: **
468: ** These bit values are intended for use in the
469: ** 3rd parameter to the [sqlite3_open_v2()] interface and
470: ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
471: */
472: #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
473: #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
474: #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
475: #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
476: #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
477: #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
478: #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
479: #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
480: #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
481: #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
482: #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
483: #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
484: #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
485: #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
486: #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
487: #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
488: #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
489: #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
490: #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
491:
492: /* Reserved: 0x00F00000 */
493:
494: /*
495: ** CAPI3REF: Device Characteristics
496: **
497: ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
498: ** object returns an integer which is a vector of the these
499: ** bit values expressing I/O characteristics of the mass storage
500: ** device that holds the file that the [sqlite3_io_methods]
501: ** refers to.
502: **
503: ** The SQLITE_IOCAP_ATOMIC property means that all writes of
504: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
505: ** mean that writes of blocks that are nnn bytes in size and
506: ** are aligned to an address which is an integer multiple of
507: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
508: ** that when data is appended to a file, the data is appended
509: ** first then the size of the file is extended, never the other
510: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
511: ** information is written to disk in the same order as calls
512: ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
513: ** after reboot following a crash or power loss, the only bytes in a
514: ** file that were written at the application level might have changed
515: ** and that adjacent bytes, even bytes within the same sector are
516: ** guaranteed to be unchanged.
517: */
518: #define SQLITE_IOCAP_ATOMIC 0x00000001
519: #define SQLITE_IOCAP_ATOMIC512 0x00000002
520: #define SQLITE_IOCAP_ATOMIC1K 0x00000004
521: #define SQLITE_IOCAP_ATOMIC2K 0x00000008
522: #define SQLITE_IOCAP_ATOMIC4K 0x00000010
523: #define SQLITE_IOCAP_ATOMIC8K 0x00000020
524: #define SQLITE_IOCAP_ATOMIC16K 0x00000040
525: #define SQLITE_IOCAP_ATOMIC32K 0x00000080
526: #define SQLITE_IOCAP_ATOMIC64K 0x00000100
527: #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
528: #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
529: #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
530: #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
531:
532: /*
533: ** CAPI3REF: File Locking Levels
534: **
535: ** SQLite uses one of these integer values as the second
536: ** argument to calls it makes to the xLock() and xUnlock() methods
537: ** of an [sqlite3_io_methods] object.
538: */
539: #define SQLITE_LOCK_NONE 0
540: #define SQLITE_LOCK_SHARED 1
541: #define SQLITE_LOCK_RESERVED 2
542: #define SQLITE_LOCK_PENDING 3
543: #define SQLITE_LOCK_EXCLUSIVE 4
544:
545: /*
546: ** CAPI3REF: Synchronization Type Flags
547: **
548: ** When SQLite invokes the xSync() method of an
549: ** [sqlite3_io_methods] object it uses a combination of
550: ** these integer values as the second argument.
551: **
552: ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
553: ** sync operation only needs to flush data to mass storage. Inode
554: ** information need not be flushed. If the lower four bits of the flag
555: ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
556: ** If the lower four bits equal SQLITE_SYNC_FULL, that means
557: ** to use Mac OS X style fullsync instead of fsync().
558: **
559: ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
560: ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
561: ** settings. The [synchronous pragma] determines when calls to the
562: ** xSync VFS method occur and applies uniformly across all platforms.
563: ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
564: ** energetic or rigorous or forceful the sync operations are and
565: ** only make a difference on Mac OSX for the default SQLite code.
566: ** (Third-party VFS implementations might also make the distinction
567: ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
568: ** operating systems natively supported by SQLite, only Mac OSX
569: ** cares about the difference.)
570: */
571: #define SQLITE_SYNC_NORMAL 0x00002
572: #define SQLITE_SYNC_FULL 0x00003
573: #define SQLITE_SYNC_DATAONLY 0x00010
574:
575: /*
576: ** CAPI3REF: OS Interface Open File Handle
577: **
578: ** An [sqlite3_file] object represents an open file in the
579: ** [sqlite3_vfs | OS interface layer]. Individual OS interface
580: ** implementations will
581: ** want to subclass this object by appending additional fields
582: ** for their own use. The pMethods entry is a pointer to an
583: ** [sqlite3_io_methods] object that defines methods for performing
584: ** I/O operations on the open file.
585: */
586: typedef struct sqlite3_file sqlite3_file;
587: struct sqlite3_file {
588: const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
589: };
590:
591: /*
592: ** CAPI3REF: OS Interface File Virtual Methods Object
593: **
594: ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
595: ** [sqlite3_file] object (or, more commonly, a subclass of the
596: ** [sqlite3_file] object) with a pointer to an instance of this object.
597: ** This object defines the methods used to perform various operations
598: ** against the open file represented by the [sqlite3_file] object.
599: **
600: ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
601: ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
602: ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
603: ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
604: ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
605: ** to NULL.
606: **
607: ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
608: ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
609: ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
610: ** flag may be ORed in to indicate that only the data of the file
611: ** and not its inode needs to be synced.
612: **
613: ** The integer values to xLock() and xUnlock() are one of
614: ** <ul>
615: ** <li> [SQLITE_LOCK_NONE],
616: ** <li> [SQLITE_LOCK_SHARED],
617: ** <li> [SQLITE_LOCK_RESERVED],
618: ** <li> [SQLITE_LOCK_PENDING], or
619: ** <li> [SQLITE_LOCK_EXCLUSIVE].
620: ** </ul>
621: ** xLock() increases the lock. xUnlock() decreases the lock.
622: ** The xCheckReservedLock() method checks whether any database connection,
623: ** either in this process or in some other process, is holding a RESERVED,
624: ** PENDING, or EXCLUSIVE lock on the file. It returns true
625: ** if such a lock exists and false otherwise.
626: **
627: ** The xFileControl() method is a generic interface that allows custom
628: ** VFS implementations to directly control an open file using the
629: ** [sqlite3_file_control()] interface. The second "op" argument is an
630: ** integer opcode. The third argument is a generic pointer intended to
631: ** point to a structure that may contain arguments or space in which to
632: ** write return values. Potential uses for xFileControl() might be
633: ** functions to enable blocking locks with timeouts, to change the
634: ** locking strategy (for example to use dot-file locks), to inquire
635: ** about the status of a lock, or to break stale locks. The SQLite
636: ** core reserves all opcodes less than 100 for its own use.
637: ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
638: ** Applications that define a custom xFileControl method should use opcodes
639: ** greater than 100 to avoid conflicts. VFS implementations should
640: ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
641: ** recognize.
642: **
643: ** The xSectorSize() method returns the sector size of the
644: ** device that underlies the file. The sector size is the
645: ** minimum write that can be performed without disturbing
646: ** other bytes in the file. The xDeviceCharacteristics()
647: ** method returns a bit vector describing behaviors of the
648: ** underlying device:
649: **
650: ** <ul>
651: ** <li> [SQLITE_IOCAP_ATOMIC]
652: ** <li> [SQLITE_IOCAP_ATOMIC512]
653: ** <li> [SQLITE_IOCAP_ATOMIC1K]
654: ** <li> [SQLITE_IOCAP_ATOMIC2K]
655: ** <li> [SQLITE_IOCAP_ATOMIC4K]
656: ** <li> [SQLITE_IOCAP_ATOMIC8K]
657: ** <li> [SQLITE_IOCAP_ATOMIC16K]
658: ** <li> [SQLITE_IOCAP_ATOMIC32K]
659: ** <li> [SQLITE_IOCAP_ATOMIC64K]
660: ** <li> [SQLITE_IOCAP_SAFE_APPEND]
661: ** <li> [SQLITE_IOCAP_SEQUENTIAL]
662: ** </ul>
663: **
664: ** The SQLITE_IOCAP_ATOMIC property means that all writes of
665: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
666: ** mean that writes of blocks that are nnn bytes in size and
667: ** are aligned to an address which is an integer multiple of
668: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
669: ** that when data is appended to a file, the data is appended
670: ** first then the size of the file is extended, never the other
671: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
672: ** information is written to disk in the same order as calls
673: ** to xWrite().
674: **
675: ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
676: ** in the unread portions of the buffer with zeros. A VFS that
677: ** fails to zero-fill short reads might seem to work. However,
678: ** failure to zero-fill short reads will eventually lead to
679: ** database corruption.
680: */
681: typedef struct sqlite3_io_methods sqlite3_io_methods;
682: struct sqlite3_io_methods {
683: int iVersion;
684: int (*xClose)(sqlite3_file*);
685: int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
686: int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
687: int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
688: int (*xSync)(sqlite3_file*, int flags);
689: int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
690: int (*xLock)(sqlite3_file*, int);
691: int (*xUnlock)(sqlite3_file*, int);
692: int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
693: int (*xFileControl)(sqlite3_file*, int op, void *pArg);
694: int (*xSectorSize)(sqlite3_file*);
695: int (*xDeviceCharacteristics)(sqlite3_file*);
696: /* Methods above are valid for version 1 */
697: int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
698: int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
699: void (*xShmBarrier)(sqlite3_file*);
700: int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
701: /* Methods above are valid for version 2 */
702: /* Additional methods may be added in future releases */
703: };
704:
705: /*
706: ** CAPI3REF: Standard File Control Opcodes
707: **
708: ** These integer constants are opcodes for the xFileControl method
709: ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
710: ** interface.
711: **
712: ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
713: ** opcode causes the xFileControl method to write the current state of
714: ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
715: ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
716: ** into an integer that the pArg argument points to. This capability
717: ** is used during testing and only needs to be supported when SQLITE_TEST
718: ** is defined.
719: **
720: ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
721: ** layer a hint of how large the database file will grow to be during the
722: ** current transaction. This hint is not guaranteed to be accurate but it
723: ** is often close. The underlying VFS might choose to preallocate database
724: ** file space based on this hint in order to help writes to the database
725: ** file run faster.
726: **
727: ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
728: ** extends and truncates the database file in chunks of a size specified
729: ** by the user. The fourth argument to [sqlite3_file_control()] should
730: ** point to an integer (type int) containing the new chunk-size to use
731: ** for the nominated database. Allocating database file space in large
732: ** chunks (say 1MB at a time), may reduce file-system fragmentation and
733: ** improve performance on some systems.
734: **
735: ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
736: ** to the [sqlite3_file] object associated with a particular database
737: ** connection. See the [sqlite3_file_control()] documentation for
738: ** additional information.
739: **
740: ** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
741: ** SQLite and sent to all VFSes in place of a call to the xSync method
742: ** when the database connection has [PRAGMA synchronous] set to OFF.)^
743: ** Some specialized VFSes need this signal in order to operate correctly
744: ** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most
745: ** VFSes do not need this signal and should silently ignore this opcode.
746: ** Applications should not call [sqlite3_file_control()] with this
747: ** opcode as doing so may disrupt the operation of the specialized VFSes
748: ** that do require it.
749: **
750: ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
751: ** retry counts and intervals for certain disk I/O operations for the
752: ** windows [VFS] in order to provide robustness in the presence of
753: ** anti-virus programs. By default, the windows VFS will retry file read,
754: ** file write, and file delete operations up to 10 times, with a delay
755: ** of 25 milliseconds before the first retry and with the delay increasing
756: ** by an additional 25 milliseconds with each subsequent retry. This
757: ** opcode allows these two values (10 retries and 25 milliseconds of delay)
758: ** to be adjusted. The values are changed for all database connections
759: ** within the same process. The argument is a pointer to an array of two
760: ** integers where the first integer i the new retry count and the second
761: ** integer is the delay. If either integer is negative, then the setting
762: ** is not changed but instead the prior value of that setting is written
763: ** into the array entry, allowing the current retry settings to be
764: ** interrogated. The zDbName parameter is ignored.
765: **
766: ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
767: ** persistent [WAL | Write AHead Log] setting. By default, the auxiliary
768: ** write ahead log and shared memory files used for transaction control
769: ** are automatically deleted when the latest connection to the database
770: ** closes. Setting persistent WAL mode causes those files to persist after
771: ** close. Persisting the files is useful when other processes that do not
772: ** have write permission on the directory containing the database file want
773: ** to read the database file, as the WAL and shared memory files must exist
774: ** in order for the database to be readable. The fourth parameter to
775: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
776: ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
777: ** WAL mode. If the integer is -1, then it is overwritten with the current
778: ** WAL persistence setting.
779: **
780: ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
781: ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
782: ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
783: ** xDeviceCharacteristics methods. The fourth parameter to
784: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
785: ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
786: ** mode. If the integer is -1, then it is overwritten with the current
787: ** zero-damage mode setting.
788: **
789: ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
790: ** a write transaction to indicate that, unless it is rolled back for some
791: ** reason, the entire database file will be overwritten by the current
792: ** transaction. This is used by VACUUM operations.
793: **
794: ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
795: ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
796: ** final bottom-level VFS are written into memory obtained from
797: ** [sqlite3_malloc()] and the result is stored in the char* variable
798: ** that the fourth parameter of [sqlite3_file_control()] points to.
799: ** The caller is responsible for freeing the memory when done. As with
800: ** all file-control actions, there is no guarantee that this will actually
801: ** do anything. Callers should initialize the char* variable to a NULL
802: ** pointer in case this file-control is not implemented. This file-control
803: ** is intended for diagnostic use only.
804: */
805: #define SQLITE_FCNTL_LOCKSTATE 1
806: #define SQLITE_GET_LOCKPROXYFILE 2
807: #define SQLITE_SET_LOCKPROXYFILE 3
808: #define SQLITE_LAST_ERRNO 4
809: #define SQLITE_FCNTL_SIZE_HINT 5
810: #define SQLITE_FCNTL_CHUNK_SIZE 6
811: #define SQLITE_FCNTL_FILE_POINTER 7
812: #define SQLITE_FCNTL_SYNC_OMITTED 8
813: #define SQLITE_FCNTL_WIN32_AV_RETRY 9
814: #define SQLITE_FCNTL_PERSIST_WAL 10
815: #define SQLITE_FCNTL_OVERWRITE 11
816: #define SQLITE_FCNTL_VFSNAME 12
817: #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
818:
819: /*
820: ** CAPI3REF: Mutex Handle
821: **
822: ** The mutex module within SQLite defines [sqlite3_mutex] to be an
823: ** abstract type for a mutex object. The SQLite core never looks
824: ** at the internal representation of an [sqlite3_mutex]. It only
825: ** deals with pointers to the [sqlite3_mutex] object.
826: **
827: ** Mutexes are created using [sqlite3_mutex_alloc()].
828: */
829: typedef struct sqlite3_mutex sqlite3_mutex;
830:
831: /*
832: ** CAPI3REF: OS Interface Object
833: **
834: ** An instance of the sqlite3_vfs object defines the interface between
835: ** the SQLite core and the underlying operating system. The "vfs"
836: ** in the name of the object stands for "virtual file system". See
837: ** the [VFS | VFS documentation] for further information.
838: **
839: ** The value of the iVersion field is initially 1 but may be larger in
840: ** future versions of SQLite. Additional fields may be appended to this
841: ** object when the iVersion value is increased. Note that the structure
842: ** of the sqlite3_vfs object changes in the transaction between
843: ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
844: ** modified.
845: **
846: ** The szOsFile field is the size of the subclassed [sqlite3_file]
847: ** structure used by this VFS. mxPathname is the maximum length of
848: ** a pathname in this VFS.
849: **
850: ** Registered sqlite3_vfs objects are kept on a linked list formed by
851: ** the pNext pointer. The [sqlite3_vfs_register()]
852: ** and [sqlite3_vfs_unregister()] interfaces manage this list
853: ** in a thread-safe way. The [sqlite3_vfs_find()] interface
854: ** searches the list. Neither the application code nor the VFS
855: ** implementation should use the pNext pointer.
856: **
857: ** The pNext field is the only field in the sqlite3_vfs
858: ** structure that SQLite will ever modify. SQLite will only access
859: ** or modify this field while holding a particular static mutex.
860: ** The application should never modify anything within the sqlite3_vfs
861: ** object once the object has been registered.
862: **
863: ** The zName field holds the name of the VFS module. The name must
864: ** be unique across all VFS modules.
865: **
866: ** [[sqlite3_vfs.xOpen]]
867: ** ^SQLite guarantees that the zFilename parameter to xOpen
868: ** is either a NULL pointer or string obtained
869: ** from xFullPathname() with an optional suffix added.
870: ** ^If a suffix is added to the zFilename parameter, it will
871: ** consist of a single "-" character followed by no more than
872: ** 11 alphanumeric and/or "-" characters.
873: ** ^SQLite further guarantees that
874: ** the string will be valid and unchanged until xClose() is
875: ** called. Because of the previous sentence,
876: ** the [sqlite3_file] can safely store a pointer to the
877: ** filename if it needs to remember the filename for some reason.
878: ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
879: ** must invent its own temporary name for the file. ^Whenever the
880: ** xFilename parameter is NULL it will also be the case that the
881: ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
882: **
883: ** The flags argument to xOpen() includes all bits set in
884: ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
885: ** or [sqlite3_open16()] is used, then flags includes at least
886: ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
887: ** If xOpen() opens a file read-only then it sets *pOutFlags to
888: ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
889: **
890: ** ^(SQLite will also add one of the following flags to the xOpen()
891: ** call, depending on the object being opened:
892: **
893: ** <ul>
894: ** <li> [SQLITE_OPEN_MAIN_DB]
895: ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
896: ** <li> [SQLITE_OPEN_TEMP_DB]
897: ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
898: ** <li> [SQLITE_OPEN_TRANSIENT_DB]
899: ** <li> [SQLITE_OPEN_SUBJOURNAL]
900: ** <li> [SQLITE_OPEN_MASTER_JOURNAL]
901: ** <li> [SQLITE_OPEN_WAL]
902: ** </ul>)^
903: **
904: ** The file I/O implementation can use the object type flags to
905: ** change the way it deals with files. For example, an application
906: ** that does not care about crash recovery or rollback might make
907: ** the open of a journal file a no-op. Writes to this journal would
908: ** also be no-ops, and any attempt to read the journal would return
909: ** SQLITE_IOERR. Or the implementation might recognize that a database
910: ** file will be doing page-aligned sector reads and writes in a random
911: ** order and set up its I/O subsystem accordingly.
912: **
913: ** SQLite might also add one of the following flags to the xOpen method:
914: **
915: ** <ul>
916: ** <li> [SQLITE_OPEN_DELETEONCLOSE]
917: ** <li> [SQLITE_OPEN_EXCLUSIVE]
918: ** </ul>
919: **
920: ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
921: ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
922: ** will be set for TEMP databases and their journals, transient
923: ** databases, and subjournals.
924: **
925: ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
926: ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
927: ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
928: ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
929: ** SQLITE_OPEN_CREATE, is used to indicate that file should always
930: ** be created, and that it is an error if it already exists.
931: ** It is <i>not</i> used to indicate the file should be opened
932: ** for exclusive access.
933: **
934: ** ^At least szOsFile bytes of memory are allocated by SQLite
935: ** to hold the [sqlite3_file] structure passed as the third
936: ** argument to xOpen. The xOpen method does not have to
937: ** allocate the structure; it should just fill it in. Note that
938: ** the xOpen method must set the sqlite3_file.pMethods to either
939: ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
940: ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
941: ** element will be valid after xOpen returns regardless of the success
942: ** or failure of the xOpen call.
943: **
944: ** [[sqlite3_vfs.xAccess]]
945: ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
946: ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
947: ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
948: ** to test whether a file is at least readable. The file can be a
949: ** directory.
950: **
951: ** ^SQLite will always allocate at least mxPathname+1 bytes for the
952: ** output buffer xFullPathname. The exact size of the output buffer
953: ** is also passed as a parameter to both methods. If the output buffer
954: ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
955: ** handled as a fatal error by SQLite, vfs implementations should endeavor
956: ** to prevent this by setting mxPathname to a sufficiently large value.
957: **
958: ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
959: ** interfaces are not strictly a part of the filesystem, but they are
960: ** included in the VFS structure for completeness.
961: ** The xRandomness() function attempts to return nBytes bytes
962: ** of good-quality randomness into zOut. The return value is
963: ** the actual number of bytes of randomness obtained.
964: ** The xSleep() method causes the calling thread to sleep for at
965: ** least the number of microseconds given. ^The xCurrentTime()
966: ** method returns a Julian Day Number for the current date and time as
967: ** a floating point value.
968: ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
969: ** Day Number multiplied by 86400000 (the number of milliseconds in
970: ** a 24-hour day).
971: ** ^SQLite will use the xCurrentTimeInt64() method to get the current
972: ** date and time if that method is available (if iVersion is 2 or
973: ** greater and the function pointer is not NULL) and will fall back
974: ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
975: **
976: ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
977: ** are not used by the SQLite core. These optional interfaces are provided
978: ** by some VFSes to facilitate testing of the VFS code. By overriding
979: ** system calls with functions under its control, a test program can
980: ** simulate faults and error conditions that would otherwise be difficult
981: ** or impossible to induce. The set of system calls that can be overridden
982: ** varies from one VFS to another, and from one version of the same VFS to the
983: ** next. Applications that use these interfaces must be prepared for any
984: ** or all of these interfaces to be NULL or for their behavior to change
985: ** from one release to the next. Applications must not attempt to access
986: ** any of these methods if the iVersion of the VFS is less than 3.
987: */
988: typedef struct sqlite3_vfs sqlite3_vfs;
989: typedef void (*sqlite3_syscall_ptr)(void);
990: struct sqlite3_vfs {
991: int iVersion; /* Structure version number (currently 3) */
992: int szOsFile; /* Size of subclassed sqlite3_file */
993: int mxPathname; /* Maximum file pathname length */
994: sqlite3_vfs *pNext; /* Next registered VFS */
995: const char *zName; /* Name of this virtual file system */
996: void *pAppData; /* Pointer to application-specific data */
997: int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
998: int flags, int *pOutFlags);
999: int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1000: int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1001: int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1002: void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1003: void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1004: void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1005: void (*xDlClose)(sqlite3_vfs*, void*);
1006: int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1007: int (*xSleep)(sqlite3_vfs*, int microseconds);
1008: int (*xCurrentTime)(sqlite3_vfs*, double*);
1009: int (*xGetLastError)(sqlite3_vfs*, int, char *);
1010: /*
1011: ** The methods above are in version 1 of the sqlite_vfs object
1012: ** definition. Those that follow are added in version 2 or later
1013: */
1014: int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1015: /*
1016: ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1017: ** Those below are for version 3 and greater.
1018: */
1019: int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1020: sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1021: const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1022: /*
1023: ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1024: ** New fields may be appended in figure versions. The iVersion
1025: ** value will increment whenever this happens.
1026: */
1027: };
1028:
1029: /*
1030: ** CAPI3REF: Flags for the xAccess VFS method
1031: **
1032: ** These integer constants can be used as the third parameter to
1033: ** the xAccess method of an [sqlite3_vfs] object. They determine
1034: ** what kind of permissions the xAccess method is looking for.
1035: ** With SQLITE_ACCESS_EXISTS, the xAccess method
1036: ** simply checks whether the file exists.
1037: ** With SQLITE_ACCESS_READWRITE, the xAccess method
1038: ** checks whether the named directory is both readable and writable
1039: ** (in other words, if files can be added, removed, and renamed within
1040: ** the directory).
1041: ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1042: ** [temp_store_directory pragma], though this could change in a future
1043: ** release of SQLite.
1044: ** With SQLITE_ACCESS_READ, the xAccess method
1045: ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1046: ** currently unused, though it might be used in a future release of
1047: ** SQLite.
1048: */
1049: #define SQLITE_ACCESS_EXISTS 0
1050: #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1051: #define SQLITE_ACCESS_READ 2 /* Unused */
1052:
1053: /*
1054: ** CAPI3REF: Flags for the xShmLock VFS method
1055: **
1056: ** These integer constants define the various locking operations
1057: ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1058: ** following are the only legal combinations of flags to the
1059: ** xShmLock method:
1060: **
1061: ** <ul>
1062: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1063: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1064: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1065: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1066: ** </ul>
1067: **
1068: ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1069: ** was given no the corresponding lock.
1070: **
1071: ** The xShmLock method can transition between unlocked and SHARED or
1072: ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1073: ** and EXCLUSIVE.
1074: */
1075: #define SQLITE_SHM_UNLOCK 1
1076: #define SQLITE_SHM_LOCK 2
1077: #define SQLITE_SHM_SHARED 4
1078: #define SQLITE_SHM_EXCLUSIVE 8
1079:
1080: /*
1081: ** CAPI3REF: Maximum xShmLock index
1082: **
1083: ** The xShmLock method on [sqlite3_io_methods] may use values
1084: ** between 0 and this upper bound as its "offset" argument.
1085: ** The SQLite core will never attempt to acquire or release a
1086: ** lock outside of this range
1087: */
1088: #define SQLITE_SHM_NLOCK 8
1089:
1090:
1091: /*
1092: ** CAPI3REF: Initialize The SQLite Library
1093: **
1094: ** ^The sqlite3_initialize() routine initializes the
1095: ** SQLite library. ^The sqlite3_shutdown() routine
1096: ** deallocates any resources that were allocated by sqlite3_initialize().
1097: ** These routines are designed to aid in process initialization and
1098: ** shutdown on embedded systems. Workstation applications using
1099: ** SQLite normally do not need to invoke either of these routines.
1100: **
1101: ** A call to sqlite3_initialize() is an "effective" call if it is
1102: ** the first time sqlite3_initialize() is invoked during the lifetime of
1103: ** the process, or if it is the first time sqlite3_initialize() is invoked
1104: ** following a call to sqlite3_shutdown(). ^(Only an effective call
1105: ** of sqlite3_initialize() does any initialization. All other calls
1106: ** are harmless no-ops.)^
1107: **
1108: ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1109: ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1110: ** an effective call to sqlite3_shutdown() does any deinitialization.
1111: ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1112: **
1113: ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1114: ** is not. The sqlite3_shutdown() interface must only be called from a
1115: ** single thread. All open [database connections] must be closed and all
1116: ** other SQLite resources must be deallocated prior to invoking
1117: ** sqlite3_shutdown().
1118: **
1119: ** Among other things, ^sqlite3_initialize() will invoke
1120: ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1121: ** will invoke sqlite3_os_end().
1122: **
1123: ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1124: ** ^If for some reason, sqlite3_initialize() is unable to initialize
1125: ** the library (perhaps it is unable to allocate a needed resource such
1126: ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1127: **
1128: ** ^The sqlite3_initialize() routine is called internally by many other
1129: ** SQLite interfaces so that an application usually does not need to
1130: ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1131: ** calls sqlite3_initialize() so the SQLite library will be automatically
1132: ** initialized when [sqlite3_open()] is called if it has not be initialized
1133: ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1134: ** compile-time option, then the automatic calls to sqlite3_initialize()
1135: ** are omitted and the application must call sqlite3_initialize() directly
1136: ** prior to using any other SQLite interface. For maximum portability,
1137: ** it is recommended that applications always invoke sqlite3_initialize()
1138: ** directly prior to using any other SQLite interface. Future releases
1139: ** of SQLite may require this. In other words, the behavior exhibited
1140: ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1141: ** default behavior in some future release of SQLite.
1142: **
1143: ** The sqlite3_os_init() routine does operating-system specific
1144: ** initialization of the SQLite library. The sqlite3_os_end()
1145: ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1146: ** performed by these routines include allocation or deallocation
1147: ** of static resources, initialization of global variables,
1148: ** setting up a default [sqlite3_vfs] module, or setting up
1149: ** a default configuration using [sqlite3_config()].
1150: **
1151: ** The application should never invoke either sqlite3_os_init()
1152: ** or sqlite3_os_end() directly. The application should only invoke
1153: ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1154: ** interface is called automatically by sqlite3_initialize() and
1155: ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1156: ** implementations for sqlite3_os_init() and sqlite3_os_end()
1157: ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1158: ** When [custom builds | built for other platforms]
1159: ** (using the [SQLITE_OS_OTHER=1] compile-time
1160: ** option) the application must supply a suitable implementation for
1161: ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1162: ** implementation of sqlite3_os_init() or sqlite3_os_end()
1163: ** must return [SQLITE_OK] on success and some other [error code] upon
1164: ** failure.
1165: */
1166: SQLITE_API int sqlite3_initialize(void);
1167: SQLITE_API int sqlite3_shutdown(void);
1168: SQLITE_API int sqlite3_os_init(void);
1169: SQLITE_API int sqlite3_os_end(void);
1170:
1171: /*
1172: ** CAPI3REF: Configuring The SQLite Library
1173: **
1174: ** The sqlite3_config() interface is used to make global configuration
1175: ** changes to SQLite in order to tune SQLite to the specific needs of
1176: ** the application. The default configuration is recommended for most
1177: ** applications and so this routine is usually not necessary. It is
1178: ** provided to support rare applications with unusual needs.
1179: **
1180: ** The sqlite3_config() interface is not threadsafe. The application
1181: ** must insure that no other SQLite interfaces are invoked by other
1182: ** threads while sqlite3_config() is running. Furthermore, sqlite3_config()
1183: ** may only be invoked prior to library initialization using
1184: ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1185: ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1186: ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1187: ** Note, however, that ^sqlite3_config() can be called as part of the
1188: ** implementation of an application-defined [sqlite3_os_init()].
1189: **
1190: ** The first argument to sqlite3_config() is an integer
1191: ** [configuration option] that determines
1192: ** what property of SQLite is to be configured. Subsequent arguments
1193: ** vary depending on the [configuration option]
1194: ** in the first argument.
1195: **
1196: ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1197: ** ^If the option is unknown or SQLite is unable to set the option
1198: ** then this routine returns a non-zero [error code].
1199: */
1200: SQLITE_API int sqlite3_config(int, ...);
1201:
1202: /*
1203: ** CAPI3REF: Configure database connections
1204: **
1205: ** The sqlite3_db_config() interface is used to make configuration
1206: ** changes to a [database connection]. The interface is similar to
1207: ** [sqlite3_config()] except that the changes apply to a single
1208: ** [database connection] (specified in the first argument).
1209: **
1210: ** The second argument to sqlite3_db_config(D,V,...) is the
1211: ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1212: ** that indicates what aspect of the [database connection] is being configured.
1213: ** Subsequent arguments vary depending on the configuration verb.
1214: **
1215: ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1216: ** the call is considered successful.
1217: */
1218: SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1219:
1220: /*
1221: ** CAPI3REF: Memory Allocation Routines
1222: **
1223: ** An instance of this object defines the interface between SQLite
1224: ** and low-level memory allocation routines.
1225: **
1226: ** This object is used in only one place in the SQLite interface.
1227: ** A pointer to an instance of this object is the argument to
1228: ** [sqlite3_config()] when the configuration option is
1229: ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1230: ** By creating an instance of this object
1231: ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1232: ** during configuration, an application can specify an alternative
1233: ** memory allocation subsystem for SQLite to use for all of its
1234: ** dynamic memory needs.
1235: **
1236: ** Note that SQLite comes with several [built-in memory allocators]
1237: ** that are perfectly adequate for the overwhelming majority of applications
1238: ** and that this object is only useful to a tiny minority of applications
1239: ** with specialized memory allocation requirements. This object is
1240: ** also used during testing of SQLite in order to specify an alternative
1241: ** memory allocator that simulates memory out-of-memory conditions in
1242: ** order to verify that SQLite recovers gracefully from such
1243: ** conditions.
1244: **
1245: ** The xMalloc, xRealloc, and xFree methods must work like the
1246: ** malloc(), realloc() and free() functions from the standard C library.
1247: ** ^SQLite guarantees that the second argument to
1248: ** xRealloc is always a value returned by a prior call to xRoundup.
1249: **
1250: ** xSize should return the allocated size of a memory allocation
1251: ** previously obtained from xMalloc or xRealloc. The allocated size
1252: ** is always at least as big as the requested size but may be larger.
1253: **
1254: ** The xRoundup method returns what would be the allocated size of
1255: ** a memory allocation given a particular requested size. Most memory
1256: ** allocators round up memory allocations at least to the next multiple
1257: ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1258: ** Every memory allocation request coming in through [sqlite3_malloc()]
1259: ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1260: ** that causes the corresponding memory allocation to fail.
1261: **
1262: ** The xInit method initializes the memory allocator. (For example,
1263: ** it might allocate any require mutexes or initialize internal data
1264: ** structures. The xShutdown method is invoked (indirectly) by
1265: ** [sqlite3_shutdown()] and should deallocate any resources acquired
1266: ** by xInit. The pAppData pointer is used as the only parameter to
1267: ** xInit and xShutdown.
1268: **
1269: ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1270: ** the xInit method, so the xInit method need not be threadsafe. The
1271: ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1272: ** not need to be threadsafe either. For all other methods, SQLite
1273: ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1274: ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1275: ** it is by default) and so the methods are automatically serialized.
1276: ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1277: ** methods must be threadsafe or else make their own arrangements for
1278: ** serialization.
1279: **
1280: ** SQLite will never invoke xInit() more than once without an intervening
1281: ** call to xShutdown().
1282: */
1283: typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1284: struct sqlite3_mem_methods {
1285: void *(*xMalloc)(int); /* Memory allocation function */
1286: void (*xFree)(void*); /* Free a prior allocation */
1287: void *(*xRealloc)(void*,int); /* Resize an allocation */
1288: int (*xSize)(void*); /* Return the size of an allocation */
1289: int (*xRoundup)(int); /* Round up request size to allocation size */
1290: int (*xInit)(void*); /* Initialize the memory allocator */
1291: void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1292: void *pAppData; /* Argument to xInit() and xShutdown() */
1293: };
1294:
1295: /*
1296: ** CAPI3REF: Configuration Options
1297: ** KEYWORDS: {configuration option}
1298: **
1299: ** These constants are the available integer configuration options that
1300: ** can be passed as the first argument to the [sqlite3_config()] interface.
1301: **
1302: ** New configuration options may be added in future releases of SQLite.
1303: ** Existing configuration options might be discontinued. Applications
1304: ** should check the return code from [sqlite3_config()] to make sure that
1305: ** the call worked. The [sqlite3_config()] interface will return a
1306: ** non-zero [error code] if a discontinued or unsupported configuration option
1307: ** is invoked.
1308: **
1309: ** <dl>
1310: ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1311: ** <dd>There are no arguments to this option. ^This option sets the
1312: ** [threading mode] to Single-thread. In other words, it disables
1313: ** all mutexing and puts SQLite into a mode where it can only be used
1314: ** by a single thread. ^If SQLite is compiled with
1315: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1316: ** it is not possible to change the [threading mode] from its default
1317: ** value of Single-thread and so [sqlite3_config()] will return
1318: ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1319: ** configuration option.</dd>
1320: **
1321: ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1322: ** <dd>There are no arguments to this option. ^This option sets the
1323: ** [threading mode] to Multi-thread. In other words, it disables
1324: ** mutexing on [database connection] and [prepared statement] objects.
1325: ** The application is responsible for serializing access to
1326: ** [database connections] and [prepared statements]. But other mutexes
1327: ** are enabled so that SQLite will be safe to use in a multi-threaded
1328: ** environment as long as no two threads attempt to use the same
1329: ** [database connection] at the same time. ^If SQLite is compiled with
1330: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1331: ** it is not possible to set the Multi-thread [threading mode] and
1332: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1333: ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1334: **
1335: ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1336: ** <dd>There are no arguments to this option. ^This option sets the
1337: ** [threading mode] to Serialized. In other words, this option enables
1338: ** all mutexes including the recursive
1339: ** mutexes on [database connection] and [prepared statement] objects.
1340: ** In this mode (which is the default when SQLite is compiled with
1341: ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1342: ** to [database connections] and [prepared statements] so that the
1343: ** application is free to use the same [database connection] or the
1344: ** same [prepared statement] in different threads at the same time.
1345: ** ^If SQLite is compiled with
1346: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1347: ** it is not possible to set the Serialized [threading mode] and
1348: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1349: ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1350: **
1351: ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1352: ** <dd> ^(This option takes a single argument which is a pointer to an
1353: ** instance of the [sqlite3_mem_methods] structure. The argument specifies
1354: ** alternative low-level memory allocation routines to be used in place of
1355: ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1356: ** its own private copy of the content of the [sqlite3_mem_methods] structure
1357: ** before the [sqlite3_config()] call returns.</dd>
1358: **
1359: ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1360: ** <dd> ^(This option takes a single argument which is a pointer to an
1361: ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods]
1362: ** structure is filled with the currently defined memory allocation routines.)^
1363: ** This option can be used to overload the default memory allocation
1364: ** routines with a wrapper that simulations memory allocation failure or
1365: ** tracks memory usage, for example. </dd>
1366: **
1367: ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1368: ** <dd> ^This option takes single argument of type int, interpreted as a
1369: ** boolean, which enables or disables the collection of memory allocation
1370: ** statistics. ^(When memory allocation statistics are disabled, the
1371: ** following SQLite interfaces become non-operational:
1372: ** <ul>
1373: ** <li> [sqlite3_memory_used()]
1374: ** <li> [sqlite3_memory_highwater()]
1375: ** <li> [sqlite3_soft_heap_limit64()]
1376: ** <li> [sqlite3_status()]
1377: ** </ul>)^
1378: ** ^Memory allocation statistics are enabled by default unless SQLite is
1379: ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1380: ** allocation statistics are disabled by default.
1381: ** </dd>
1382: **
1383: ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1384: ** <dd> ^This option specifies a static memory buffer that SQLite can use for
1385: ** scratch memory. There are three arguments: A pointer an 8-byte
1386: ** aligned memory buffer from which the scratch allocations will be
1387: ** drawn, the size of each scratch allocation (sz),
1388: ** and the maximum number of scratch allocations (N). The sz
1389: ** argument must be a multiple of 16.
1390: ** The first argument must be a pointer to an 8-byte aligned buffer
1391: ** of at least sz*N bytes of memory.
1392: ** ^SQLite will use no more than two scratch buffers per thread. So
1393: ** N should be set to twice the expected maximum number of threads.
1394: ** ^SQLite will never require a scratch buffer that is more than 6
1395: ** times the database page size. ^If SQLite needs needs additional
1396: ** scratch memory beyond what is provided by this configuration option, then
1397: ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
1398: **
1399: ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1400: ** <dd> ^This option specifies a static memory buffer that SQLite can use for
1401: ** the database page cache with the default page cache implementation.
1402: ** This configuration should not be used if an application-define page
1403: ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.
1404: ** There are three arguments to this option: A pointer to 8-byte aligned
1405: ** memory, the size of each page buffer (sz), and the number of pages (N).
1406: ** The sz argument should be the size of the largest database page
1407: ** (a power of two between 512 and 32768) plus a little extra for each
1408: ** page header. ^The page header size is 20 to 40 bytes depending on
1409: ** the host architecture. ^It is harmless, apart from the wasted memory,
1410: ** to make sz a little too large. The first
1411: ** argument should point to an allocation of at least sz*N bytes of memory.
1412: ** ^SQLite will use the memory provided by the first argument to satisfy its
1413: ** memory needs for the first N pages that it adds to cache. ^If additional
1414: ** page cache memory is needed beyond what is provided by this option, then
1415: ** SQLite goes to [sqlite3_malloc()] for the additional storage space.
1416: ** The pointer in the first argument must
1417: ** be aligned to an 8-byte boundary or subsequent behavior of SQLite
1418: ** will be undefined.</dd>
1419: **
1420: ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1421: ** <dd> ^This option specifies a static memory buffer that SQLite will use
1422: ** for all of its dynamic memory allocation needs beyond those provided
1423: ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
1424: ** There are three arguments: An 8-byte aligned pointer to the memory,
1425: ** the number of bytes in the memory buffer, and the minimum allocation size.
1426: ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1427: ** to using its default memory allocator (the system malloc() implementation),
1428: ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1429: ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1430: ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
1431: ** allocator is engaged to handle all of SQLites memory allocation needs.
1432: ** The first pointer (the memory pointer) must be aligned to an 8-byte
1433: ** boundary or subsequent behavior of SQLite will be undefined.
1434: ** The minimum allocation size is capped at 2**12. Reasonable values
1435: ** for the minimum allocation size are 2**5 through 2**8.</dd>
1436: **
1437: ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1438: ** <dd> ^(This option takes a single argument which is a pointer to an
1439: ** instance of the [sqlite3_mutex_methods] structure. The argument specifies
1440: ** alternative low-level mutex routines to be used in place
1441: ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the
1442: ** content of the [sqlite3_mutex_methods] structure before the call to
1443: ** [sqlite3_config()] returns. ^If SQLite is compiled with
1444: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1445: ** the entire mutexing subsystem is omitted from the build and hence calls to
1446: ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1447: ** return [SQLITE_ERROR].</dd>
1448: **
1449: ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1450: ** <dd> ^(This option takes a single argument which is a pointer to an
1451: ** instance of the [sqlite3_mutex_methods] structure. The
1452: ** [sqlite3_mutex_methods]
1453: ** structure is filled with the currently defined mutex routines.)^
1454: ** This option can be used to overload the default mutex allocation
1455: ** routines with a wrapper used to track mutex usage for performance
1456: ** profiling or testing, for example. ^If SQLite is compiled with
1457: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1458: ** the entire mutexing subsystem is omitted from the build and hence calls to
1459: ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1460: ** return [SQLITE_ERROR].</dd>
1461: **
1462: ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1463: ** <dd> ^(This option takes two arguments that determine the default
1464: ** memory allocation for the lookaside memory allocator on each
1465: ** [database connection]. The first argument is the
1466: ** size of each lookaside buffer slot and the second is the number of
1467: ** slots allocated to each database connection.)^ ^(This option sets the
1468: ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1469: ** verb to [sqlite3_db_config()] can be used to change the lookaside
1470: ** configuration on individual connections.)^ </dd>
1471: **
1472: ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1473: ** <dd> ^(This option takes a single argument which is a pointer to
1474: ** an [sqlite3_pcache_methods2] object. This object specifies the interface
1475: ** to a custom page cache implementation.)^ ^SQLite makes a copy of the
1476: ** object and uses it for page cache memory allocations.</dd>
1477: **
1478: ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1479: ** <dd> ^(This option takes a single argument which is a pointer to an
1480: ** [sqlite3_pcache_methods2] object. SQLite copies of the current
1481: ** page cache implementation into that object.)^ </dd>
1482: **
1483: ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1484: ** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1485: ** function with a call signature of void(*)(void*,int,const char*),
1486: ** and a pointer to void. ^If the function pointer is not NULL, it is
1487: ** invoked by [sqlite3_log()] to process each logging event. ^If the
1488: ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1489: ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1490: ** passed through as the first parameter to the application-defined logger
1491: ** function whenever that function is invoked. ^The second parameter to
1492: ** the logger function is a copy of the first parameter to the corresponding
1493: ** [sqlite3_log()] call and is intended to be a [result code] or an
1494: ** [extended result code]. ^The third parameter passed to the logger is
1495: ** log message after formatting via [sqlite3_snprintf()].
1496: ** The SQLite logging interface is not reentrant; the logger function
1497: ** supplied by the application must not invoke any SQLite interface.
1498: ** In a multi-threaded application, the application-defined logger
1499: ** function must be threadsafe. </dd>
1500: **
1501: ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1502: ** <dd> This option takes a single argument of type int. If non-zero, then
1503: ** URI handling is globally enabled. If the parameter is zero, then URI handling
1504: ** is globally disabled. If URI handling is globally enabled, all filenames
1505: ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
1506: ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1507: ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1508: ** connection is opened. If it is globally disabled, filenames are
1509: ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1510: ** database connection is opened. By default, URI handling is globally
1511: ** disabled. The default value may be changed by compiling with the
1512: ** [SQLITE_USE_URI] symbol defined.
1513: **
1514: ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1515: ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFNIG_GETPCACHE
1516: ** <dd> These options are obsolete and should not be used by new code.
1517: ** They are retained for backwards compatibility but are now no-ops.
1518: ** </dl>
1519: */
1520: #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1521: #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1522: #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1523: #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1524: #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1525: #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
1526: #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1527: #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1528: #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1529: #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1530: #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1531: /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1532: #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1533: #define SQLITE_CONFIG_PCACHE 14 /* no-op */
1534: #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
1535: #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1536: #define SQLITE_CONFIG_URI 17 /* int */
1537: #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
1538: #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1539:
1540: /*
1541: ** CAPI3REF: Database Connection Configuration Options
1542: **
1543: ** These constants are the available integer configuration options that
1544: ** can be passed as the second argument to the [sqlite3_db_config()] interface.
1545: **
1546: ** New configuration options may be added in future releases of SQLite.
1547: ** Existing configuration options might be discontinued. Applications
1548: ** should check the return code from [sqlite3_db_config()] to make sure that
1549: ** the call worked. ^The [sqlite3_db_config()] interface will return a
1550: ** non-zero [error code] if a discontinued or unsupported configuration option
1551: ** is invoked.
1552: **
1553: ** <dl>
1554: ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1555: ** <dd> ^This option takes three additional arguments that determine the
1556: ** [lookaside memory allocator] configuration for the [database connection].
1557: ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1558: ** pointer to a memory buffer to use for lookaside memory.
1559: ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1560: ** may be NULL in which case SQLite will allocate the
1561: ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1562: ** size of each lookaside buffer slot. ^The third argument is the number of
1563: ** slots. The size of the buffer in the first argument must be greater than
1564: ** or equal to the product of the second and third arguments. The buffer
1565: ** must be aligned to an 8-byte boundary. ^If the second argument to
1566: ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1567: ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
1568: ** configuration for a database connection can only be changed when that
1569: ** connection is not currently using lookaside memory, or in other words
1570: ** when the "current value" returned by
1571: ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1572: ** Any attempt to change the lookaside memory configuration when lookaside
1573: ** memory is in use leaves the configuration unchanged and returns
1574: ** [SQLITE_BUSY].)^</dd>
1575: **
1576: ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
1577: ** <dd> ^This option is used to enable or disable the enforcement of
1578: ** [foreign key constraints]. There should be two additional arguments.
1579: ** The first argument is an integer which is 0 to disable FK enforcement,
1580: ** positive to enable FK enforcement or negative to leave FK enforcement
1581: ** unchanged. The second parameter is a pointer to an integer into which
1582: ** is written 0 or 1 to indicate whether FK enforcement is off or on
1583: ** following this call. The second parameter may be a NULL pointer, in
1584: ** which case the FK enforcement setting is not reported back. </dd>
1585: **
1586: ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
1587: ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
1588: ** There should be two additional arguments.
1589: ** The first argument is an integer which is 0 to disable triggers,
1590: ** positive to enable triggers or negative to leave the setting unchanged.
1591: ** The second parameter is a pointer to an integer into which
1592: ** is written 0 or 1 to indicate whether triggers are disabled or enabled
1593: ** following this call. The second parameter may be a NULL pointer, in
1594: ** which case the trigger setting is not reported back. </dd>
1595: **
1596: ** </dl>
1597: */
1598: #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
1599: #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
1600: #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
1601:
1602:
1603: /*
1604: ** CAPI3REF: Enable Or Disable Extended Result Codes
1605: **
1606: ** ^The sqlite3_extended_result_codes() routine enables or disables the
1607: ** [extended result codes] feature of SQLite. ^The extended result
1608: ** codes are disabled by default for historical compatibility.
1609: */
1610: SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
1611:
1612: /*
1613: ** CAPI3REF: Last Insert Rowid
1614: **
1615: ** ^Each entry in an SQLite table has a unique 64-bit signed
1616: ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
1617: ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
1618: ** names are not also used by explicitly declared columns. ^If
1619: ** the table has a column of type [INTEGER PRIMARY KEY] then that column
1620: ** is another alias for the rowid.
1621: **
1622: ** ^This routine returns the [rowid] of the most recent
1623: ** successful [INSERT] into the database from the [database connection]
1624: ** in the first argument. ^As of SQLite version 3.7.7, this routines
1625: ** records the last insert rowid of both ordinary tables and [virtual tables].
1626: ** ^If no successful [INSERT]s
1627: ** have ever occurred on that database connection, zero is returned.
1628: **
1629: ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
1630: ** method, then this routine will return the [rowid] of the inserted
1631: ** row as long as the trigger or virtual table method is running.
1632: ** But once the trigger or virtual table method ends, the value returned
1633: ** by this routine reverts to what it was before the trigger or virtual
1634: ** table method began.)^
1635: **
1636: ** ^An [INSERT] that fails due to a constraint violation is not a
1637: ** successful [INSERT] and does not change the value returned by this
1638: ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
1639: ** and INSERT OR ABORT make no changes to the return value of this
1640: ** routine when their insertion fails. ^(When INSERT OR REPLACE
1641: ** encounters a constraint violation, it does not fail. The
1642: ** INSERT continues to completion after deleting rows that caused
1643: ** the constraint problem so INSERT OR REPLACE will always change
1644: ** the return value of this interface.)^
1645: **
1646: ** ^For the purposes of this routine, an [INSERT] is considered to
1647: ** be successful even if it is subsequently rolled back.
1648: **
1649: ** This function is accessible to SQL statements via the
1650: ** [last_insert_rowid() SQL function].
1651: **
1652: ** If a separate thread performs a new [INSERT] on the same
1653: ** database connection while the [sqlite3_last_insert_rowid()]
1654: ** function is running and thus changes the last insert [rowid],
1655: ** then the value returned by [sqlite3_last_insert_rowid()] is
1656: ** unpredictable and might not equal either the old or the new
1657: ** last insert [rowid].
1658: */
1659: SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
1660:
1661: /*
1662: ** CAPI3REF: Count The Number Of Rows Modified
1663: **
1664: ** ^This function returns the number of database rows that were changed
1665: ** or inserted or deleted by the most recently completed SQL statement
1666: ** on the [database connection] specified by the first parameter.
1667: ** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
1668: ** or [DELETE] statement are counted. Auxiliary changes caused by
1669: ** triggers or [foreign key actions] are not counted.)^ Use the
1670: ** [sqlite3_total_changes()] function to find the total number of changes
1671: ** including changes caused by triggers and foreign key actions.
1672: **
1673: ** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
1674: ** are not counted. Only real table changes are counted.
1675: **
1676: ** ^(A "row change" is a change to a single row of a single table
1677: ** caused by an INSERT, DELETE, or UPDATE statement. Rows that
1678: ** are changed as side effects of [REPLACE] constraint resolution,
1679: ** rollback, ABORT processing, [DROP TABLE], or by any other
1680: ** mechanisms do not count as direct row changes.)^
1681: **
1682: ** A "trigger context" is a scope of execution that begins and
1683: ** ends with the script of a [CREATE TRIGGER | trigger].
1684: ** Most SQL statements are
1685: ** evaluated outside of any trigger. This is the "top level"
1686: ** trigger context. If a trigger fires from the top level, a
1687: ** new trigger context is entered for the duration of that one
1688: ** trigger. Subtriggers create subcontexts for their duration.
1689: **
1690: ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
1691: ** not create a new trigger context.
1692: **
1693: ** ^This function returns the number of direct row changes in the
1694: ** most recent INSERT, UPDATE, or DELETE statement within the same
1695: ** trigger context.
1696: **
1697: ** ^Thus, when called from the top level, this function returns the
1698: ** number of changes in the most recent INSERT, UPDATE, or DELETE
1699: ** that also occurred at the top level. ^(Within the body of a trigger,
1700: ** the sqlite3_changes() interface can be called to find the number of
1701: ** changes in the most recently completed INSERT, UPDATE, or DELETE
1702: ** statement within the body of the same trigger.
1703: ** However, the number returned does not include changes
1704: ** caused by subtriggers since those have their own context.)^
1705: **
1706: ** See also the [sqlite3_total_changes()] interface, the
1707: ** [count_changes pragma], and the [changes() SQL function].
1708: **
1709: ** If a separate thread makes changes on the same database connection
1710: ** while [sqlite3_changes()] is running then the value returned
1711: ** is unpredictable and not meaningful.
1712: */
1713: SQLITE_API int sqlite3_changes(sqlite3*);
1714:
1715: /*
1716: ** CAPI3REF: Total Number Of Rows Modified
1717: **
1718: ** ^This function returns the number of row changes caused by [INSERT],
1719: ** [UPDATE] or [DELETE] statements since the [database connection] was opened.
1720: ** ^(The count returned by sqlite3_total_changes() includes all changes
1721: ** from all [CREATE TRIGGER | trigger] contexts and changes made by
1722: ** [foreign key actions]. However,
1723: ** the count does not include changes used to implement [REPLACE] constraints,
1724: ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The
1725: ** count does not include rows of views that fire an [INSTEAD OF trigger],
1726: ** though if the INSTEAD OF trigger makes changes of its own, those changes
1727: ** are counted.)^
1728: ** ^The sqlite3_total_changes() function counts the changes as soon as
1729: ** the statement that makes them is completed (when the statement handle
1730: ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
1731: **
1732: ** See also the [sqlite3_changes()] interface, the
1733: ** [count_changes pragma], and the [total_changes() SQL function].
1734: **
1735: ** If a separate thread makes changes on the same database connection
1736: ** while [sqlite3_total_changes()] is running then the value
1737: ** returned is unpredictable and not meaningful.
1738: */
1739: SQLITE_API int sqlite3_total_changes(sqlite3*);
1740:
1741: /*
1742: ** CAPI3REF: Interrupt A Long-Running Query
1743: **
1744: ** ^This function causes any pending database operation to abort and
1745: ** return at its earliest opportunity. This routine is typically
1746: ** called in response to a user action such as pressing "Cancel"
1747: ** or Ctrl-C where the user wants a long query operation to halt
1748: ** immediately.
1749: **
1750: ** ^It is safe to call this routine from a thread different from the
1751: ** thread that is currently running the database operation. But it
1752: ** is not safe to call this routine with a [database connection] that
1753: ** is closed or might close before sqlite3_interrupt() returns.
1754: **
1755: ** ^If an SQL operation is very nearly finished at the time when
1756: ** sqlite3_interrupt() is called, then it might not have an opportunity
1757: ** to be interrupted and might continue to completion.
1758: **
1759: ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
1760: ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
1761: ** that is inside an explicit transaction, then the entire transaction
1762: ** will be rolled back automatically.
1763: **
1764: ** ^The sqlite3_interrupt(D) call is in effect until all currently running
1765: ** SQL statements on [database connection] D complete. ^Any new SQL statements
1766: ** that are started after the sqlite3_interrupt() call and before the
1767: ** running statements reaches zero are interrupted as if they had been
1768: ** running prior to the sqlite3_interrupt() call. ^New SQL statements
1769: ** that are started after the running statement count reaches zero are
1770: ** not effected by the sqlite3_interrupt().
1771: ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
1772: ** SQL statements is a no-op and has no effect on SQL statements
1773: ** that are started after the sqlite3_interrupt() call returns.
1774: **
1775: ** If the database connection closes while [sqlite3_interrupt()]
1776: ** is running then bad things will likely happen.
1777: */
1778: SQLITE_API void sqlite3_interrupt(sqlite3*);
1779:
1780: /*
1781: ** CAPI3REF: Determine If An SQL Statement Is Complete
1782: **
1783: ** These routines are useful during command-line input to determine if the
1784: ** currently entered text seems to form a complete SQL statement or
1785: ** if additional input is needed before sending the text into
1786: ** SQLite for parsing. ^These routines return 1 if the input string
1787: ** appears to be a complete SQL statement. ^A statement is judged to be
1788: ** complete if it ends with a semicolon token and is not a prefix of a
1789: ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
1790: ** string literals or quoted identifier names or comments are not
1791: ** independent tokens (they are part of the token in which they are
1792: ** embedded) and thus do not count as a statement terminator. ^Whitespace
1793: ** and comments that follow the final semicolon are ignored.
1794: **
1795: ** ^These routines return 0 if the statement is incomplete. ^If a
1796: ** memory allocation fails, then SQLITE_NOMEM is returned.
1797: **
1798: ** ^These routines do not parse the SQL statements thus
1799: ** will not detect syntactically incorrect SQL.
1800: **
1801: ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
1802: ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
1803: ** automatically by sqlite3_complete16(). If that initialization fails,
1804: ** then the return value from sqlite3_complete16() will be non-zero
1805: ** regardless of whether or not the input SQL is complete.)^
1806: **
1807: ** The input to [sqlite3_complete()] must be a zero-terminated
1808: ** UTF-8 string.
1809: **
1810: ** The input to [sqlite3_complete16()] must be a zero-terminated
1811: ** UTF-16 string in native byte order.
1812: */
1813: SQLITE_API int sqlite3_complete(const char *sql);
1814: SQLITE_API int sqlite3_complete16(const void *sql);
1815:
1816: /*
1817: ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
1818: **
1819: ** ^This routine sets a callback function that might be invoked whenever
1820: ** an attempt is made to open a database table that another thread
1821: ** or process has locked.
1822: **
1823: ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
1824: ** is returned immediately upon encountering the lock. ^If the busy callback
1825: ** is not NULL, then the callback might be invoked with two arguments.
1826: **
1827: ** ^The first argument to the busy handler is a copy of the void* pointer which
1828: ** is the third argument to sqlite3_busy_handler(). ^The second argument to
1829: ** the busy handler callback is the number of times that the busy handler has
1830: ** been invoked for this locking event. ^If the
1831: ** busy callback returns 0, then no additional attempts are made to
1832: ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
1833: ** ^If the callback returns non-zero, then another attempt
1834: ** is made to open the database for reading and the cycle repeats.
1835: **
1836: ** The presence of a busy handler does not guarantee that it will be invoked
1837: ** when there is lock contention. ^If SQLite determines that invoking the busy
1838: ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
1839: ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
1840: ** Consider a scenario where one process is holding a read lock that
1841: ** it is trying to promote to a reserved lock and
1842: ** a second process is holding a reserved lock that it is trying
1843: ** to promote to an exclusive lock. The first process cannot proceed
1844: ** because it is blocked by the second and the second process cannot
1845: ** proceed because it is blocked by the first. If both processes
1846: ** invoke the busy handlers, neither will make any progress. Therefore,
1847: ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
1848: ** will induce the first process to release its read lock and allow
1849: ** the second process to proceed.
1850: **
1851: ** ^The default busy callback is NULL.
1852: **
1853: ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
1854: ** when SQLite is in the middle of a large transaction where all the
1855: ** changes will not fit into the in-memory cache. SQLite will
1856: ** already hold a RESERVED lock on the database file, but it needs
1857: ** to promote this lock to EXCLUSIVE so that it can spill cache
1858: ** pages into the database file without harm to concurrent
1859: ** readers. ^If it is unable to promote the lock, then the in-memory
1860: ** cache will be left in an inconsistent state and so the error
1861: ** code is promoted from the relatively benign [SQLITE_BUSY] to
1862: ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion
1863: ** forces an automatic rollback of the changes. See the
1864: ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
1865: ** CorruptionFollowingBusyError</a> wiki page for a discussion of why
1866: ** this is important.
1867: **
1868: ** ^(There can only be a single busy handler defined for each
1869: ** [database connection]. Setting a new busy handler clears any
1870: ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
1871: ** will also set or clear the busy handler.
1872: **
1873: ** The busy callback should not take any actions which modify the
1874: ** database connection that invoked the busy handler. Any such actions
1875: ** result in undefined behavior.
1876: **
1877: ** A busy handler must not close the database connection
1878: ** or [prepared statement] that invoked the busy handler.
1879: */
1880: SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
1881:
1882: /*
1883: ** CAPI3REF: Set A Busy Timeout
1884: **
1885: ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
1886: ** for a specified amount of time when a table is locked. ^The handler
1887: ** will sleep multiple times until at least "ms" milliseconds of sleeping
1888: ** have accumulated. ^After at least "ms" milliseconds of sleeping,
1889: ** the handler returns 0 which causes [sqlite3_step()] to return
1890: ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
1891: **
1892: ** ^Calling this routine with an argument less than or equal to zero
1893: ** turns off all busy handlers.
1894: **
1895: ** ^(There can only be a single busy handler for a particular
1896: ** [database connection] any any given moment. If another busy handler
1897: ** was defined (using [sqlite3_busy_handler()]) prior to calling
1898: ** this routine, that other busy handler is cleared.)^
1899: */
1900: SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
1901:
1902: /*
1903: ** CAPI3REF: Convenience Routines For Running Queries
1904: **
1905: ** This is a legacy interface that is preserved for backwards compatibility.
1906: ** Use of this interface is not recommended.
1907: **
1908: ** Definition: A <b>result table</b> is memory data structure created by the
1909: ** [sqlite3_get_table()] interface. A result table records the
1910: ** complete query results from one or more queries.
1911: **
1912: ** The table conceptually has a number of rows and columns. But
1913: ** these numbers are not part of the result table itself. These
1914: ** numbers are obtained separately. Let N be the number of rows
1915: ** and M be the number of columns.
1916: **
1917: ** A result table is an array of pointers to zero-terminated UTF-8 strings.
1918: ** There are (N+1)*M elements in the array. The first M pointers point
1919: ** to zero-terminated strings that contain the names of the columns.
1920: ** The remaining entries all point to query results. NULL values result
1921: ** in NULL pointers. All other values are in their UTF-8 zero-terminated
1922: ** string representation as returned by [sqlite3_column_text()].
1923: **
1924: ** A result table might consist of one or more memory allocations.
1925: ** It is not safe to pass a result table directly to [sqlite3_free()].
1926: ** A result table should be deallocated using [sqlite3_free_table()].
1927: **
1928: ** ^(As an example of the result table format, suppose a query result
1929: ** is as follows:
1930: **
1931: ** <blockquote><pre>
1932: ** Name | Age
1933: ** -----------------------
1934: ** Alice | 43
1935: ** Bob | 28
1936: ** Cindy | 21
1937: ** </pre></blockquote>
1938: **
1939: ** There are two column (M==2) and three rows (N==3). Thus the
1940: ** result table has 8 entries. Suppose the result table is stored
1941: ** in an array names azResult. Then azResult holds this content:
1942: **
1943: ** <blockquote><pre>
1944: ** azResult[0] = "Name";
1945: ** azResult[1] = "Age";
1946: ** azResult[2] = "Alice";
1947: ** azResult[3] = "43";
1948: ** azResult[4] = "Bob";
1949: ** azResult[5] = "28";
1950: ** azResult[6] = "Cindy";
1951: ** azResult[7] = "21";
1952: ** </pre></blockquote>)^
1953: **
1954: ** ^The sqlite3_get_table() function evaluates one or more
1955: ** semicolon-separated SQL statements in the zero-terminated UTF-8
1956: ** string of its 2nd parameter and returns a result table to the
1957: ** pointer given in its 3rd parameter.
1958: **
1959: ** After the application has finished with the result from sqlite3_get_table(),
1960: ** it must pass the result table pointer to sqlite3_free_table() in order to
1961: ** release the memory that was malloced. Because of the way the
1962: ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
1963: ** function must not try to call [sqlite3_free()] directly. Only
1964: ** [sqlite3_free_table()] is able to release the memory properly and safely.
1965: **
1966: ** The sqlite3_get_table() interface is implemented as a wrapper around
1967: ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
1968: ** to any internal data structures of SQLite. It uses only the public
1969: ** interface defined here. As a consequence, errors that occur in the
1970: ** wrapper layer outside of the internal [sqlite3_exec()] call are not
1971: ** reflected in subsequent calls to [sqlite3_errcode()] or
1972: ** [sqlite3_errmsg()].
1973: */
1974: SQLITE_API int sqlite3_get_table(
1975: sqlite3 *db, /* An open database */
1976: const char *zSql, /* SQL to be evaluated */
1977: char ***pazResult, /* Results of the query */
1978: int *pnRow, /* Number of result rows written here */
1979: int *pnColumn, /* Number of result columns written here */
1980: char **pzErrmsg /* Error msg written here */
1981: );
1982: SQLITE_API void sqlite3_free_table(char **result);
1983:
1984: /*
1985: ** CAPI3REF: Formatted String Printing Functions
1986: **
1987: ** These routines are work-alikes of the "printf()" family of functions
1988: ** from the standard C library.
1989: **
1990: ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
1991: ** results into memory obtained from [sqlite3_malloc()].
1992: ** The strings returned by these two routines should be
1993: ** released by [sqlite3_free()]. ^Both routines return a
1994: ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
1995: ** memory to hold the resulting string.
1996: **
1997: ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
1998: ** the standard C library. The result is written into the
1999: ** buffer supplied as the second parameter whose size is given by
2000: ** the first parameter. Note that the order of the
2001: ** first two parameters is reversed from snprintf().)^ This is an
2002: ** historical accident that cannot be fixed without breaking
2003: ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2004: ** returns a pointer to its buffer instead of the number of
2005: ** characters actually written into the buffer.)^ We admit that
2006: ** the number of characters written would be a more useful return
2007: ** value but we cannot change the implementation of sqlite3_snprintf()
2008: ** now without breaking compatibility.
2009: **
2010: ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2011: ** guarantees that the buffer is always zero-terminated. ^The first
2012: ** parameter "n" is the total size of the buffer, including space for
2013: ** the zero terminator. So the longest string that can be completely
2014: ** written will be n-1 characters.
2015: **
2016: ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2017: **
2018: ** These routines all implement some additional formatting
2019: ** options that are useful for constructing SQL statements.
2020: ** All of the usual printf() formatting options apply. In addition, there
2021: ** is are "%q", "%Q", and "%z" options.
2022: **
2023: ** ^(The %q option works like %s in that it substitutes a nul-terminated
2024: ** string from the argument list. But %q also doubles every '\'' character.
2025: ** %q is designed for use inside a string literal.)^ By doubling each '\''
2026: ** character it escapes that character and allows it to be inserted into
2027: ** the string.
2028: **
2029: ** For example, assume the string variable zText contains text as follows:
2030: **
2031: ** <blockquote><pre>
2032: ** char *zText = "It's a happy day!";
2033: ** </pre></blockquote>
2034: **
2035: ** One can use this text in an SQL statement as follows:
2036: **
2037: ** <blockquote><pre>
2038: ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2039: ** sqlite3_exec(db, zSQL, 0, 0, 0);
2040: ** sqlite3_free(zSQL);
2041: ** </pre></blockquote>
2042: **
2043: ** Because the %q format string is used, the '\'' character in zText
2044: ** is escaped and the SQL generated is as follows:
2045: **
2046: ** <blockquote><pre>
2047: ** INSERT INTO table1 VALUES('It''s a happy day!')
2048: ** </pre></blockquote>
2049: **
2050: ** This is correct. Had we used %s instead of %q, the generated SQL
2051: ** would have looked like this:
2052: **
2053: ** <blockquote><pre>
2054: ** INSERT INTO table1 VALUES('It's a happy day!');
2055: ** </pre></blockquote>
2056: **
2057: ** This second example is an SQL syntax error. As a general rule you should
2058: ** always use %q instead of %s when inserting text into a string literal.
2059: **
2060: ** ^(The %Q option works like %q except it also adds single quotes around
2061: ** the outside of the total string. Additionally, if the parameter in the
2062: ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2063: ** single quotes).)^ So, for example, one could say:
2064: **
2065: ** <blockquote><pre>
2066: ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2067: ** sqlite3_exec(db, zSQL, 0, 0, 0);
2068: ** sqlite3_free(zSQL);
2069: ** </pre></blockquote>
2070: **
2071: ** The code above will render a correct SQL statement in the zSQL
2072: ** variable even if the zText variable is a NULL pointer.
2073: **
2074: ** ^(The "%z" formatting option works like "%s" but with the
2075: ** addition that after the string has been read and copied into
2076: ** the result, [sqlite3_free()] is called on the input string.)^
2077: */
2078: SQLITE_API char *sqlite3_mprintf(const char*,...);
2079: SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2080: SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2081: SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2082:
2083: /*
2084: ** CAPI3REF: Memory Allocation Subsystem
2085: **
2086: ** The SQLite core uses these three routines for all of its own
2087: ** internal memory allocation needs. "Core" in the previous sentence
2088: ** does not include operating-system specific VFS implementation. The
2089: ** Windows VFS uses native malloc() and free() for some operations.
2090: **
2091: ** ^The sqlite3_malloc() routine returns a pointer to a block
2092: ** of memory at least N bytes in length, where N is the parameter.
2093: ** ^If sqlite3_malloc() is unable to obtain sufficient free
2094: ** memory, it returns a NULL pointer. ^If the parameter N to
2095: ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2096: ** a NULL pointer.
2097: **
2098: ** ^Calling sqlite3_free() with a pointer previously returned
2099: ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2100: ** that it might be reused. ^The sqlite3_free() routine is
2101: ** a no-op if is called with a NULL pointer. Passing a NULL pointer
2102: ** to sqlite3_free() is harmless. After being freed, memory
2103: ** should neither be read nor written. Even reading previously freed
2104: ** memory might result in a segmentation fault or other severe error.
2105: ** Memory corruption, a segmentation fault, or other severe error
2106: ** might result if sqlite3_free() is called with a non-NULL pointer that
2107: ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2108: **
2109: ** ^(The sqlite3_realloc() interface attempts to resize a
2110: ** prior memory allocation to be at least N bytes, where N is the
2111: ** second parameter. The memory allocation to be resized is the first
2112: ** parameter.)^ ^ If the first parameter to sqlite3_realloc()
2113: ** is a NULL pointer then its behavior is identical to calling
2114: ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
2115: ** ^If the second parameter to sqlite3_realloc() is zero or
2116: ** negative then the behavior is exactly the same as calling
2117: ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
2118: ** ^sqlite3_realloc() returns a pointer to a memory allocation
2119: ** of at least N bytes in size or NULL if sufficient memory is unavailable.
2120: ** ^If M is the size of the prior allocation, then min(N,M) bytes
2121: ** of the prior allocation are copied into the beginning of buffer returned
2122: ** by sqlite3_realloc() and the prior allocation is freed.
2123: ** ^If sqlite3_realloc() returns NULL, then the prior allocation
2124: ** is not freed.
2125: **
2126: ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
2127: ** is always aligned to at least an 8 byte boundary, or to a
2128: ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2129: ** option is used.
2130: **
2131: ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2132: ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2133: ** implementation of these routines to be omitted. That capability
2134: ** is no longer provided. Only built-in memory allocators can be used.
2135: **
2136: ** The Windows OS interface layer calls
2137: ** the system malloc() and free() directly when converting
2138: ** filenames between the UTF-8 encoding used by SQLite
2139: ** and whatever filename encoding is used by the particular Windows
2140: ** installation. Memory allocation errors are detected, but
2141: ** they are reported back as [SQLITE_CANTOPEN] or
2142: ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2143: **
2144: ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2145: ** must be either NULL or else pointers obtained from a prior
2146: ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2147: ** not yet been released.
2148: **
2149: ** The application must not read or write any part of
2150: ** a block of memory after it has been released using
2151: ** [sqlite3_free()] or [sqlite3_realloc()].
2152: */
2153: SQLITE_API void *sqlite3_malloc(int);
2154: SQLITE_API void *sqlite3_realloc(void*, int);
2155: SQLITE_API void sqlite3_free(void*);
2156:
2157: /*
2158: ** CAPI3REF: Memory Allocator Statistics
2159: **
2160: ** SQLite provides these two interfaces for reporting on the status
2161: ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2162: ** routines, which form the built-in memory allocation subsystem.
2163: **
2164: ** ^The [sqlite3_memory_used()] routine returns the number of bytes
2165: ** of memory currently outstanding (malloced but not freed).
2166: ** ^The [sqlite3_memory_highwater()] routine returns the maximum
2167: ** value of [sqlite3_memory_used()] since the high-water mark
2168: ** was last reset. ^The values returned by [sqlite3_memory_used()] and
2169: ** [sqlite3_memory_highwater()] include any overhead
2170: ** added by SQLite in its implementation of [sqlite3_malloc()],
2171: ** but not overhead added by the any underlying system library
2172: ** routines that [sqlite3_malloc()] may call.
2173: **
2174: ** ^The memory high-water mark is reset to the current value of
2175: ** [sqlite3_memory_used()] if and only if the parameter to
2176: ** [sqlite3_memory_highwater()] is true. ^The value returned
2177: ** by [sqlite3_memory_highwater(1)] is the high-water mark
2178: ** prior to the reset.
2179: */
2180: SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2181: SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2182:
2183: /*
2184: ** CAPI3REF: Pseudo-Random Number Generator
2185: **
2186: ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2187: ** select random [ROWID | ROWIDs] when inserting new records into a table that
2188: ** already uses the largest possible [ROWID]. The PRNG is also used for
2189: ** the build-in random() and randomblob() SQL functions. This interface allows
2190: ** applications to access the same PRNG for other purposes.
2191: **
2192: ** ^A call to this routine stores N bytes of randomness into buffer P.
2193: **
2194: ** ^The first time this routine is invoked (either internally or by
2195: ** the application) the PRNG is seeded using randomness obtained
2196: ** from the xRandomness method of the default [sqlite3_vfs] object.
2197: ** ^On all subsequent invocations, the pseudo-randomness is generated
2198: ** internally and without recourse to the [sqlite3_vfs] xRandomness
2199: ** method.
2200: */
2201: SQLITE_API void sqlite3_randomness(int N, void *P);
2202:
2203: /*
2204: ** CAPI3REF: Compile-Time Authorization Callbacks
2205: **
2206: ** ^This routine registers an authorizer callback with a particular
2207: ** [database connection], supplied in the first argument.
2208: ** ^The authorizer callback is invoked as SQL statements are being compiled
2209: ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2210: ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
2211: ** points during the compilation process, as logic is being created
2212: ** to perform various actions, the authorizer callback is invoked to
2213: ** see if those actions are allowed. ^The authorizer callback should
2214: ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2215: ** specific action but allow the SQL statement to continue to be
2216: ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2217: ** rejected with an error. ^If the authorizer callback returns
2218: ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2219: ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2220: ** the authorizer will fail with an error message.
2221: **
2222: ** When the callback returns [SQLITE_OK], that means the operation
2223: ** requested is ok. ^When the callback returns [SQLITE_DENY], the
2224: ** [sqlite3_prepare_v2()] or equivalent call that triggered the
2225: ** authorizer will fail with an error message explaining that
2226: ** access is denied.
2227: **
2228: ** ^The first parameter to the authorizer callback is a copy of the third
2229: ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2230: ** to the callback is an integer [SQLITE_COPY | action code] that specifies
2231: ** the particular action to be authorized. ^The third through sixth parameters
2232: ** to the callback are zero-terminated strings that contain additional
2233: ** details about the action to be authorized.
2234: **
2235: ** ^If the action code is [SQLITE_READ]
2236: ** and the callback returns [SQLITE_IGNORE] then the
2237: ** [prepared statement] statement is constructed to substitute
2238: ** a NULL value in place of the table column that would have
2239: ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2240: ** return can be used to deny an untrusted user access to individual
2241: ** columns of a table.
2242: ** ^If the action code is [SQLITE_DELETE] and the callback returns
2243: ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2244: ** [truncate optimization] is disabled and all rows are deleted individually.
2245: **
2246: ** An authorizer is used when [sqlite3_prepare | preparing]
2247: ** SQL statements from an untrusted source, to ensure that the SQL statements
2248: ** do not try to access data they are not allowed to see, or that they do not
2249: ** try to execute malicious statements that damage the database. For
2250: ** example, an application may allow a user to enter arbitrary
2251: ** SQL queries for evaluation by a database. But the application does
2252: ** not want the user to be able to make arbitrary changes to the
2253: ** database. An authorizer could then be put in place while the
2254: ** user-entered SQL is being [sqlite3_prepare | prepared] that
2255: ** disallows everything except [SELECT] statements.
2256: **
2257: ** Applications that need to process SQL from untrusted sources
2258: ** might also consider lowering resource limits using [sqlite3_limit()]
2259: ** and limiting database size using the [max_page_count] [PRAGMA]
2260: ** in addition to using an authorizer.
2261: **
2262: ** ^(Only a single authorizer can be in place on a database connection
2263: ** at a time. Each call to sqlite3_set_authorizer overrides the
2264: ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2265: ** The authorizer is disabled by default.
2266: **
2267: ** The authorizer callback must not do anything that will modify
2268: ** the database connection that invoked the authorizer callback.
2269: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2270: ** database connections for the meaning of "modify" in this paragraph.
2271: **
2272: ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2273: ** statement might be re-prepared during [sqlite3_step()] due to a
2274: ** schema change. Hence, the application should ensure that the
2275: ** correct authorizer callback remains in place during the [sqlite3_step()].
2276: **
2277: ** ^Note that the authorizer callback is invoked only during
2278: ** [sqlite3_prepare()] or its variants. Authorization is not
2279: ** performed during statement evaluation in [sqlite3_step()], unless
2280: ** as stated in the previous paragraph, sqlite3_step() invokes
2281: ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2282: */
2283: SQLITE_API int sqlite3_set_authorizer(
2284: sqlite3*,
2285: int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2286: void *pUserData
2287: );
2288:
2289: /*
2290: ** CAPI3REF: Authorizer Return Codes
2291: **
2292: ** The [sqlite3_set_authorizer | authorizer callback function] must
2293: ** return either [SQLITE_OK] or one of these two constants in order
2294: ** to signal SQLite whether or not the action is permitted. See the
2295: ** [sqlite3_set_authorizer | authorizer documentation] for additional
2296: ** information.
2297: **
2298: ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
2299: ** from the [sqlite3_vtab_on_conflict()] interface.
2300: */
2301: #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2302: #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2303:
2304: /*
2305: ** CAPI3REF: Authorizer Action Codes
2306: **
2307: ** The [sqlite3_set_authorizer()] interface registers a callback function
2308: ** that is invoked to authorize certain SQL statement actions. The
2309: ** second parameter to the callback is an integer code that specifies
2310: ** what action is being authorized. These are the integer action codes that
2311: ** the authorizer callback may be passed.
2312: **
2313: ** These action code values signify what kind of operation is to be
2314: ** authorized. The 3rd and 4th parameters to the authorization
2315: ** callback function will be parameters or NULL depending on which of these
2316: ** codes is used as the second parameter. ^(The 5th parameter to the
2317: ** authorizer callback is the name of the database ("main", "temp",
2318: ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2319: ** is the name of the inner-most trigger or view that is responsible for
2320: ** the access attempt or NULL if this access attempt is directly from
2321: ** top-level SQL code.
2322: */
2323: /******************************************* 3rd ************ 4th ***********/
2324: #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2325: #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2326: #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2327: #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2328: #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2329: #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2330: #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2331: #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2332: #define SQLITE_DELETE 9 /* Table Name NULL */
2333: #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2334: #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2335: #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2336: #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2337: #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2338: #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2339: #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2340: #define SQLITE_DROP_VIEW 17 /* View Name NULL */
2341: #define SQLITE_INSERT 18 /* Table Name NULL */
2342: #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2343: #define SQLITE_READ 20 /* Table Name Column Name */
2344: #define SQLITE_SELECT 21 /* NULL NULL */
2345: #define SQLITE_TRANSACTION 22 /* Operation NULL */
2346: #define SQLITE_UPDATE 23 /* Table Name Column Name */
2347: #define SQLITE_ATTACH 24 /* Filename NULL */
2348: #define SQLITE_DETACH 25 /* Database Name NULL */
2349: #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2350: #define SQLITE_REINDEX 27 /* Index Name NULL */
2351: #define SQLITE_ANALYZE 28 /* Table Name NULL */
2352: #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2353: #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2354: #define SQLITE_FUNCTION 31 /* NULL Function Name */
2355: #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2356: #define SQLITE_COPY 0 /* No longer used */
2357:
2358: /*
2359: ** CAPI3REF: Tracing And Profiling Functions
2360: **
2361: ** These routines register callback functions that can be used for
2362: ** tracing and profiling the execution of SQL statements.
2363: **
2364: ** ^The callback function registered by sqlite3_trace() is invoked at
2365: ** various times when an SQL statement is being run by [sqlite3_step()].
2366: ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2367: ** SQL statement text as the statement first begins executing.
2368: ** ^(Additional sqlite3_trace() callbacks might occur
2369: ** as each triggered subprogram is entered. The callbacks for triggers
2370: ** contain a UTF-8 SQL comment that identifies the trigger.)^
2371: **
2372: ** ^The callback function registered by sqlite3_profile() is invoked
2373: ** as each SQL statement finishes. ^The profile callback contains
2374: ** the original statement text and an estimate of wall-clock time
2375: ** of how long that statement took to run. ^The profile callback
2376: ** time is in units of nanoseconds, however the current implementation
2377: ** is only capable of millisecond resolution so the six least significant
2378: ** digits in the time are meaningless. Future versions of SQLite
2379: ** might provide greater resolution on the profiler callback. The
2380: ** sqlite3_profile() function is considered experimental and is
2381: ** subject to change in future versions of SQLite.
2382: */
2383: SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2384: SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
2385: void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2386:
2387: /*
2388: ** CAPI3REF: Query Progress Callbacks
2389: **
2390: ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2391: ** function X to be invoked periodically during long running calls to
2392: ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2393: ** database connection D. An example use for this
2394: ** interface is to keep a GUI updated during a large query.
2395: **
2396: ** ^The parameter P is passed through as the only parameter to the
2397: ** callback function X. ^The parameter N is the number of
2398: ** [virtual machine instructions] that are evaluated between successive
2399: ** invocations of the callback X.
2400: **
2401: ** ^Only a single progress handler may be defined at one time per
2402: ** [database connection]; setting a new progress handler cancels the
2403: ** old one. ^Setting parameter X to NULL disables the progress handler.
2404: ** ^The progress handler is also disabled by setting N to a value less
2405: ** than 1.
2406: **
2407: ** ^If the progress callback returns non-zero, the operation is
2408: ** interrupted. This feature can be used to implement a
2409: ** "Cancel" button on a GUI progress dialog box.
2410: **
2411: ** The progress handler callback must not do anything that will modify
2412: ** the database connection that invoked the progress handler.
2413: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2414: ** database connections for the meaning of "modify" in this paragraph.
2415: **
2416: */
2417: SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2418:
2419: /*
2420: ** CAPI3REF: Opening A New Database Connection
2421: **
2422: ** ^These routines open an SQLite database file as specified by the
2423: ** filename argument. ^The filename argument is interpreted as UTF-8 for
2424: ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2425: ** order for sqlite3_open16(). ^(A [database connection] handle is usually
2426: ** returned in *ppDb, even if an error occurs. The only exception is that
2427: ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2428: ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2429: ** object.)^ ^(If the database is opened (and/or created) successfully, then
2430: ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
2431: ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2432: ** an English language description of the error following a failure of any
2433: ** of the sqlite3_open() routines.
2434: **
2435: ** ^The default encoding for the database will be UTF-8 if
2436: ** sqlite3_open() or sqlite3_open_v2() is called and
2437: ** UTF-16 in the native byte order if sqlite3_open16() is used.
2438: **
2439: ** Whether or not an error occurs when it is opened, resources
2440: ** associated with the [database connection] handle should be released by
2441: ** passing it to [sqlite3_close()] when it is no longer required.
2442: **
2443: ** The sqlite3_open_v2() interface works like sqlite3_open()
2444: ** except that it accepts two additional parameters for additional control
2445: ** over the new database connection. ^(The flags parameter to
2446: ** sqlite3_open_v2() can take one of
2447: ** the following three values, optionally combined with the
2448: ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
2449: ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
2450: **
2451: ** <dl>
2452: ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
2453: ** <dd>The database is opened in read-only mode. If the database does not
2454: ** already exist, an error is returned.</dd>)^
2455: **
2456: ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
2457: ** <dd>The database is opened for reading and writing if possible, or reading
2458: ** only if the file is write protected by the operating system. In either
2459: ** case the database must already exist, otherwise an error is returned.</dd>)^
2460: **
2461: ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
2462: ** <dd>The database is opened for reading and writing, and is created if
2463: ** it does not already exist. This is the behavior that is always used for
2464: ** sqlite3_open() and sqlite3_open16().</dd>)^
2465: ** </dl>
2466: **
2467: ** If the 3rd parameter to sqlite3_open_v2() is not one of the
2468: ** combinations shown above optionally combined with other
2469: ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
2470: ** then the behavior is undefined.
2471: **
2472: ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
2473: ** opens in the multi-thread [threading mode] as long as the single-thread
2474: ** mode has not been set at compile-time or start-time. ^If the
2475: ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2476: ** in the serialized [threading mode] unless single-thread was
2477: ** previously selected at compile-time or start-time.
2478: ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
2479: ** eligible to use [shared cache mode], regardless of whether or not shared
2480: ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
2481: ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2482: ** participate in [shared cache mode] even if it is enabled.
2483: **
2484: ** ^The fourth parameter to sqlite3_open_v2() is the name of the
2485: ** [sqlite3_vfs] object that defines the operating system interface that
2486: ** the new database connection should use. ^If the fourth parameter is
2487: ** a NULL pointer then the default [sqlite3_vfs] object is used.
2488: **
2489: ** ^If the filename is ":memory:", then a private, temporary in-memory database
2490: ** is created for the connection. ^This in-memory database will vanish when
2491: ** the database connection is closed. Future versions of SQLite might
2492: ** make use of additional special filenames that begin with the ":" character.
2493: ** It is recommended that when a database filename actually does begin with
2494: ** a ":" character you should prefix the filename with a pathname such as
2495: ** "./" to avoid ambiguity.
2496: **
2497: ** ^If the filename is an empty string, then a private, temporary
2498: ** on-disk database will be created. ^This private database will be
2499: ** automatically deleted as soon as the database connection is closed.
2500: **
2501: ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
2502: **
2503: ** ^If [URI filename] interpretation is enabled, and the filename argument
2504: ** begins with "file:", then the filename is interpreted as a URI. ^URI
2505: ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
2506: ** set in the fourth argument to sqlite3_open_v2(), or if it has
2507: ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
2508: ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
2509: ** As of SQLite version 3.7.7, URI filename interpretation is turned off
2510: ** by default, but future releases of SQLite might enable URI filename
2511: ** interpretation by default. See "[URI filenames]" for additional
2512: ** information.
2513: **
2514: ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
2515: ** authority, then it must be either an empty string or the string
2516: ** "localhost". ^If the authority is not an empty string or "localhost", an
2517: ** error is returned to the caller. ^The fragment component of a URI, if
2518: ** present, is ignored.
2519: **
2520: ** ^SQLite uses the path component of the URI as the name of the disk file
2521: ** which contains the database. ^If the path begins with a '/' character,
2522: ** then it is interpreted as an absolute path. ^If the path does not begin
2523: ** with a '/' (meaning that the authority section is omitted from the URI)
2524: ** then the path is interpreted as a relative path.
2525: ** ^On windows, the first component of an absolute path
2526: ** is a drive specification (e.g. "C:").
2527: **
2528: ** [[core URI query parameters]]
2529: ** The query component of a URI may contain parameters that are interpreted
2530: ** either by SQLite itself, or by a [VFS | custom VFS implementation].
2531: ** SQLite interprets the following three query parameters:
2532: **
2533: ** <ul>
2534: ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
2535: ** a VFS object that provides the operating system interface that should
2536: ** be used to access the database file on disk. ^If this option is set to
2537: ** an empty string the default VFS object is used. ^Specifying an unknown
2538: ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
2539: ** present, then the VFS specified by the option takes precedence over
2540: ** the value passed as the fourth parameter to sqlite3_open_v2().
2541: **
2542: ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or
2543: ** "rwc". Attempting to set it to any other value is an error)^.
2544: ** ^If "ro" is specified, then the database is opened for read-only
2545: ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
2546: ** third argument to sqlite3_prepare_v2(). ^If the mode option is set to
2547: ** "rw", then the database is opened for read-write (but not create)
2548: ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
2549: ** been set. ^Value "rwc" is equivalent to setting both
2550: ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is
2551: ** used, it is an error to specify a value for the mode parameter that is
2552: ** less restrictive than that specified by the flags passed as the third
2553: ** parameter.
2554: **
2555: ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
2556: ** "private". ^Setting it to "shared" is equivalent to setting the
2557: ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
2558: ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
2559: ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
2560: ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
2561: ** a URI filename, its value overrides any behaviour requested by setting
2562: ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
2563: ** </ul>
2564: **
2565: ** ^Specifying an unknown parameter in the query component of a URI is not an
2566: ** error. Future versions of SQLite might understand additional query
2567: ** parameters. See "[query parameters with special meaning to SQLite]" for
2568: ** additional information.
2569: **
2570: ** [[URI filename examples]] <h3>URI filename examples</h3>
2571: **
2572: ** <table border="1" align=center cellpadding=5>
2573: ** <tr><th> URI filenames <th> Results
2574: ** <tr><td> file:data.db <td>
2575: ** Open the file "data.db" in the current directory.
2576: ** <tr><td> file:/home/fred/data.db<br>
2577: ** file:///home/fred/data.db <br>
2578: ** file://localhost/home/fred/data.db <br> <td>
2579: ** Open the database file "/home/fred/data.db".
2580: ** <tr><td> file://darkstar/home/fred/data.db <td>
2581: ** An error. "darkstar" is not a recognized authority.
2582: ** <tr><td style="white-space:nowrap">
2583: ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
2584: ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
2585: ** C:. Note that the %20 escaping in this example is not strictly
2586: ** necessary - space characters can be used literally
2587: ** in URI filenames.
2588: ** <tr><td> file:data.db?mode=ro&cache=private <td>
2589: ** Open file "data.db" in the current directory for read-only access.
2590: ** Regardless of whether or not shared-cache mode is enabled by
2591: ** default, use a private cache.
2592: ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
2593: ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
2594: ** <tr><td> file:data.db?mode=readonly <td>
2595: ** An error. "readonly" is not a valid option for the "mode" parameter.
2596: ** </table>
2597: **
2598: ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
2599: ** query components of a URI. A hexadecimal escape sequence consists of a
2600: ** percent sign - "%" - followed by exactly two hexadecimal digits
2601: ** specifying an octet value. ^Before the path or query components of a
2602: ** URI filename are interpreted, they are encoded using UTF-8 and all
2603: ** hexadecimal escape sequences replaced by a single byte containing the
2604: ** corresponding octet. If this process generates an invalid UTF-8 encoding,
2605: ** the results are undefined.
2606: **
2607: ** <b>Note to Windows users:</b> The encoding used for the filename argument
2608: ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
2609: ** codepage is currently defined. Filenames containing international
2610: ** characters must be converted to UTF-8 prior to passing them into
2611: ** sqlite3_open() or sqlite3_open_v2().
2612: */
2613: SQLITE_API int sqlite3_open(
2614: const char *filename, /* Database filename (UTF-8) */
2615: sqlite3 **ppDb /* OUT: SQLite db handle */
2616: );
2617: SQLITE_API int sqlite3_open16(
2618: const void *filename, /* Database filename (UTF-16) */
2619: sqlite3 **ppDb /* OUT: SQLite db handle */
2620: );
2621: SQLITE_API int sqlite3_open_v2(
2622: const char *filename, /* Database filename (UTF-8) */
2623: sqlite3 **ppDb, /* OUT: SQLite db handle */
2624: int flags, /* Flags */
2625: const char *zVfs /* Name of VFS module to use */
2626: );
2627:
2628: /*
2629: ** CAPI3REF: Obtain Values For URI Parameters
2630: **
2631: ** These are utility routines, useful to VFS implementations, that check
2632: ** to see if a database file was a URI that contained a specific query
2633: ** parameter, and if so obtains the value of that query parameter.
2634: **
2635: ** If F is the database filename pointer passed into the xOpen() method of
2636: ** a VFS implementation when the flags parameter to xOpen() has one or
2637: ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
2638: ** P is the name of the query parameter, then
2639: ** sqlite3_uri_parameter(F,P) returns the value of the P
2640: ** parameter if it exists or a NULL pointer if P does not appear as a
2641: ** query parameter on F. If P is a query parameter of F
2642: ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
2643: ** a pointer to an empty string.
2644: **
2645: ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
2646: ** parameter and returns true (1) or false (0) according to the value
2647: ** of P. The value of P is true if it is "yes" or "true" or "on" or
2648: ** a non-zero number and is false otherwise. If P is not a query parameter
2649: ** on F then sqlite3_uri_boolean(F,P,B) returns (B!=0).
2650: **
2651: ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
2652: ** 64-bit signed integer and returns that integer, or D if P does not
2653: ** exist. If the value of P is something other than an integer, then
2654: ** zero is returned.
2655: **
2656: ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
2657: ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
2658: ** is not a database file pathname pointer that SQLite passed into the xOpen
2659: ** VFS method, then the behavior of this routine is undefined and probably
2660: ** undesirable.
2661: */
2662: SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
2663: SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
2664: SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
2665:
2666:
2667: /*
2668: ** CAPI3REF: Error Codes And Messages
2669: **
2670: ** ^The sqlite3_errcode() interface returns the numeric [result code] or
2671: ** [extended result code] for the most recent failed sqlite3_* API call
2672: ** associated with a [database connection]. If a prior API call failed
2673: ** but the most recent API call succeeded, the return value from
2674: ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode()
2675: ** interface is the same except that it always returns the
2676: ** [extended result code] even when extended result codes are
2677: ** disabled.
2678: **
2679: ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
2680: ** text that describes the error, as either UTF-8 or UTF-16 respectively.
2681: ** ^(Memory to hold the error message string is managed internally.
2682: ** The application does not need to worry about freeing the result.
2683: ** However, the error string might be overwritten or deallocated by
2684: ** subsequent calls to other SQLite interface functions.)^
2685: **
2686: ** When the serialized [threading mode] is in use, it might be the
2687: ** case that a second error occurs on a separate thread in between
2688: ** the time of the first error and the call to these interfaces.
2689: ** When that happens, the second error will be reported since these
2690: ** interfaces always report the most recent result. To avoid
2691: ** this, each thread can obtain exclusive use of the [database connection] D
2692: ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
2693: ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
2694: ** all calls to the interfaces listed here are completed.
2695: **
2696: ** If an interface fails with SQLITE_MISUSE, that means the interface
2697: ** was invoked incorrectly by the application. In that case, the
2698: ** error code and message may or may not be set.
2699: */
2700: SQLITE_API int sqlite3_errcode(sqlite3 *db);
2701: SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
2702: SQLITE_API const char *sqlite3_errmsg(sqlite3*);
2703: SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
2704:
2705: /*
2706: ** CAPI3REF: SQL Statement Object
2707: ** KEYWORDS: {prepared statement} {prepared statements}
2708: **
2709: ** An instance of this object represents a single SQL statement.
2710: ** This object is variously known as a "prepared statement" or a
2711: ** "compiled SQL statement" or simply as a "statement".
2712: **
2713: ** The life of a statement object goes something like this:
2714: **
2715: ** <ol>
2716: ** <li> Create the object using [sqlite3_prepare_v2()] or a related
2717: ** function.
2718: ** <li> Bind values to [host parameters] using the sqlite3_bind_*()
2719: ** interfaces.
2720: ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
2721: ** <li> Reset the statement using [sqlite3_reset()] then go back
2722: ** to step 2. Do this zero or more times.
2723: ** <li> Destroy the object using [sqlite3_finalize()].
2724: ** </ol>
2725: **
2726: ** Refer to documentation on individual methods above for additional
2727: ** information.
2728: */
2729: typedef struct sqlite3_stmt sqlite3_stmt;
2730:
2731: /*
2732: ** CAPI3REF: Run-time Limits
2733: **
2734: ** ^(This interface allows the size of various constructs to be limited
2735: ** on a connection by connection basis. The first parameter is the
2736: ** [database connection] whose limit is to be set or queried. The
2737: ** second parameter is one of the [limit categories] that define a
2738: ** class of constructs to be size limited. The third parameter is the
2739: ** new limit for that construct.)^
2740: **
2741: ** ^If the new limit is a negative number, the limit is unchanged.
2742: ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
2743: ** [limits | hard upper bound]
2744: ** set at compile-time by a C preprocessor macro called
2745: ** [limits | SQLITE_MAX_<i>NAME</i>].
2746: ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
2747: ** ^Attempts to increase a limit above its hard upper bound are
2748: ** silently truncated to the hard upper bound.
2749: **
2750: ** ^Regardless of whether or not the limit was changed, the
2751: ** [sqlite3_limit()] interface returns the prior value of the limit.
2752: ** ^Hence, to find the current value of a limit without changing it,
2753: ** simply invoke this interface with the third parameter set to -1.
2754: **
2755: ** Run-time limits are intended for use in applications that manage
2756: ** both their own internal database and also databases that are controlled
2757: ** by untrusted external sources. An example application might be a
2758: ** web browser that has its own databases for storing history and
2759: ** separate databases controlled by JavaScript applications downloaded
2760: ** off the Internet. The internal databases can be given the
2761: ** large, default limits. Databases managed by external sources can
2762: ** be given much smaller limits designed to prevent a denial of service
2763: ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
2764: ** interface to further control untrusted SQL. The size of the database
2765: ** created by an untrusted script can be contained using the
2766: ** [max_page_count] [PRAGMA].
2767: **
2768: ** New run-time limit categories may be added in future releases.
2769: */
2770: SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
2771:
2772: /*
2773: ** CAPI3REF: Run-Time Limit Categories
2774: ** KEYWORDS: {limit category} {*limit categories}
2775: **
2776: ** These constants define various performance limits
2777: ** that can be lowered at run-time using [sqlite3_limit()].
2778: ** The synopsis of the meanings of the various limits is shown below.
2779: ** Additional information is available at [limits | Limits in SQLite].
2780: **
2781: ** <dl>
2782: ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
2783: ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
2784: **
2785: ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
2786: ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
2787: **
2788: ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
2789: ** <dd>The maximum number of columns in a table definition or in the
2790: ** result set of a [SELECT] or the maximum number of columns in an index
2791: ** or in an ORDER BY or GROUP BY clause.</dd>)^
2792: **
2793: ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
2794: ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
2795: **
2796: ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
2797: ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
2798: **
2799: ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
2800: ** <dd>The maximum number of instructions in a virtual machine program
2801: ** used to implement an SQL statement. This limit is not currently
2802: ** enforced, though that might be added in some future release of
2803: ** SQLite.</dd>)^
2804: **
2805: ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
2806: ** <dd>The maximum number of arguments on a function.</dd>)^
2807: **
2808: ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
2809: ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
2810: **
2811: ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
2812: ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
2813: ** <dd>The maximum length of the pattern argument to the [LIKE] or
2814: ** [GLOB] operators.</dd>)^
2815: **
2816: ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
2817: ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
2818: ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
2819: **
2820: ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
2821: ** <dd>The maximum depth of recursion for triggers.</dd>)^
2822: ** </dl>
2823: */
2824: #define SQLITE_LIMIT_LENGTH 0
2825: #define SQLITE_LIMIT_SQL_LENGTH 1
2826: #define SQLITE_LIMIT_COLUMN 2
2827: #define SQLITE_LIMIT_EXPR_DEPTH 3
2828: #define SQLITE_LIMIT_COMPOUND_SELECT 4
2829: #define SQLITE_LIMIT_VDBE_OP 5
2830: #define SQLITE_LIMIT_FUNCTION_ARG 6
2831: #define SQLITE_LIMIT_ATTACHED 7
2832: #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
2833: #define SQLITE_LIMIT_VARIABLE_NUMBER 9
2834: #define SQLITE_LIMIT_TRIGGER_DEPTH 10
2835:
2836: /*
2837: ** CAPI3REF: Compiling An SQL Statement
2838: ** KEYWORDS: {SQL statement compiler}
2839: **
2840: ** To execute an SQL query, it must first be compiled into a byte-code
2841: ** program using one of these routines.
2842: **
2843: ** The first argument, "db", is a [database connection] obtained from a
2844: ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
2845: ** [sqlite3_open16()]. The database connection must not have been closed.
2846: **
2847: ** The second argument, "zSql", is the statement to be compiled, encoded
2848: ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
2849: ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
2850: ** use UTF-16.
2851: **
2852: ** ^If the nByte argument is less than zero, then zSql is read up to the
2853: ** first zero terminator. ^If nByte is non-negative, then it is the maximum
2854: ** number of bytes read from zSql. ^When nByte is non-negative, the
2855: ** zSql string ends at either the first '\000' or '\u0000' character or
2856: ** the nByte-th byte, whichever comes first. If the caller knows
2857: ** that the supplied string is nul-terminated, then there is a small
2858: ** performance advantage to be gained by passing an nByte parameter that
2859: ** is equal to the number of bytes in the input string <i>including</i>
2860: ** the nul-terminator bytes as this saves SQLite from having to
2861: ** make a copy of the input string.
2862: **
2863: ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
2864: ** past the end of the first SQL statement in zSql. These routines only
2865: ** compile the first statement in zSql, so *pzTail is left pointing to
2866: ** what remains uncompiled.
2867: **
2868: ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
2869: ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
2870: ** to NULL. ^If the input text contains no SQL (if the input is an empty
2871: ** string or a comment) then *ppStmt is set to NULL.
2872: ** The calling procedure is responsible for deleting the compiled
2873: ** SQL statement using [sqlite3_finalize()] after it has finished with it.
2874: ** ppStmt may not be NULL.
2875: **
2876: ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
2877: ** otherwise an [error code] is returned.
2878: **
2879: ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
2880: ** recommended for all new programs. The two older interfaces are retained
2881: ** for backwards compatibility, but their use is discouraged.
2882: ** ^In the "v2" interfaces, the prepared statement
2883: ** that is returned (the [sqlite3_stmt] object) contains a copy of the
2884: ** original SQL text. This causes the [sqlite3_step()] interface to
2885: ** behave differently in three ways:
2886: **
2887: ** <ol>
2888: ** <li>
2889: ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
2890: ** always used to do, [sqlite3_step()] will automatically recompile the SQL
2891: ** statement and try to run it again.
2892: ** </li>
2893: **
2894: ** <li>
2895: ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
2896: ** [error codes] or [extended error codes]. ^The legacy behavior was that
2897: ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
2898: ** and the application would have to make a second call to [sqlite3_reset()]
2899: ** in order to find the underlying cause of the problem. With the "v2" prepare
2900: ** interfaces, the underlying reason for the error is returned immediately.
2901: ** </li>
2902: **
2903: ** <li>
2904: ** ^If the specific value bound to [parameter | host parameter] in the
2905: ** WHERE clause might influence the choice of query plan for a statement,
2906: ** then the statement will be automatically recompiled, as if there had been
2907: ** a schema change, on the first [sqlite3_step()] call following any change
2908: ** to the [sqlite3_bind_text | bindings] of that [parameter].
2909: ** ^The specific value of WHERE-clause [parameter] might influence the
2910: ** choice of query plan if the parameter is the left-hand side of a [LIKE]
2911: ** or [GLOB] operator or if the parameter is compared to an indexed column
2912: ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
2913: ** the
2914: ** </li>
2915: ** </ol>
2916: */
2917: SQLITE_API int sqlite3_prepare(
2918: sqlite3 *db, /* Database handle */
2919: const char *zSql, /* SQL statement, UTF-8 encoded */
2920: int nByte, /* Maximum length of zSql in bytes. */
2921: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2922: const char **pzTail /* OUT: Pointer to unused portion of zSql */
2923: );
2924: SQLITE_API int sqlite3_prepare_v2(
2925: sqlite3 *db, /* Database handle */
2926: const char *zSql, /* SQL statement, UTF-8 encoded */
2927: int nByte, /* Maximum length of zSql in bytes. */
2928: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2929: const char **pzTail /* OUT: Pointer to unused portion of zSql */
2930: );
2931: SQLITE_API int sqlite3_prepare16(
2932: sqlite3 *db, /* Database handle */
2933: const void *zSql, /* SQL statement, UTF-16 encoded */
2934: int nByte, /* Maximum length of zSql in bytes. */
2935: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2936: const void **pzTail /* OUT: Pointer to unused portion of zSql */
2937: );
2938: SQLITE_API int sqlite3_prepare16_v2(
2939: sqlite3 *db, /* Database handle */
2940: const void *zSql, /* SQL statement, UTF-16 encoded */
2941: int nByte, /* Maximum length of zSql in bytes. */
2942: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2943: const void **pzTail /* OUT: Pointer to unused portion of zSql */
2944: );
2945:
2946: /*
2947: ** CAPI3REF: Retrieving Statement SQL
2948: **
2949: ** ^This interface can be used to retrieve a saved copy of the original
2950: ** SQL text used to create a [prepared statement] if that statement was
2951: ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
2952: */
2953: SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
2954:
2955: /*
2956: ** CAPI3REF: Determine If An SQL Statement Writes The Database
2957: **
2958: ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
2959: ** and only if the [prepared statement] X makes no direct changes to
2960: ** the content of the database file.
2961: **
2962: ** Note that [application-defined SQL functions] or
2963: ** [virtual tables] might change the database indirectly as a side effect.
2964: ** ^(For example, if an application defines a function "eval()" that
2965: ** calls [sqlite3_exec()], then the following SQL statement would
2966: ** change the database file through side-effects:
2967: **
2968: ** <blockquote><pre>
2969: ** SELECT eval('DELETE FROM t1') FROM t2;
2970: ** </pre></blockquote>
2971: **
2972: ** But because the [SELECT] statement does not change the database file
2973: ** directly, sqlite3_stmt_readonly() would still return true.)^
2974: **
2975: ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
2976: ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
2977: ** since the statements themselves do not actually modify the database but
2978: ** rather they control the timing of when other statements modify the
2979: ** database. ^The [ATTACH] and [DETACH] statements also cause
2980: ** sqlite3_stmt_readonly() to return true since, while those statements
2981: ** change the configuration of a database connection, they do not make
2982: ** changes to the content of the database files on disk.
2983: */
2984: SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
2985:
2986: /*
2987: ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
2988: **
2989: ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
2990: ** [prepared statement] S has been stepped at least once using
2991: ** [sqlite3_step(S)] but has not run to completion and/or has not
2992: ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
2993: ** interface returns false if S is a NULL pointer. If S is not a
2994: ** NULL pointer and is not a pointer to a valid [prepared statement]
2995: ** object, then the behavior is undefined and probably undesirable.
2996: **
2997: ** This interface can be used in combination [sqlite3_next_stmt()]
2998: ** to locate all prepared statements associated with a database
2999: ** connection that are in need of being reset. This can be used,
3000: ** for example, in diagnostic routines to search for prepared
3001: ** statements that are holding a transaction open.
3002: */
3003: SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3004:
3005: /*
3006: ** CAPI3REF: Dynamically Typed Value Object
3007: ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3008: **
3009: ** SQLite uses the sqlite3_value object to represent all values
3010: ** that can be stored in a database table. SQLite uses dynamic typing
3011: ** for the values it stores. ^Values stored in sqlite3_value objects
3012: ** can be integers, floating point values, strings, BLOBs, or NULL.
3013: **
3014: ** An sqlite3_value object may be either "protected" or "unprotected".
3015: ** Some interfaces require a protected sqlite3_value. Other interfaces
3016: ** will accept either a protected or an unprotected sqlite3_value.
3017: ** Every interface that accepts sqlite3_value arguments specifies
3018: ** whether or not it requires a protected sqlite3_value.
3019: **
3020: ** The terms "protected" and "unprotected" refer to whether or not
3021: ** a mutex is held. An internal mutex is held for a protected
3022: ** sqlite3_value object but no mutex is held for an unprotected
3023: ** sqlite3_value object. If SQLite is compiled to be single-threaded
3024: ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3025: ** or if SQLite is run in one of reduced mutex modes
3026: ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3027: ** then there is no distinction between protected and unprotected
3028: ** sqlite3_value objects and they can be used interchangeably. However,
3029: ** for maximum code portability it is recommended that applications
3030: ** still make the distinction between protected and unprotected
3031: ** sqlite3_value objects even when not strictly required.
3032: **
3033: ** ^The sqlite3_value objects that are passed as parameters into the
3034: ** implementation of [application-defined SQL functions] are protected.
3035: ** ^The sqlite3_value object returned by
3036: ** [sqlite3_column_value()] is unprotected.
3037: ** Unprotected sqlite3_value objects may only be used with
3038: ** [sqlite3_result_value()] and [sqlite3_bind_value()].
3039: ** The [sqlite3_value_blob | sqlite3_value_type()] family of
3040: ** interfaces require protected sqlite3_value objects.
3041: */
3042: typedef struct Mem sqlite3_value;
3043:
3044: /*
3045: ** CAPI3REF: SQL Function Context Object
3046: **
3047: ** The context in which an SQL function executes is stored in an
3048: ** sqlite3_context object. ^A pointer to an sqlite3_context object
3049: ** is always first parameter to [application-defined SQL functions].
3050: ** The application-defined SQL function implementation will pass this
3051: ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3052: ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3053: ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3054: ** and/or [sqlite3_set_auxdata()].
3055: */
3056: typedef struct sqlite3_context sqlite3_context;
3057:
3058: /*
3059: ** CAPI3REF: Binding Values To Prepared Statements
3060: ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3061: ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3062: **
3063: ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3064: ** literals may be replaced by a [parameter] that matches one of following
3065: ** templates:
3066: **
3067: ** <ul>
3068: ** <li> ?
3069: ** <li> ?NNN
3070: ** <li> :VVV
3071: ** <li> @VVV
3072: ** <li> $VVV
3073: ** </ul>
3074: **
3075: ** In the templates above, NNN represents an integer literal,
3076: ** and VVV represents an alphanumeric identifier.)^ ^The values of these
3077: ** parameters (also called "host parameter names" or "SQL parameters")
3078: ** can be set using the sqlite3_bind_*() routines defined here.
3079: **
3080: ** ^The first argument to the sqlite3_bind_*() routines is always
3081: ** a pointer to the [sqlite3_stmt] object returned from
3082: ** [sqlite3_prepare_v2()] or its variants.
3083: **
3084: ** ^The second argument is the index of the SQL parameter to be set.
3085: ** ^The leftmost SQL parameter has an index of 1. ^When the same named
3086: ** SQL parameter is used more than once, second and subsequent
3087: ** occurrences have the same index as the first occurrence.
3088: ** ^The index for named parameters can be looked up using the
3089: ** [sqlite3_bind_parameter_index()] API if desired. ^The index
3090: ** for "?NNN" parameters is the value of NNN.
3091: ** ^The NNN value must be between 1 and the [sqlite3_limit()]
3092: ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3093: **
3094: ** ^The third argument is the value to bind to the parameter.
3095: **
3096: ** ^(In those routines that have a fourth argument, its value is the
3097: ** number of bytes in the parameter. To be clear: the value is the
3098: ** number of <u>bytes</u> in the value, not the number of characters.)^
3099: ** ^If the fourth parameter is negative, the length of the string is
3100: ** the number of bytes up to the first zero terminator.
3101: ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3102: ** or sqlite3_bind_text16() then that parameter must be the byte offset
3103: ** where the NUL terminator would occur assuming the string were NUL
3104: ** terminated. If any NUL characters occur at byte offsets less than
3105: ** the value of the fourth parameter then the resulting string value will
3106: ** contain embedded NULs. The result of expressions involving strings
3107: ** with embedded NULs is undefined.
3108: **
3109: ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
3110: ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
3111: ** string after SQLite has finished with it. ^The destructor is called
3112: ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
3113: ** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
3114: ** ^If the fifth argument is
3115: ** the special value [SQLITE_STATIC], then SQLite assumes that the
3116: ** information is in static, unmanaged space and does not need to be freed.
3117: ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3118: ** SQLite makes its own private copy of the data immediately, before
3119: ** the sqlite3_bind_*() routine returns.
3120: **
3121: ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3122: ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
3123: ** (just an integer to hold its size) while it is being processed.
3124: ** Zeroblobs are intended to serve as placeholders for BLOBs whose
3125: ** content is later written using
3126: ** [sqlite3_blob_open | incremental BLOB I/O] routines.
3127: ** ^A negative value for the zeroblob results in a zero-length BLOB.
3128: **
3129: ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3130: ** for the [prepared statement] or with a prepared statement for which
3131: ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3132: ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
3133: ** routine is passed a [prepared statement] that has been finalized, the
3134: ** result is undefined and probably harmful.
3135: **
3136: ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3137: ** ^Unbound parameters are interpreted as NULL.
3138: **
3139: ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3140: ** [error code] if anything goes wrong.
3141: ** ^[SQLITE_RANGE] is returned if the parameter
3142: ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
3143: **
3144: ** See also: [sqlite3_bind_parameter_count()],
3145: ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3146: */
3147: SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3148: SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3149: SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3150: SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3151: SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
3152: SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
3153: SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3154: SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3155: SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3156:
3157: /*
3158: ** CAPI3REF: Number Of SQL Parameters
3159: **
3160: ** ^This routine can be used to find the number of [SQL parameters]
3161: ** in a [prepared statement]. SQL parameters are tokens of the
3162: ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3163: ** placeholders for values that are [sqlite3_bind_blob | bound]
3164: ** to the parameters at a later time.
3165: **
3166: ** ^(This routine actually returns the index of the largest (rightmost)
3167: ** parameter. For all forms except ?NNN, this will correspond to the
3168: ** number of unique parameters. If parameters of the ?NNN form are used,
3169: ** there may be gaps in the list.)^
3170: **
3171: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3172: ** [sqlite3_bind_parameter_name()], and
3173: ** [sqlite3_bind_parameter_index()].
3174: */
3175: SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
3176:
3177: /*
3178: ** CAPI3REF: Name Of A Host Parameter
3179: **
3180: ** ^The sqlite3_bind_parameter_name(P,N) interface returns
3181: ** the name of the N-th [SQL parameter] in the [prepared statement] P.
3182: ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3183: ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3184: ** respectively.
3185: ** In other words, the initial ":" or "$" or "@" or "?"
3186: ** is included as part of the name.)^
3187: ** ^Parameters of the form "?" without a following integer have no name
3188: ** and are referred to as "nameless" or "anonymous parameters".
3189: **
3190: ** ^The first host parameter has an index of 1, not 0.
3191: **
3192: ** ^If the value N is out of range or if the N-th parameter is
3193: ** nameless, then NULL is returned. ^The returned string is
3194: ** always in UTF-8 encoding even if the named parameter was
3195: ** originally specified as UTF-16 in [sqlite3_prepare16()] or
3196: ** [sqlite3_prepare16_v2()].
3197: **
3198: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3199: ** [sqlite3_bind_parameter_count()], and
3200: ** [sqlite3_bind_parameter_index()].
3201: */
3202: SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3203:
3204: /*
3205: ** CAPI3REF: Index Of A Parameter With A Given Name
3206: **
3207: ** ^Return the index of an SQL parameter given its name. ^The
3208: ** index value returned is suitable for use as the second
3209: ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
3210: ** is returned if no matching parameter is found. ^The parameter
3211: ** name must be given in UTF-8 even if the original statement
3212: ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3213: **
3214: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3215: ** [sqlite3_bind_parameter_count()], and
3216: ** [sqlite3_bind_parameter_index()].
3217: */
3218: SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3219:
3220: /*
3221: ** CAPI3REF: Reset All Bindings On A Prepared Statement
3222: **
3223: ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3224: ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3225: ** ^Use this routine to reset all host parameters to NULL.
3226: */
3227: SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
3228:
3229: /*
3230: ** CAPI3REF: Number Of Columns In A Result Set
3231: **
3232: ** ^Return the number of columns in the result set returned by the
3233: ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3234: ** statement that does not return data (for example an [UPDATE]).
3235: **
3236: ** See also: [sqlite3_data_count()]
3237: */
3238: SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
3239:
3240: /*
3241: ** CAPI3REF: Column Names In A Result Set
3242: **
3243: ** ^These routines return the name assigned to a particular column
3244: ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
3245: ** interface returns a pointer to a zero-terminated UTF-8 string
3246: ** and sqlite3_column_name16() returns a pointer to a zero-terminated
3247: ** UTF-16 string. ^The first parameter is the [prepared statement]
3248: ** that implements the [SELECT] statement. ^The second parameter is the
3249: ** column number. ^The leftmost column is number 0.
3250: **
3251: ** ^The returned string pointer is valid until either the [prepared statement]
3252: ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3253: ** reprepared by the first call to [sqlite3_step()] for a particular run
3254: ** or until the next call to
3255: ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3256: **
3257: ** ^If sqlite3_malloc() fails during the processing of either routine
3258: ** (for example during a conversion from UTF-8 to UTF-16) then a
3259: ** NULL pointer is returned.
3260: **
3261: ** ^The name of a result column is the value of the "AS" clause for
3262: ** that column, if there is an AS clause. If there is no AS clause
3263: ** then the name of the column is unspecified and may change from
3264: ** one release of SQLite to the next.
3265: */
3266: SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
3267: SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3268:
3269: /*
3270: ** CAPI3REF: Source Of Data In A Query Result
3271: **
3272: ** ^These routines provide a means to determine the database, table, and
3273: ** table column that is the origin of a particular result column in
3274: ** [SELECT] statement.
3275: ** ^The name of the database or table or column can be returned as
3276: ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
3277: ** the database name, the _table_ routines return the table name, and
3278: ** the origin_ routines return the column name.
3279: ** ^The returned string is valid until the [prepared statement] is destroyed
3280: ** using [sqlite3_finalize()] or until the statement is automatically
3281: ** reprepared by the first call to [sqlite3_step()] for a particular run
3282: ** or until the same information is requested
3283: ** again in a different encoding.
3284: **
3285: ** ^The names returned are the original un-aliased names of the
3286: ** database, table, and column.
3287: **
3288: ** ^The first argument to these interfaces is a [prepared statement].
3289: ** ^These functions return information about the Nth result column returned by
3290: ** the statement, where N is the second function argument.
3291: ** ^The left-most column is column 0 for these routines.
3292: **
3293: ** ^If the Nth column returned by the statement is an expression or
3294: ** subquery and is not a column value, then all of these functions return
3295: ** NULL. ^These routine might also return NULL if a memory allocation error
3296: ** occurs. ^Otherwise, they return the name of the attached database, table,
3297: ** or column that query result column was extracted from.
3298: **
3299: ** ^As with all other SQLite APIs, those whose names end with "16" return
3300: ** UTF-16 encoded strings and the other functions return UTF-8.
3301: **
3302: ** ^These APIs are only available if the library was compiled with the
3303: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3304: **
3305: ** If two or more threads call one or more of these routines against the same
3306: ** prepared statement and column at the same time then the results are
3307: ** undefined.
3308: **
3309: ** If two or more threads call one or more
3310: ** [sqlite3_column_database_name | column metadata interfaces]
3311: ** for the same [prepared statement] and result column
3312: ** at the same time then the results are undefined.
3313: */
3314: SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
3315: SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
3316: SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
3317: SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
3318: SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
3319: SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
3320:
3321: /*
3322: ** CAPI3REF: Declared Datatype Of A Query Result
3323: **
3324: ** ^(The first parameter is a [prepared statement].
3325: ** If this statement is a [SELECT] statement and the Nth column of the
3326: ** returned result set of that [SELECT] is a table column (not an
3327: ** expression or subquery) then the declared type of the table
3328: ** column is returned.)^ ^If the Nth column of the result set is an
3329: ** expression or subquery, then a NULL pointer is returned.
3330: ** ^The returned string is always UTF-8 encoded.
3331: **
3332: ** ^(For example, given the database schema:
3333: **
3334: ** CREATE TABLE t1(c1 VARIANT);
3335: **
3336: ** and the following statement to be compiled:
3337: **
3338: ** SELECT c1 + 1, c1 FROM t1;
3339: **
3340: ** this routine would return the string "VARIANT" for the second result
3341: ** column (i==1), and a NULL pointer for the first result column (i==0).)^
3342: **
3343: ** ^SQLite uses dynamic run-time typing. ^So just because a column
3344: ** is declared to contain a particular type does not mean that the
3345: ** data stored in that column is of the declared type. SQLite is
3346: ** strongly typed, but the typing is dynamic not static. ^Type
3347: ** is associated with individual values, not with the containers
3348: ** used to hold those values.
3349: */
3350: SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
3351: SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
3352:
3353: /*
3354: ** CAPI3REF: Evaluate An SQL Statement
3355: **
3356: ** After a [prepared statement] has been prepared using either
3357: ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3358: ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3359: ** must be called one or more times to evaluate the statement.
3360: **
3361: ** The details of the behavior of the sqlite3_step() interface depend
3362: ** on whether the statement was prepared using the newer "v2" interface
3363: ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3364: ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
3365: ** new "v2" interface is recommended for new applications but the legacy
3366: ** interface will continue to be supported.
3367: **
3368: ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
3369: ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
3370: ** ^With the "v2" interface, any of the other [result codes] or
3371: ** [extended result codes] might be returned as well.
3372: **
3373: ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
3374: ** database locks it needs to do its job. ^If the statement is a [COMMIT]
3375: ** or occurs outside of an explicit transaction, then you can retry the
3376: ** statement. If the statement is not a [COMMIT] and occurs within an
3377: ** explicit transaction then you should rollback the transaction before
3378: ** continuing.
3379: **
3380: ** ^[SQLITE_DONE] means that the statement has finished executing
3381: ** successfully. sqlite3_step() should not be called again on this virtual
3382: ** machine without first calling [sqlite3_reset()] to reset the virtual
3383: ** machine back to its initial state.
3384: **
3385: ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
3386: ** is returned each time a new row of data is ready for processing by the
3387: ** caller. The values may be accessed using the [column access functions].
3388: ** sqlite3_step() is called again to retrieve the next row of data.
3389: **
3390: ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
3391: ** violation) has occurred. sqlite3_step() should not be called again on
3392: ** the VM. More information may be found by calling [sqlite3_errmsg()].
3393: ** ^With the legacy interface, a more specific error code (for example,
3394: ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
3395: ** can be obtained by calling [sqlite3_reset()] on the
3396: ** [prepared statement]. ^In the "v2" interface,
3397: ** the more specific error code is returned directly by sqlite3_step().
3398: **
3399: ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3400: ** Perhaps it was called on a [prepared statement] that has
3401: ** already been [sqlite3_finalize | finalized] or on one that had
3402: ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
3403: ** be the case that the same database connection is being used by two or
3404: ** more threads at the same moment in time.
3405: **
3406: ** For all versions of SQLite up to and including 3.6.23.1, a call to
3407: ** [sqlite3_reset()] was required after sqlite3_step() returned anything
3408: ** other than [SQLITE_ROW] before any subsequent invocation of
3409: ** sqlite3_step(). Failure to reset the prepared statement using
3410: ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
3411: ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began
3412: ** calling [sqlite3_reset()] automatically in this circumstance rather
3413: ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
3414: ** break because any application that ever receives an SQLITE_MISUSE error
3415: ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
3416: ** can be used to restore the legacy behavior.
3417: **
3418: ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3419: ** API always returns a generic error code, [SQLITE_ERROR], following any
3420: ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
3421: ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3422: ** specific [error codes] that better describes the error.
3423: ** We admit that this is a goofy design. The problem has been fixed
3424: ** with the "v2" interface. If you prepare all of your SQL statements
3425: ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3426: ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3427: ** then the more specific [error codes] are returned directly
3428: ** by sqlite3_step(). The use of the "v2" interface is recommended.
3429: */
3430: SQLITE_API int sqlite3_step(sqlite3_stmt*);
3431:
3432: /*
3433: ** CAPI3REF: Number of columns in a result set
3434: **
3435: ** ^The sqlite3_data_count(P) interface returns the number of columns in the
3436: ** current row of the result set of [prepared statement] P.
3437: ** ^If prepared statement P does not have results ready to return
3438: ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
3439: ** interfaces) then sqlite3_data_count(P) returns 0.
3440: ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
3441: ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
3442: ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
3443: ** will return non-zero if previous call to [sqlite3_step](P) returned
3444: ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
3445: ** where it always returns zero since each step of that multi-step
3446: ** pragma returns 0 columns of data.
3447: **
3448: ** See also: [sqlite3_column_count()]
3449: */
3450: SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
3451:
3452: /*
3453: ** CAPI3REF: Fundamental Datatypes
3454: ** KEYWORDS: SQLITE_TEXT
3455: **
3456: ** ^(Every value in SQLite has one of five fundamental datatypes:
3457: **
3458: ** <ul>
3459: ** <li> 64-bit signed integer
3460: ** <li> 64-bit IEEE floating point number
3461: ** <li> string
3462: ** <li> BLOB
3463: ** <li> NULL
3464: ** </ul>)^
3465: **
3466: ** These constants are codes for each of those types.
3467: **
3468: ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3469: ** for a completely different meaning. Software that links against both
3470: ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3471: ** SQLITE_TEXT.
3472: */
3473: #define SQLITE_INTEGER 1
3474: #define SQLITE_FLOAT 2
3475: #define SQLITE_BLOB 4
3476: #define SQLITE_NULL 5
3477: #ifdef SQLITE_TEXT
3478: # undef SQLITE_TEXT
3479: #else
3480: # define SQLITE_TEXT 3
3481: #endif
3482: #define SQLITE3_TEXT 3
3483:
3484: /*
3485: ** CAPI3REF: Result Values From A Query
3486: ** KEYWORDS: {column access functions}
3487: **
3488: ** These routines form the "result set" interface.
3489: **
3490: ** ^These routines return information about a single column of the current
3491: ** result row of a query. ^In every case the first argument is a pointer
3492: ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3493: ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3494: ** and the second argument is the index of the column for which information
3495: ** should be returned. ^The leftmost column of the result set has the index 0.
3496: ** ^The number of columns in the result can be determined using
3497: ** [sqlite3_column_count()].
3498: **
3499: ** If the SQL statement does not currently point to a valid row, or if the
3500: ** column index is out of range, the result is undefined.
3501: ** These routines may only be called when the most recent call to
3502: ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3503: ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3504: ** If any of these routines are called after [sqlite3_reset()] or
3505: ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3506: ** something other than [SQLITE_ROW], the results are undefined.
3507: ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
3508: ** are called from a different thread while any of these routines
3509: ** are pending, then the results are undefined.
3510: **
3511: ** ^The sqlite3_column_type() routine returns the
3512: ** [SQLITE_INTEGER | datatype code] for the initial data type
3513: ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
3514: ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
3515: ** returned by sqlite3_column_type() is only meaningful if no type
3516: ** conversions have occurred as described below. After a type conversion,
3517: ** the value returned by sqlite3_column_type() is undefined. Future
3518: ** versions of SQLite may change the behavior of sqlite3_column_type()
3519: ** following a type conversion.
3520: **
3521: ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
3522: ** routine returns the number of bytes in that BLOB or string.
3523: ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
3524: ** the string to UTF-8 and then returns the number of bytes.
3525: ** ^If the result is a numeric value then sqlite3_column_bytes() uses
3526: ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
3527: ** the number of bytes in that string.
3528: ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
3529: **
3530: ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
3531: ** routine returns the number of bytes in that BLOB or string.
3532: ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
3533: ** the string to UTF-16 and then returns the number of bytes.
3534: ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
3535: ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
3536: ** the number of bytes in that string.
3537: ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
3538: **
3539: ** ^The values returned by [sqlite3_column_bytes()] and
3540: ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
3541: ** of the string. ^For clarity: the values returned by
3542: ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
3543: ** bytes in the string, not the number of characters.
3544: **
3545: ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
3546: ** even empty strings, are always zero-terminated. ^The return
3547: ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
3548: **
3549: ** ^The object returned by [sqlite3_column_value()] is an
3550: ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
3551: ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
3552: ** If the [unprotected sqlite3_value] object returned by
3553: ** [sqlite3_column_value()] is used in any other way, including calls
3554: ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
3555: ** or [sqlite3_value_bytes()], then the behavior is undefined.
3556: **
3557: ** These routines attempt to convert the value where appropriate. ^For
3558: ** example, if the internal representation is FLOAT and a text result
3559: ** is requested, [sqlite3_snprintf()] is used internally to perform the
3560: ** conversion automatically. ^(The following table details the conversions
3561: ** that are applied:
3562: **
3563: ** <blockquote>
3564: ** <table border="1">
3565: ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
3566: **
3567: ** <tr><td> NULL <td> INTEGER <td> Result is 0
3568: ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
3569: ** <tr><td> NULL <td> TEXT <td> Result is NULL pointer
3570: ** <tr><td> NULL <td> BLOB <td> Result is NULL pointer
3571: ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
3572: ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
3573: ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
3574: ** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer
3575: ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
3576: ** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT
3577: ** <tr><td> TEXT <td> INTEGER <td> Use atoi()
3578: ** <tr><td> TEXT <td> FLOAT <td> Use atof()
3579: ** <tr><td> TEXT <td> BLOB <td> No change
3580: ** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi()
3581: ** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof()
3582: ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
3583: ** </table>
3584: ** </blockquote>)^
3585: **
3586: ** The table above makes reference to standard C library functions atoi()
3587: ** and atof(). SQLite does not really use these functions. It has its
3588: ** own equivalent internal routines. The atoi() and atof() names are
3589: ** used in the table for brevity and because they are familiar to most
3590: ** C programmers.
3591: **
3592: ** Note that when type conversions occur, pointers returned by prior
3593: ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
3594: ** sqlite3_column_text16() may be invalidated.
3595: ** Type conversions and pointer invalidations might occur
3596: ** in the following cases:
3597: **
3598: ** <ul>
3599: ** <li> The initial content is a BLOB and sqlite3_column_text() or
3600: ** sqlite3_column_text16() is called. A zero-terminator might
3601: ** need to be added to the string.</li>
3602: ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
3603: ** sqlite3_column_text16() is called. The content must be converted
3604: ** to UTF-16.</li>
3605: ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
3606: ** sqlite3_column_text() is called. The content must be converted
3607: ** to UTF-8.</li>
3608: ** </ul>
3609: **
3610: ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
3611: ** not invalidate a prior pointer, though of course the content of the buffer
3612: ** that the prior pointer references will have been modified. Other kinds
3613: ** of conversion are done in place when it is possible, but sometimes they
3614: ** are not possible and in those cases prior pointers are invalidated.
3615: **
3616: ** The safest and easiest to remember policy is to invoke these routines
3617: ** in one of the following ways:
3618: **
3619: ** <ul>
3620: ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
3621: ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
3622: ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
3623: ** </ul>
3624: **
3625: ** In other words, you should call sqlite3_column_text(),
3626: ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
3627: ** into the desired format, then invoke sqlite3_column_bytes() or
3628: ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
3629: ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
3630: ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
3631: ** with calls to sqlite3_column_bytes().
3632: **
3633: ** ^The pointers returned are valid until a type conversion occurs as
3634: ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
3635: ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
3636: ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned
3637: ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
3638: ** [sqlite3_free()].
3639: **
3640: ** ^(If a memory allocation error occurs during the evaluation of any
3641: ** of these routines, a default value is returned. The default value
3642: ** is either the integer 0, the floating point number 0.0, or a NULL
3643: ** pointer. Subsequent calls to [sqlite3_errcode()] will return
3644: ** [SQLITE_NOMEM].)^
3645: */
3646: SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
3647: SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
3648: SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
3649: SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
3650: SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
3651: SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
3652: SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
3653: SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
3654: SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
3655: SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
3656:
3657: /*
3658: ** CAPI3REF: Destroy A Prepared Statement Object
3659: **
3660: ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
3661: ** ^If the most recent evaluation of the statement encountered no errors
3662: ** or if the statement is never been evaluated, then sqlite3_finalize() returns
3663: ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
3664: ** sqlite3_finalize(S) returns the appropriate [error code] or
3665: ** [extended error code].
3666: **
3667: ** ^The sqlite3_finalize(S) routine can be called at any point during
3668: ** the life cycle of [prepared statement] S:
3669: ** before statement S is ever evaluated, after
3670: ** one or more calls to [sqlite3_reset()], or after any call
3671: ** to [sqlite3_step()] regardless of whether or not the statement has
3672: ** completed execution.
3673: **
3674: ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
3675: **
3676: ** The application must finalize every [prepared statement] in order to avoid
3677: ** resource leaks. It is a grievous error for the application to try to use
3678: ** a prepared statement after it has been finalized. Any use of a prepared
3679: ** statement after it has been finalized can result in undefined and
3680: ** undesirable behavior such as segfaults and heap corruption.
3681: */
3682: SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
3683:
3684: /*
3685: ** CAPI3REF: Reset A Prepared Statement Object
3686: **
3687: ** The sqlite3_reset() function is called to reset a [prepared statement]
3688: ** object back to its initial state, ready to be re-executed.
3689: ** ^Any SQL statement variables that had values bound to them using
3690: ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
3691: ** Use [sqlite3_clear_bindings()] to reset the bindings.
3692: **
3693: ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
3694: ** back to the beginning of its program.
3695: **
3696: ** ^If the most recent call to [sqlite3_step(S)] for the
3697: ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
3698: ** or if [sqlite3_step(S)] has never before been called on S,
3699: ** then [sqlite3_reset(S)] returns [SQLITE_OK].
3700: **
3701: ** ^If the most recent call to [sqlite3_step(S)] for the
3702: ** [prepared statement] S indicated an error, then
3703: ** [sqlite3_reset(S)] returns an appropriate [error code].
3704: **
3705: ** ^The [sqlite3_reset(S)] interface does not change the values
3706: ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
3707: */
3708: SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
3709:
3710: /*
3711: ** CAPI3REF: Create Or Redefine SQL Functions
3712: ** KEYWORDS: {function creation routines}
3713: ** KEYWORDS: {application-defined SQL function}
3714: ** KEYWORDS: {application-defined SQL functions}
3715: **
3716: ** ^These functions (collectively known as "function creation routines")
3717: ** are used to add SQL functions or aggregates or to redefine the behavior
3718: ** of existing SQL functions or aggregates. The only differences between
3719: ** these routines are the text encoding expected for
3720: ** the second parameter (the name of the function being created)
3721: ** and the presence or absence of a destructor callback for
3722: ** the application data pointer.
3723: **
3724: ** ^The first parameter is the [database connection] to which the SQL
3725: ** function is to be added. ^If an application uses more than one database
3726: ** connection then application-defined SQL functions must be added
3727: ** to each database connection separately.
3728: **
3729: ** ^The second parameter is the name of the SQL function to be created or
3730: ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
3731: ** representation, exclusive of the zero-terminator. ^Note that the name
3732: ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
3733: ** ^Any attempt to create a function with a longer name
3734: ** will result in [SQLITE_MISUSE] being returned.
3735: **
3736: ** ^The third parameter (nArg)
3737: ** is the number of arguments that the SQL function or
3738: ** aggregate takes. ^If this parameter is -1, then the SQL function or
3739: ** aggregate may take any number of arguments between 0 and the limit
3740: ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
3741: ** parameter is less than -1 or greater than 127 then the behavior is
3742: ** undefined.
3743: **
3744: ** ^The fourth parameter, eTextRep, specifies what
3745: ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
3746: ** its parameters. Every SQL function implementation must be able to work
3747: ** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
3748: ** more efficient with one encoding than another. ^An application may
3749: ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
3750: ** times with the same function but with different values of eTextRep.
3751: ** ^When multiple implementations of the same function are available, SQLite
3752: ** will pick the one that involves the least amount of data conversion.
3753: ** If there is only a single implementation which does not care what text
3754: ** encoding is used, then the fourth argument should be [SQLITE_ANY].
3755: **
3756: ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
3757: ** function can gain access to this pointer using [sqlite3_user_data()].)^
3758: **
3759: ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
3760: ** pointers to C-language functions that implement the SQL function or
3761: ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
3762: ** callback only; NULL pointers must be passed as the xStep and xFinal
3763: ** parameters. ^An aggregate SQL function requires an implementation of xStep
3764: ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
3765: ** SQL function or aggregate, pass NULL pointers for all three function
3766: ** callbacks.
3767: **
3768: ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
3769: ** then it is destructor for the application data pointer.
3770: ** The destructor is invoked when the function is deleted, either by being
3771: ** overloaded or when the database connection closes.)^
3772: ** ^The destructor is also invoked if the call to
3773: ** sqlite3_create_function_v2() fails.
3774: ** ^When the destructor callback of the tenth parameter is invoked, it
3775: ** is passed a single argument which is a copy of the application data
3776: ** pointer which was the fifth parameter to sqlite3_create_function_v2().
3777: **
3778: ** ^It is permitted to register multiple implementations of the same
3779: ** functions with the same name but with either differing numbers of
3780: ** arguments or differing preferred text encodings. ^SQLite will use
3781: ** the implementation that most closely matches the way in which the
3782: ** SQL function is used. ^A function implementation with a non-negative
3783: ** nArg parameter is a better match than a function implementation with
3784: ** a negative nArg. ^A function where the preferred text encoding
3785: ** matches the database encoding is a better
3786: ** match than a function where the encoding is different.
3787: ** ^A function where the encoding difference is between UTF16le and UTF16be
3788: ** is a closer match than a function where the encoding difference is
3789: ** between UTF8 and UTF16.
3790: **
3791: ** ^Built-in functions may be overloaded by new application-defined functions.
3792: **
3793: ** ^An application-defined function is permitted to call other
3794: ** SQLite interfaces. However, such calls must not
3795: ** close the database connection nor finalize or reset the prepared
3796: ** statement in which the function is running.
3797: */
3798: SQLITE_API int sqlite3_create_function(
3799: sqlite3 *db,
3800: const char *zFunctionName,
3801: int nArg,
3802: int eTextRep,
3803: void *pApp,
3804: void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3805: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3806: void (*xFinal)(sqlite3_context*)
3807: );
3808: SQLITE_API int sqlite3_create_function16(
3809: sqlite3 *db,
3810: const void *zFunctionName,
3811: int nArg,
3812: int eTextRep,
3813: void *pApp,
3814: void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3815: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3816: void (*xFinal)(sqlite3_context*)
3817: );
3818: SQLITE_API int sqlite3_create_function_v2(
3819: sqlite3 *db,
3820: const char *zFunctionName,
3821: int nArg,
3822: int eTextRep,
3823: void *pApp,
3824: void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3825: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3826: void (*xFinal)(sqlite3_context*),
3827: void(*xDestroy)(void*)
3828: );
3829:
3830: /*
3831: ** CAPI3REF: Text Encodings
3832: **
3833: ** These constant define integer codes that represent the various
3834: ** text encodings supported by SQLite.
3835: */
3836: #define SQLITE_UTF8 1
3837: #define SQLITE_UTF16LE 2
3838: #define SQLITE_UTF16BE 3
3839: #define SQLITE_UTF16 4 /* Use native byte order */
3840: #define SQLITE_ANY 5 /* sqlite3_create_function only */
3841: #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
3842:
3843: /*
3844: ** CAPI3REF: Deprecated Functions
3845: ** DEPRECATED
3846: **
3847: ** These functions are [deprecated]. In order to maintain
3848: ** backwards compatibility with older code, these functions continue
3849: ** to be supported. However, new applications should avoid
3850: ** the use of these functions. To help encourage people to avoid
3851: ** using these functions, we are not going to tell you what they do.
3852: */
3853: #ifndef SQLITE_OMIT_DEPRECATED
3854: SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
3855: SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
3856: SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
3857: SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
3858: SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
3859: SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
3860: #endif
3861:
3862: /*
3863: ** CAPI3REF: Obtaining SQL Function Parameter Values
3864: **
3865: ** The C-language implementation of SQL functions and aggregates uses
3866: ** this set of interface routines to access the parameter values on
3867: ** the function or aggregate.
3868: **
3869: ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
3870: ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
3871: ** define callbacks that implement the SQL functions and aggregates.
3872: ** The 3rd parameter to these callbacks is an array of pointers to
3873: ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
3874: ** each parameter to the SQL function. These routines are used to
3875: ** extract values from the [sqlite3_value] objects.
3876: **
3877: ** These routines work only with [protected sqlite3_value] objects.
3878: ** Any attempt to use these routines on an [unprotected sqlite3_value]
3879: ** object results in undefined behavior.
3880: **
3881: ** ^These routines work just like the corresponding [column access functions]
3882: ** except that these routines take a single [protected sqlite3_value] object
3883: ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
3884: **
3885: ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
3886: ** in the native byte-order of the host machine. ^The
3887: ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
3888: ** extract UTF-16 strings as big-endian and little-endian respectively.
3889: **
3890: ** ^(The sqlite3_value_numeric_type() interface attempts to apply
3891: ** numeric affinity to the value. This means that an attempt is
3892: ** made to convert the value to an integer or floating point. If
3893: ** such a conversion is possible without loss of information (in other
3894: ** words, if the value is a string that looks like a number)
3895: ** then the conversion is performed. Otherwise no conversion occurs.
3896: ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
3897: **
3898: ** Please pay particular attention to the fact that the pointer returned
3899: ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
3900: ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
3901: ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
3902: ** or [sqlite3_value_text16()].
3903: **
3904: ** These routines must be called from the same thread as
3905: ** the SQL function that supplied the [sqlite3_value*] parameters.
3906: */
3907: SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
3908: SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
3909: SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
3910: SQLITE_API double sqlite3_value_double(sqlite3_value*);
3911: SQLITE_API int sqlite3_value_int(sqlite3_value*);
3912: SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
3913: SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
3914: SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
3915: SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
3916: SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
3917: SQLITE_API int sqlite3_value_type(sqlite3_value*);
3918: SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
3919:
3920: /*
3921: ** CAPI3REF: Obtain Aggregate Function Context
3922: **
3923: ** Implementations of aggregate SQL functions use this
3924: ** routine to allocate memory for storing their state.
3925: **
3926: ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
3927: ** for a particular aggregate function, SQLite
3928: ** allocates N of memory, zeroes out that memory, and returns a pointer
3929: ** to the new memory. ^On second and subsequent calls to
3930: ** sqlite3_aggregate_context() for the same aggregate function instance,
3931: ** the same buffer is returned. Sqlite3_aggregate_context() is normally
3932: ** called once for each invocation of the xStep callback and then one
3933: ** last time when the xFinal callback is invoked. ^(When no rows match
3934: ** an aggregate query, the xStep() callback of the aggregate function
3935: ** implementation is never called and xFinal() is called exactly once.
3936: ** In those cases, sqlite3_aggregate_context() might be called for the
3937: ** first time from within xFinal().)^
3938: **
3939: ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
3940: ** less than or equal to zero or if a memory allocate error occurs.
3941: **
3942: ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
3943: ** determined by the N parameter on first successful call. Changing the
3944: ** value of N in subsequent call to sqlite3_aggregate_context() within
3945: ** the same aggregate function instance will not resize the memory
3946: ** allocation.)^
3947: **
3948: ** ^SQLite automatically frees the memory allocated by
3949: ** sqlite3_aggregate_context() when the aggregate query concludes.
3950: **
3951: ** The first parameter must be a copy of the
3952: ** [sqlite3_context | SQL function context] that is the first parameter
3953: ** to the xStep or xFinal callback routine that implements the aggregate
3954: ** function.
3955: **
3956: ** This routine must be called from the same thread in which
3957: ** the aggregate SQL function is running.
3958: */
3959: SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
3960:
3961: /*
3962: ** CAPI3REF: User Data For Functions
3963: **
3964: ** ^The sqlite3_user_data() interface returns a copy of
3965: ** the pointer that was the pUserData parameter (the 5th parameter)
3966: ** of the [sqlite3_create_function()]
3967: ** and [sqlite3_create_function16()] routines that originally
3968: ** registered the application defined function.
3969: **
3970: ** This routine must be called from the same thread in which
3971: ** the application-defined function is running.
3972: */
3973: SQLITE_API void *sqlite3_user_data(sqlite3_context*);
3974:
3975: /*
3976: ** CAPI3REF: Database Connection For Functions
3977: **
3978: ** ^The sqlite3_context_db_handle() interface returns a copy of
3979: ** the pointer to the [database connection] (the 1st parameter)
3980: ** of the [sqlite3_create_function()]
3981: ** and [sqlite3_create_function16()] routines that originally
3982: ** registered the application defined function.
3983: */
3984: SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
3985:
3986: /*
3987: ** CAPI3REF: Function Auxiliary Data
3988: **
3989: ** The following two functions may be used by scalar SQL functions to
3990: ** associate metadata with argument values. If the same value is passed to
3991: ** multiple invocations of the same SQL function during query execution, under
3992: ** some circumstances the associated metadata may be preserved. This may
3993: ** be used, for example, to add a regular-expression matching scalar
3994: ** function. The compiled version of the regular expression is stored as
3995: ** metadata associated with the SQL value passed as the regular expression
3996: ** pattern. The compiled regular expression can be reused on multiple
3997: ** invocations of the same function so that the original pattern string
3998: ** does not need to be recompiled on each invocation.
3999: **
4000: ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4001: ** associated by the sqlite3_set_auxdata() function with the Nth argument
4002: ** value to the application-defined function. ^If no metadata has been ever
4003: ** been set for the Nth argument of the function, or if the corresponding
4004: ** function parameter has changed since the meta-data was set,
4005: ** then sqlite3_get_auxdata() returns a NULL pointer.
4006: **
4007: ** ^The sqlite3_set_auxdata() interface saves the metadata
4008: ** pointed to by its 3rd parameter as the metadata for the N-th
4009: ** argument of the application-defined function. Subsequent
4010: ** calls to sqlite3_get_auxdata() might return this data, if it has
4011: ** not been destroyed.
4012: ** ^If it is not NULL, SQLite will invoke the destructor
4013: ** function given by the 4th parameter to sqlite3_set_auxdata() on
4014: ** the metadata when the corresponding function parameter changes
4015: ** or when the SQL statement completes, whichever comes first.
4016: **
4017: ** SQLite is free to call the destructor and drop metadata on any
4018: ** parameter of any function at any time. ^The only guarantee is that
4019: ** the destructor will be called before the metadata is dropped.
4020: **
4021: ** ^(In practice, metadata is preserved between function calls for
4022: ** expressions that are constant at compile time. This includes literal
4023: ** values and [parameters].)^
4024: **
4025: ** These routines must be called from the same thread in which
4026: ** the SQL function is running.
4027: */
4028: SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
4029: SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4030:
4031:
4032: /*
4033: ** CAPI3REF: Constants Defining Special Destructor Behavior
4034: **
4035: ** These are special values for the destructor that is passed in as the
4036: ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
4037: ** argument is SQLITE_STATIC, it means that the content pointer is constant
4038: ** and will never change. It does not need to be destroyed. ^The
4039: ** SQLITE_TRANSIENT value means that the content will likely change in
4040: ** the near future and that SQLite should make its own private copy of
4041: ** the content before returning.
4042: **
4043: ** The typedef is necessary to work around problems in certain
4044: ** C++ compilers. See ticket #2191.
4045: */
4046: typedef void (*sqlite3_destructor_type)(void*);
4047: #define SQLITE_STATIC ((sqlite3_destructor_type)0)
4048: #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
4049:
4050: /*
4051: ** CAPI3REF: Setting The Result Of An SQL Function
4052: **
4053: ** These routines are used by the xFunc or xFinal callbacks that
4054: ** implement SQL functions and aggregates. See
4055: ** [sqlite3_create_function()] and [sqlite3_create_function16()]
4056: ** for additional information.
4057: **
4058: ** These functions work very much like the [parameter binding] family of
4059: ** functions used to bind values to host parameters in prepared statements.
4060: ** Refer to the [SQL parameter] documentation for additional information.
4061: **
4062: ** ^The sqlite3_result_blob() interface sets the result from
4063: ** an application-defined function to be the BLOB whose content is pointed
4064: ** to by the second parameter and which is N bytes long where N is the
4065: ** third parameter.
4066: **
4067: ** ^The sqlite3_result_zeroblob() interfaces set the result of
4068: ** the application-defined function to be a BLOB containing all zero
4069: ** bytes and N bytes in size, where N is the value of the 2nd parameter.
4070: **
4071: ** ^The sqlite3_result_double() interface sets the result from
4072: ** an application-defined function to be a floating point value specified
4073: ** by its 2nd argument.
4074: **
4075: ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4076: ** cause the implemented SQL function to throw an exception.
4077: ** ^SQLite uses the string pointed to by the
4078: ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4079: ** as the text of an error message. ^SQLite interprets the error
4080: ** message string from sqlite3_result_error() as UTF-8. ^SQLite
4081: ** interprets the string from sqlite3_result_error16() as UTF-16 in native
4082: ** byte order. ^If the third parameter to sqlite3_result_error()
4083: ** or sqlite3_result_error16() is negative then SQLite takes as the error
4084: ** message all text up through the first zero character.
4085: ** ^If the third parameter to sqlite3_result_error() or
4086: ** sqlite3_result_error16() is non-negative then SQLite takes that many
4087: ** bytes (not characters) from the 2nd parameter as the error message.
4088: ** ^The sqlite3_result_error() and sqlite3_result_error16()
4089: ** routines make a private copy of the error message text before
4090: ** they return. Hence, the calling function can deallocate or
4091: ** modify the text after they return without harm.
4092: ** ^The sqlite3_result_error_code() function changes the error code
4093: ** returned by SQLite as a result of an error in a function. ^By default,
4094: ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
4095: ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4096: **
4097: ** ^The sqlite3_result_toobig() interface causes SQLite to throw an error
4098: ** indicating that a string or BLOB is too long to represent.
4099: **
4100: ** ^The sqlite3_result_nomem() interface causes SQLite to throw an error
4101: ** indicating that a memory allocation failed.
4102: **
4103: ** ^The sqlite3_result_int() interface sets the return value
4104: ** of the application-defined function to be the 32-bit signed integer
4105: ** value given in the 2nd argument.
4106: ** ^The sqlite3_result_int64() interface sets the return value
4107: ** of the application-defined function to be the 64-bit signed integer
4108: ** value given in the 2nd argument.
4109: **
4110: ** ^The sqlite3_result_null() interface sets the return value
4111: ** of the application-defined function to be NULL.
4112: **
4113: ** ^The sqlite3_result_text(), sqlite3_result_text16(),
4114: ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4115: ** set the return value of the application-defined function to be
4116: ** a text string which is represented as UTF-8, UTF-16 native byte order,
4117: ** UTF-16 little endian, or UTF-16 big endian, respectively.
4118: ** ^SQLite takes the text result from the application from
4119: ** the 2nd parameter of the sqlite3_result_text* interfaces.
4120: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4121: ** is negative, then SQLite takes result text from the 2nd parameter
4122: ** through the first zero character.
4123: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4124: ** is non-negative, then as many bytes (not characters) of the text
4125: ** pointed to by the 2nd parameter are taken as the application-defined
4126: ** function result. If the 3rd parameter is non-negative, then it
4127: ** must be the byte offset into the string where the NUL terminator would
4128: ** appear if the string where NUL terminated. If any NUL characters occur
4129: ** in the string at a byte offset that is less than the value of the 3rd
4130: ** parameter, then the resulting string will contain embedded NULs and the
4131: ** result of expressions operating on strings with embedded NULs is undefined.
4132: ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4133: ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4134: ** function as the destructor on the text or BLOB result when it has
4135: ** finished using that result.
4136: ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4137: ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4138: ** assumes that the text or BLOB result is in constant space and does not
4139: ** copy the content of the parameter nor call a destructor on the content
4140: ** when it has finished using that result.
4141: ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4142: ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4143: ** then SQLite makes a copy of the result into space obtained from
4144: ** from [sqlite3_malloc()] before it returns.
4145: **
4146: ** ^The sqlite3_result_value() interface sets the result of
4147: ** the application-defined function to be a copy the
4148: ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
4149: ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4150: ** so that the [sqlite3_value] specified in the parameter may change or
4151: ** be deallocated after sqlite3_result_value() returns without harm.
4152: ** ^A [protected sqlite3_value] object may always be used where an
4153: ** [unprotected sqlite3_value] object is required, so either
4154: ** kind of [sqlite3_value] object can be used with this interface.
4155: **
4156: ** If these routines are called from within the different thread
4157: ** than the one containing the application-defined function that received
4158: ** the [sqlite3_context] pointer, the results are undefined.
4159: */
4160: SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4161: SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
4162: SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
4163: SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
4164: SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
4165: SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
4166: SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
4167: SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
4168: SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4169: SQLITE_API void sqlite3_result_null(sqlite3_context*);
4170: SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4171: SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4172: SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4173: SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4174: SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4175: SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
4176:
4177: /*
4178: ** CAPI3REF: Define New Collating Sequences
4179: **
4180: ** ^These functions add, remove, or modify a [collation] associated
4181: ** with the [database connection] specified as the first argument.
4182: **
4183: ** ^The name of the collation is a UTF-8 string
4184: ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4185: ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4186: ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4187: ** considered to be the same name.
4188: **
4189: ** ^(The third argument (eTextRep) must be one of the constants:
4190: ** <ul>
4191: ** <li> [SQLITE_UTF8],
4192: ** <li> [SQLITE_UTF16LE],
4193: ** <li> [SQLITE_UTF16BE],
4194: ** <li> [SQLITE_UTF16], or
4195: ** <li> [SQLITE_UTF16_ALIGNED].
4196: ** </ul>)^
4197: ** ^The eTextRep argument determines the encoding of strings passed
4198: ** to the collating function callback, xCallback.
4199: ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4200: ** force strings to be UTF16 with native byte order.
4201: ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4202: ** on an even byte address.
4203: **
4204: ** ^The fourth argument, pArg, is an application data pointer that is passed
4205: ** through as the first argument to the collating function callback.
4206: **
4207: ** ^The fifth argument, xCallback, is a pointer to the collating function.
4208: ** ^Multiple collating functions can be registered using the same name but
4209: ** with different eTextRep parameters and SQLite will use whichever
4210: ** function requires the least amount of data transformation.
4211: ** ^If the xCallback argument is NULL then the collating function is
4212: ** deleted. ^When all collating functions having the same name are deleted,
4213: ** that collation is no longer usable.
4214: **
4215: ** ^The collating function callback is invoked with a copy of the pArg
4216: ** application data pointer and with two strings in the encoding specified
4217: ** by the eTextRep argument. The collating function must return an
4218: ** integer that is negative, zero, or positive
4219: ** if the first string is less than, equal to, or greater than the second,
4220: ** respectively. A collating function must always return the same answer
4221: ** given the same inputs. If two or more collating functions are registered
4222: ** to the same collation name (using different eTextRep values) then all
4223: ** must give an equivalent answer when invoked with equivalent strings.
4224: ** The collating function must obey the following properties for all
4225: ** strings A, B, and C:
4226: **
4227: ** <ol>
4228: ** <li> If A==B then B==A.
4229: ** <li> If A==B and B==C then A==C.
4230: ** <li> If A<B THEN B>A.
4231: ** <li> If A<B and B<C then A<C.
4232: ** </ol>
4233: **
4234: ** If a collating function fails any of the above constraints and that
4235: ** collating function is registered and used, then the behavior of SQLite
4236: ** is undefined.
4237: **
4238: ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4239: ** with the addition that the xDestroy callback is invoked on pArg when
4240: ** the collating function is deleted.
4241: ** ^Collating functions are deleted when they are overridden by later
4242: ** calls to the collation creation functions or when the
4243: ** [database connection] is closed using [sqlite3_close()].
4244: **
4245: ** ^The xDestroy callback is <u>not</u> called if the
4246: ** sqlite3_create_collation_v2() function fails. Applications that invoke
4247: ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
4248: ** check the return code and dispose of the application data pointer
4249: ** themselves rather than expecting SQLite to deal with it for them.
4250: ** This is different from every other SQLite interface. The inconsistency
4251: ** is unfortunate but cannot be changed without breaking backwards
4252: ** compatibility.
4253: **
4254: ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4255: */
4256: SQLITE_API int sqlite3_create_collation(
4257: sqlite3*,
4258: const char *zName,
4259: int eTextRep,
4260: void *pArg,
4261: int(*xCompare)(void*,int,const void*,int,const void*)
4262: );
4263: SQLITE_API int sqlite3_create_collation_v2(
4264: sqlite3*,
4265: const char *zName,
4266: int eTextRep,
4267: void *pArg,
4268: int(*xCompare)(void*,int,const void*,int,const void*),
4269: void(*xDestroy)(void*)
4270: );
4271: SQLITE_API int sqlite3_create_collation16(
4272: sqlite3*,
4273: const void *zName,
4274: int eTextRep,
4275: void *pArg,
4276: int(*xCompare)(void*,int,const void*,int,const void*)
4277: );
4278:
4279: /*
4280: ** CAPI3REF: Collation Needed Callbacks
4281: **
4282: ** ^To avoid having to register all collation sequences before a database
4283: ** can be used, a single callback function may be registered with the
4284: ** [database connection] to be invoked whenever an undefined collation
4285: ** sequence is required.
4286: **
4287: ** ^If the function is registered using the sqlite3_collation_needed() API,
4288: ** then it is passed the names of undefined collation sequences as strings
4289: ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
4290: ** the names are passed as UTF-16 in machine native byte order.
4291: ** ^A call to either function replaces the existing collation-needed callback.
4292: **
4293: ** ^(When the callback is invoked, the first argument passed is a copy
4294: ** of the second argument to sqlite3_collation_needed() or
4295: ** sqlite3_collation_needed16(). The second argument is the database
4296: ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4297: ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4298: ** sequence function required. The fourth parameter is the name of the
4299: ** required collation sequence.)^
4300: **
4301: ** The callback function should register the desired collation using
4302: ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4303: ** [sqlite3_create_collation_v2()].
4304: */
4305: SQLITE_API int sqlite3_collation_needed(
4306: sqlite3*,
4307: void*,
4308: void(*)(void*,sqlite3*,int eTextRep,const char*)
4309: );
4310: SQLITE_API int sqlite3_collation_needed16(
4311: sqlite3*,
4312: void*,
4313: void(*)(void*,sqlite3*,int eTextRep,const void*)
4314: );
4315:
4316: #ifdef SQLITE_HAS_CODEC
4317: /*
4318: ** Specify the key for an encrypted database. This routine should be
4319: ** called right after sqlite3_open().
4320: **
4321: ** The code to implement this API is not available in the public release
4322: ** of SQLite.
4323: */
4324: SQLITE_API int sqlite3_key(
4325: sqlite3 *db, /* Database to be rekeyed */
4326: const void *pKey, int nKey /* The key */
4327: );
4328:
4329: /*
4330: ** Change the key on an open database. If the current database is not
4331: ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
4332: ** database is decrypted.
4333: **
4334: ** The code to implement this API is not available in the public release
4335: ** of SQLite.
4336: */
4337: SQLITE_API int sqlite3_rekey(
4338: sqlite3 *db, /* Database to be rekeyed */
4339: const void *pKey, int nKey /* The new key */
4340: );
4341:
4342: /*
4343: ** Specify the activation key for a SEE database. Unless
4344: ** activated, none of the SEE routines will work.
4345: */
4346: SQLITE_API void sqlite3_activate_see(
4347: const char *zPassPhrase /* Activation phrase */
4348: );
4349: #endif
4350:
4351: #ifdef SQLITE_ENABLE_CEROD
4352: /*
4353: ** Specify the activation key for a CEROD database. Unless
4354: ** activated, none of the CEROD routines will work.
4355: */
4356: SQLITE_API void sqlite3_activate_cerod(
4357: const char *zPassPhrase /* Activation phrase */
4358: );
4359: #endif
4360:
4361: /*
4362: ** CAPI3REF: Suspend Execution For A Short Time
4363: **
4364: ** The sqlite3_sleep() function causes the current thread to suspend execution
4365: ** for at least a number of milliseconds specified in its parameter.
4366: **
4367: ** If the operating system does not support sleep requests with
4368: ** millisecond time resolution, then the time will be rounded up to
4369: ** the nearest second. The number of milliseconds of sleep actually
4370: ** requested from the operating system is returned.
4371: **
4372: ** ^SQLite implements this interface by calling the xSleep()
4373: ** method of the default [sqlite3_vfs] object. If the xSleep() method
4374: ** of the default VFS is not implemented correctly, or not implemented at
4375: ** all, then the behavior of sqlite3_sleep() may deviate from the description
4376: ** in the previous paragraphs.
4377: */
4378: SQLITE_API int sqlite3_sleep(int);
4379:
4380: /*
4381: ** CAPI3REF: Name Of The Folder Holding Temporary Files
4382: **
4383: ** ^(If this global variable is made to point to a string which is
4384: ** the name of a folder (a.k.a. directory), then all temporary files
4385: ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
4386: ** will be placed in that directory.)^ ^If this variable
4387: ** is a NULL pointer, then SQLite performs a search for an appropriate
4388: ** temporary file directory.
4389: **
4390: ** It is not safe to read or modify this variable in more than one
4391: ** thread at a time. It is not safe to read or modify this variable
4392: ** if a [database connection] is being used at the same time in a separate
4393: ** thread.
4394: ** It is intended that this variable be set once
4395: ** as part of process initialization and before any SQLite interface
4396: ** routines have been called and that this variable remain unchanged
4397: ** thereafter.
4398: **
4399: ** ^The [temp_store_directory pragma] may modify this variable and cause
4400: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
4401: ** the [temp_store_directory pragma] always assumes that any string
4402: ** that this variable points to is held in memory obtained from
4403: ** [sqlite3_malloc] and the pragma may attempt to free that memory
4404: ** using [sqlite3_free].
4405: ** Hence, if this variable is modified directly, either it should be
4406: ** made NULL or made to point to memory obtained from [sqlite3_malloc]
4407: ** or else the use of the [temp_store_directory pragma] should be avoided.
4408: */
4409: SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
4410:
4411: /*
4412: ** CAPI3REF: Test For Auto-Commit Mode
4413: ** KEYWORDS: {autocommit mode}
4414: **
4415: ** ^The sqlite3_get_autocommit() interface returns non-zero or
4416: ** zero if the given database connection is or is not in autocommit mode,
4417: ** respectively. ^Autocommit mode is on by default.
4418: ** ^Autocommit mode is disabled by a [BEGIN] statement.
4419: ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
4420: **
4421: ** If certain kinds of errors occur on a statement within a multi-statement
4422: ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
4423: ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
4424: ** transaction might be rolled back automatically. The only way to
4425: ** find out whether SQLite automatically rolled back the transaction after
4426: ** an error is to use this function.
4427: **
4428: ** If another thread changes the autocommit status of the database
4429: ** connection while this routine is running, then the return value
4430: ** is undefined.
4431: */
4432: SQLITE_API int sqlite3_get_autocommit(sqlite3*);
4433:
4434: /*
4435: ** CAPI3REF: Find The Database Handle Of A Prepared Statement
4436: **
4437: ** ^The sqlite3_db_handle interface returns the [database connection] handle
4438: ** to which a [prepared statement] belongs. ^The [database connection]
4439: ** returned by sqlite3_db_handle is the same [database connection]
4440: ** that was the first argument
4441: ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
4442: ** create the statement in the first place.
4443: */
4444: SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
4445:
4446: /*
4447: ** CAPI3REF: Return The Filename For A Database Connection
4448: **
4449: ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
4450: ** associated with database N of connection D. ^The main database file
4451: ** has the name "main". If there is no attached database N on the database
4452: ** connection D, or if database N is a temporary or in-memory database, then
4453: ** a NULL pointer is returned.
4454: **
4455: ** ^The filename returned by this function is the output of the
4456: ** xFullPathname method of the [VFS]. ^In other words, the filename
4457: ** will be an absolute pathname, even if the filename used
4458: ** to open the database originally was a URI or relative pathname.
4459: */
4460: SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
4461:
4462: /*
4463: ** CAPI3REF: Find the next prepared statement
4464: **
4465: ** ^This interface returns a pointer to the next [prepared statement] after
4466: ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
4467: ** then this interface returns a pointer to the first prepared statement
4468: ** associated with the database connection pDb. ^If no prepared statement
4469: ** satisfies the conditions of this routine, it returns NULL.
4470: **
4471: ** The [database connection] pointer D in a call to
4472: ** [sqlite3_next_stmt(D,S)] must refer to an open database
4473: ** connection and in particular must not be a NULL pointer.
4474: */
4475: SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
4476:
4477: /*
4478: ** CAPI3REF: Commit And Rollback Notification Callbacks
4479: **
4480: ** ^The sqlite3_commit_hook() interface registers a callback
4481: ** function to be invoked whenever a transaction is [COMMIT | committed].
4482: ** ^Any callback set by a previous call to sqlite3_commit_hook()
4483: ** for the same database connection is overridden.
4484: ** ^The sqlite3_rollback_hook() interface registers a callback
4485: ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
4486: ** ^Any callback set by a previous call to sqlite3_rollback_hook()
4487: ** for the same database connection is overridden.
4488: ** ^The pArg argument is passed through to the callback.
4489: ** ^If the callback on a commit hook function returns non-zero,
4490: ** then the commit is converted into a rollback.
4491: **
4492: ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
4493: ** return the P argument from the previous call of the same function
4494: ** on the same [database connection] D, or NULL for
4495: ** the first call for each function on D.
4496: **
4497: ** The commit and rollback hook callbacks are not reentrant.
4498: ** The callback implementation must not do anything that will modify
4499: ** the database connection that invoked the callback. Any actions
4500: ** to modify the database connection must be deferred until after the
4501: ** completion of the [sqlite3_step()] call that triggered the commit
4502: ** or rollback hook in the first place.
4503: ** Note that running any other SQL statements, including SELECT statements,
4504: ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
4505: ** the database connections for the meaning of "modify" in this paragraph.
4506: **
4507: ** ^Registering a NULL function disables the callback.
4508: **
4509: ** ^When the commit hook callback routine returns zero, the [COMMIT]
4510: ** operation is allowed to continue normally. ^If the commit hook
4511: ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
4512: ** ^The rollback hook is invoked on a rollback that results from a commit
4513: ** hook returning non-zero, just as it would be with any other rollback.
4514: **
4515: ** ^For the purposes of this API, a transaction is said to have been
4516: ** rolled back if an explicit "ROLLBACK" statement is executed, or
4517: ** an error or constraint causes an implicit rollback to occur.
4518: ** ^The rollback callback is not invoked if a transaction is
4519: ** automatically rolled back because the database connection is closed.
4520: **
4521: ** See also the [sqlite3_update_hook()] interface.
4522: */
4523: SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
4524: SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
4525:
4526: /*
4527: ** CAPI3REF: Data Change Notification Callbacks
4528: **
4529: ** ^The sqlite3_update_hook() interface registers a callback function
4530: ** with the [database connection] identified by the first argument
4531: ** to be invoked whenever a row is updated, inserted or deleted.
4532: ** ^Any callback set by a previous call to this function
4533: ** for the same database connection is overridden.
4534: **
4535: ** ^The second argument is a pointer to the function to invoke when a
4536: ** row is updated, inserted or deleted.
4537: ** ^The first argument to the callback is a copy of the third argument
4538: ** to sqlite3_update_hook().
4539: ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
4540: ** or [SQLITE_UPDATE], depending on the operation that caused the callback
4541: ** to be invoked.
4542: ** ^The third and fourth arguments to the callback contain pointers to the
4543: ** database and table name containing the affected row.
4544: ** ^The final callback parameter is the [rowid] of the row.
4545: ** ^In the case of an update, this is the [rowid] after the update takes place.
4546: **
4547: ** ^(The update hook is not invoked when internal system tables are
4548: ** modified (i.e. sqlite_master and sqlite_sequence).)^
4549: **
4550: ** ^In the current implementation, the update hook
4551: ** is not invoked when duplication rows are deleted because of an
4552: ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
4553: ** invoked when rows are deleted using the [truncate optimization].
4554: ** The exceptions defined in this paragraph might change in a future
4555: ** release of SQLite.
4556: **
4557: ** The update hook implementation must not do anything that will modify
4558: ** the database connection that invoked the update hook. Any actions
4559: ** to modify the database connection must be deferred until after the
4560: ** completion of the [sqlite3_step()] call that triggered the update hook.
4561: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
4562: ** database connections for the meaning of "modify" in this paragraph.
4563: **
4564: ** ^The sqlite3_update_hook(D,C,P) function
4565: ** returns the P argument from the previous call
4566: ** on the same [database connection] D, or NULL for
4567: ** the first call on D.
4568: **
4569: ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
4570: ** interfaces.
4571: */
4572: SQLITE_API void *sqlite3_update_hook(
4573: sqlite3*,
4574: void(*)(void *,int ,char const *,char const *,sqlite3_int64),
4575: void*
4576: );
4577:
4578: /*
4579: ** CAPI3REF: Enable Or Disable Shared Pager Cache
4580: ** KEYWORDS: {shared cache}
4581: **
4582: ** ^(This routine enables or disables the sharing of the database cache
4583: ** and schema data structures between [database connection | connections]
4584: ** to the same database. Sharing is enabled if the argument is true
4585: ** and disabled if the argument is false.)^
4586: **
4587: ** ^Cache sharing is enabled and disabled for an entire process.
4588: ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
4589: ** sharing was enabled or disabled for each thread separately.
4590: **
4591: ** ^(The cache sharing mode set by this interface effects all subsequent
4592: ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
4593: ** Existing database connections continue use the sharing mode
4594: ** that was in effect at the time they were opened.)^
4595: **
4596: ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
4597: ** successfully. An [error code] is returned otherwise.)^
4598: **
4599: ** ^Shared cache is disabled by default. But this might change in
4600: ** future releases of SQLite. Applications that care about shared
4601: ** cache setting should set it explicitly.
4602: **
4603: ** See Also: [SQLite Shared-Cache Mode]
4604: */
4605: SQLITE_API int sqlite3_enable_shared_cache(int);
4606:
4607: /*
4608: ** CAPI3REF: Attempt To Free Heap Memory
4609: **
4610: ** ^The sqlite3_release_memory() interface attempts to free N bytes
4611: ** of heap memory by deallocating non-essential memory allocations
4612: ** held by the database library. Memory used to cache database
4613: ** pages to improve performance is an example of non-essential memory.
4614: ** ^sqlite3_release_memory() returns the number of bytes actually freed,
4615: ** which might be more or less than the amount requested.
4616: ** ^The sqlite3_release_memory() routine is a no-op returning zero
4617: ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
4618: **
4619: ** See also: [sqlite3_db_release_memory()]
4620: */
4621: SQLITE_API int sqlite3_release_memory(int);
4622:
4623: /*
4624: ** CAPI3REF: Free Memory Used By A Database Connection
4625: **
4626: ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
4627: ** memory as possible from database connection D. Unlike the
4628: ** [sqlite3_release_memory()] interface, this interface is effect even
4629: ** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
4630: ** omitted.
4631: **
4632: ** See also: [sqlite3_release_memory()]
4633: */
4634: SQLITE_API int sqlite3_db_release_memory(sqlite3*);
4635:
4636: /*
4637: ** CAPI3REF: Impose A Limit On Heap Size
4638: **
4639: ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
4640: ** soft limit on the amount of heap memory that may be allocated by SQLite.
4641: ** ^SQLite strives to keep heap memory utilization below the soft heap
4642: ** limit by reducing the number of pages held in the page cache
4643: ** as heap memory usages approaches the limit.
4644: ** ^The soft heap limit is "soft" because even though SQLite strives to stay
4645: ** below the limit, it will exceed the limit rather than generate
4646: ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
4647: ** is advisory only.
4648: **
4649: ** ^The return value from sqlite3_soft_heap_limit64() is the size of
4650: ** the soft heap limit prior to the call, or negative in the case of an
4651: ** error. ^If the argument N is negative
4652: ** then no change is made to the soft heap limit. Hence, the current
4653: ** size of the soft heap limit can be determined by invoking
4654: ** sqlite3_soft_heap_limit64() with a negative argument.
4655: **
4656: ** ^If the argument N is zero then the soft heap limit is disabled.
4657: **
4658: ** ^(The soft heap limit is not enforced in the current implementation
4659: ** if one or more of following conditions are true:
4660: **
4661: ** <ul>
4662: ** <li> The soft heap limit is set to zero.
4663: ** <li> Memory accounting is disabled using a combination of the
4664: ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
4665: ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
4666: ** <li> An alternative page cache implementation is specified using
4667: ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
4668: ** <li> The page cache allocates from its own memory pool supplied
4669: ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
4670: ** from the heap.
4671: ** </ul>)^
4672: **
4673: ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
4674: ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
4675: ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
4676: ** the soft heap limit is enforced on every memory allocation. Without
4677: ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
4678: ** when memory is allocated by the page cache. Testing suggests that because
4679: ** the page cache is the predominate memory user in SQLite, most
4680: ** applications will achieve adequate soft heap limit enforcement without
4681: ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
4682: **
4683: ** The circumstances under which SQLite will enforce the soft heap limit may
4684: ** changes in future releases of SQLite.
4685: */
4686: SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
4687:
4688: /*
4689: ** CAPI3REF: Deprecated Soft Heap Limit Interface
4690: ** DEPRECATED
4691: **
4692: ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
4693: ** interface. This routine is provided for historical compatibility
4694: ** only. All new applications should use the
4695: ** [sqlite3_soft_heap_limit64()] interface rather than this one.
4696: */
4697: SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
4698:
4699:
4700: /*
4701: ** CAPI3REF: Extract Metadata About A Column Of A Table
4702: **
4703: ** ^This routine returns metadata about a specific column of a specific
4704: ** database table accessible using the [database connection] handle
4705: ** passed as the first function argument.
4706: **
4707: ** ^The column is identified by the second, third and fourth parameters to
4708: ** this function. ^The second parameter is either the name of the database
4709: ** (i.e. "main", "temp", or an attached database) containing the specified
4710: ** table or NULL. ^If it is NULL, then all attached databases are searched
4711: ** for the table using the same algorithm used by the database engine to
4712: ** resolve unqualified table references.
4713: **
4714: ** ^The third and fourth parameters to this function are the table and column
4715: ** name of the desired column, respectively. Neither of these parameters
4716: ** may be NULL.
4717: **
4718: ** ^Metadata is returned by writing to the memory locations passed as the 5th
4719: ** and subsequent parameters to this function. ^Any of these arguments may be
4720: ** NULL, in which case the corresponding element of metadata is omitted.
4721: **
4722: ** ^(<blockquote>
4723: ** <table border="1">
4724: ** <tr><th> Parameter <th> Output<br>Type <th> Description
4725: **
4726: ** <tr><td> 5th <td> const char* <td> Data type
4727: ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
4728: ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
4729: ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
4730: ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
4731: ** </table>
4732: ** </blockquote>)^
4733: **
4734: ** ^The memory pointed to by the character pointers returned for the
4735: ** declaration type and collation sequence is valid only until the next
4736: ** call to any SQLite API function.
4737: **
4738: ** ^If the specified table is actually a view, an [error code] is returned.
4739: **
4740: ** ^If the specified column is "rowid", "oid" or "_rowid_" and an
4741: ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
4742: ** parameters are set for the explicitly declared column. ^(If there is no
4743: ** explicitly declared [INTEGER PRIMARY KEY] column, then the output
4744: ** parameters are set as follows:
4745: **
4746: ** <pre>
4747: ** data type: "INTEGER"
4748: ** collation sequence: "BINARY"
4749: ** not null: 0
4750: ** primary key: 1
4751: ** auto increment: 0
4752: ** </pre>)^
4753: **
4754: ** ^(This function may load one or more schemas from database files. If an
4755: ** error occurs during this process, or if the requested table or column
4756: ** cannot be found, an [error code] is returned and an error message left
4757: ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
4758: **
4759: ** ^This API is only available if the library was compiled with the
4760: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
4761: */
4762: SQLITE_API int sqlite3_table_column_metadata(
4763: sqlite3 *db, /* Connection handle */
4764: const char *zDbName, /* Database name or NULL */
4765: const char *zTableName, /* Table name */
4766: const char *zColumnName, /* Column name */
4767: char const **pzDataType, /* OUTPUT: Declared data type */
4768: char const **pzCollSeq, /* OUTPUT: Collation sequence name */
4769: int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
4770: int *pPrimaryKey, /* OUTPUT: True if column part of PK */
4771: int *pAutoinc /* OUTPUT: True if column is auto-increment */
4772: );
4773:
4774: /*
4775: ** CAPI3REF: Load An Extension
4776: **
4777: ** ^This interface loads an SQLite extension library from the named file.
4778: **
4779: ** ^The sqlite3_load_extension() interface attempts to load an
4780: ** SQLite extension library contained in the file zFile.
4781: **
4782: ** ^The entry point is zProc.
4783: ** ^zProc may be 0, in which case the name of the entry point
4784: ** defaults to "sqlite3_extension_init".
4785: ** ^The sqlite3_load_extension() interface returns
4786: ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
4787: ** ^If an error occurs and pzErrMsg is not 0, then the
4788: ** [sqlite3_load_extension()] interface shall attempt to
4789: ** fill *pzErrMsg with error message text stored in memory
4790: ** obtained from [sqlite3_malloc()]. The calling function
4791: ** should free this memory by calling [sqlite3_free()].
4792: **
4793: ** ^Extension loading must be enabled using
4794: ** [sqlite3_enable_load_extension()] prior to calling this API,
4795: ** otherwise an error will be returned.
4796: **
4797: ** See also the [load_extension() SQL function].
4798: */
4799: SQLITE_API int sqlite3_load_extension(
4800: sqlite3 *db, /* Load the extension into this database connection */
4801: const char *zFile, /* Name of the shared library containing extension */
4802: const char *zProc, /* Entry point. Derived from zFile if 0 */
4803: char **pzErrMsg /* Put error message here if not 0 */
4804: );
4805:
4806: /*
4807: ** CAPI3REF: Enable Or Disable Extension Loading
4808: **
4809: ** ^So as not to open security holes in older applications that are
4810: ** unprepared to deal with extension loading, and as a means of disabling
4811: ** extension loading while evaluating user-entered SQL, the following API
4812: ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
4813: **
4814: ** ^Extension loading is off by default. See ticket #1863.
4815: ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
4816: ** to turn extension loading on and call it with onoff==0 to turn
4817: ** it back off again.
4818: */
4819: SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
4820:
4821: /*
4822: ** CAPI3REF: Automatically Load Statically Linked Extensions
4823: **
4824: ** ^This interface causes the xEntryPoint() function to be invoked for
4825: ** each new [database connection] that is created. The idea here is that
4826: ** xEntryPoint() is the entry point for a statically linked SQLite extension
4827: ** that is to be automatically loaded into all new database connections.
4828: **
4829: ** ^(Even though the function prototype shows that xEntryPoint() takes
4830: ** no arguments and returns void, SQLite invokes xEntryPoint() with three
4831: ** arguments and expects and integer result as if the signature of the
4832: ** entry point where as follows:
4833: **
4834: ** <blockquote><pre>
4835: ** int xEntryPoint(
4836: ** sqlite3 *db,
4837: ** const char **pzErrMsg,
4838: ** const struct sqlite3_api_routines *pThunk
4839: ** );
4840: ** </pre></blockquote>)^
4841: **
4842: ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
4843: ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
4844: ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
4845: ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
4846: ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
4847: ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
4848: ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
4849: **
4850: ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
4851: ** on the list of automatic extensions is a harmless no-op. ^No entry point
4852: ** will be called more than once for each database connection that is opened.
4853: **
4854: ** See also: [sqlite3_reset_auto_extension()].
4855: */
4856: SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
4857:
4858: /*
4859: ** CAPI3REF: Reset Automatic Extension Loading
4860: **
4861: ** ^This interface disables all automatic extensions previously
4862: ** registered using [sqlite3_auto_extension()].
4863: */
4864: SQLITE_API void sqlite3_reset_auto_extension(void);
4865:
4866: /*
4867: ** The interface to the virtual-table mechanism is currently considered
4868: ** to be experimental. The interface might change in incompatible ways.
4869: ** If this is a problem for you, do not use the interface at this time.
4870: **
4871: ** When the virtual-table mechanism stabilizes, we will declare the
4872: ** interface fixed, support it indefinitely, and remove this comment.
4873: */
4874:
4875: /*
4876: ** Structures used by the virtual table interface
4877: */
4878: typedef struct sqlite3_vtab sqlite3_vtab;
4879: typedef struct sqlite3_index_info sqlite3_index_info;
4880: typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
4881: typedef struct sqlite3_module sqlite3_module;
4882:
4883: /*
4884: ** CAPI3REF: Virtual Table Object
4885: ** KEYWORDS: sqlite3_module {virtual table module}
4886: **
4887: ** This structure, sometimes called a "virtual table module",
4888: ** defines the implementation of a [virtual tables].
4889: ** This structure consists mostly of methods for the module.
4890: **
4891: ** ^A virtual table module is created by filling in a persistent
4892: ** instance of this structure and passing a pointer to that instance
4893: ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
4894: ** ^The registration remains valid until it is replaced by a different
4895: ** module or until the [database connection] closes. The content
4896: ** of this structure must not change while it is registered with
4897: ** any database connection.
4898: */
4899: struct sqlite3_module {
4900: int iVersion;
4901: int (*xCreate)(sqlite3*, void *pAux,
4902: int argc, const char *const*argv,
4903: sqlite3_vtab **ppVTab, char**);
4904: int (*xConnect)(sqlite3*, void *pAux,
4905: int argc, const char *const*argv,
4906: sqlite3_vtab **ppVTab, char**);
4907: int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
4908: int (*xDisconnect)(sqlite3_vtab *pVTab);
4909: int (*xDestroy)(sqlite3_vtab *pVTab);
4910: int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
4911: int (*xClose)(sqlite3_vtab_cursor*);
4912: int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
4913: int argc, sqlite3_value **argv);
4914: int (*xNext)(sqlite3_vtab_cursor*);
4915: int (*xEof)(sqlite3_vtab_cursor*);
4916: int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
4917: int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
4918: int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
4919: int (*xBegin)(sqlite3_vtab *pVTab);
4920: int (*xSync)(sqlite3_vtab *pVTab);
4921: int (*xCommit)(sqlite3_vtab *pVTab);
4922: int (*xRollback)(sqlite3_vtab *pVTab);
4923: int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
4924: void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
4925: void **ppArg);
4926: int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
4927: /* The methods above are in version 1 of the sqlite_module object. Those
4928: ** below are for version 2 and greater. */
4929: int (*xSavepoint)(sqlite3_vtab *pVTab, int);
4930: int (*xRelease)(sqlite3_vtab *pVTab, int);
4931: int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
4932: };
4933:
4934: /*
4935: ** CAPI3REF: Virtual Table Indexing Information
4936: ** KEYWORDS: sqlite3_index_info
4937: **
4938: ** The sqlite3_index_info structure and its substructures is used as part
4939: ** of the [virtual table] interface to
4940: ** pass information into and receive the reply from the [xBestIndex]
4941: ** method of a [virtual table module]. The fields under **Inputs** are the
4942: ** inputs to xBestIndex and are read-only. xBestIndex inserts its
4943: ** results into the **Outputs** fields.
4944: **
4945: ** ^(The aConstraint[] array records WHERE clause constraints of the form:
4946: **
4947: ** <blockquote>column OP expr</blockquote>
4948: **
4949: ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
4950: ** stored in aConstraint[].op using one of the
4951: ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
4952: ** ^(The index of the column is stored in
4953: ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
4954: ** expr on the right-hand side can be evaluated (and thus the constraint
4955: ** is usable) and false if it cannot.)^
4956: **
4957: ** ^The optimizer automatically inverts terms of the form "expr OP column"
4958: ** and makes other simplifications to the WHERE clause in an attempt to
4959: ** get as many WHERE clause terms into the form shown above as possible.
4960: ** ^The aConstraint[] array only reports WHERE clause terms that are
4961: ** relevant to the particular virtual table being queried.
4962: **
4963: ** ^Information about the ORDER BY clause is stored in aOrderBy[].
4964: ** ^Each term of aOrderBy records a column of the ORDER BY clause.
4965: **
4966: ** The [xBestIndex] method must fill aConstraintUsage[] with information
4967: ** about what parameters to pass to xFilter. ^If argvIndex>0 then
4968: ** the right-hand side of the corresponding aConstraint[] is evaluated
4969: ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
4970: ** is true, then the constraint is assumed to be fully handled by the
4971: ** virtual table and is not checked again by SQLite.)^
4972: **
4973: ** ^The idxNum and idxPtr values are recorded and passed into the
4974: ** [xFilter] method.
4975: ** ^[sqlite3_free()] is used to free idxPtr if and only if
4976: ** needToFreeIdxPtr is true.
4977: **
4978: ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
4979: ** the correct order to satisfy the ORDER BY clause so that no separate
4980: ** sorting step is required.
4981: **
4982: ** ^The estimatedCost value is an estimate of the cost of doing the
4983: ** particular lookup. A full scan of a table with N entries should have
4984: ** a cost of N. A binary search of a table of N entries should have a
4985: ** cost of approximately log(N).
4986: */
4987: struct sqlite3_index_info {
4988: /* Inputs */
4989: int nConstraint; /* Number of entries in aConstraint */
4990: struct sqlite3_index_constraint {
4991: int iColumn; /* Column on left-hand side of constraint */
4992: unsigned char op; /* Constraint operator */
4993: unsigned char usable; /* True if this constraint is usable */
4994: int iTermOffset; /* Used internally - xBestIndex should ignore */
4995: } *aConstraint; /* Table of WHERE clause constraints */
4996: int nOrderBy; /* Number of terms in the ORDER BY clause */
4997: struct sqlite3_index_orderby {
4998: int iColumn; /* Column number */
4999: unsigned char desc; /* True for DESC. False for ASC. */
5000: } *aOrderBy; /* The ORDER BY clause */
5001: /* Outputs */
5002: struct sqlite3_index_constraint_usage {
5003: int argvIndex; /* if >0, constraint is part of argv to xFilter */
5004: unsigned char omit; /* Do not code a test for this constraint */
5005: } *aConstraintUsage;
5006: int idxNum; /* Number used to identify the index */
5007: char *idxStr; /* String, possibly obtained from sqlite3_malloc */
5008: int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
5009: int orderByConsumed; /* True if output is already ordered */
5010: double estimatedCost; /* Estimated cost of using this index */
5011: };
5012:
5013: /*
5014: ** CAPI3REF: Virtual Table Constraint Operator Codes
5015: **
5016: ** These macros defined the allowed values for the
5017: ** [sqlite3_index_info].aConstraint[].op field. Each value represents
5018: ** an operator that is part of a constraint term in the wHERE clause of
5019: ** a query that uses a [virtual table].
5020: */
5021: #define SQLITE_INDEX_CONSTRAINT_EQ 2
5022: #define SQLITE_INDEX_CONSTRAINT_GT 4
5023: #define SQLITE_INDEX_CONSTRAINT_LE 8
5024: #define SQLITE_INDEX_CONSTRAINT_LT 16
5025: #define SQLITE_INDEX_CONSTRAINT_GE 32
5026: #define SQLITE_INDEX_CONSTRAINT_MATCH 64
5027:
5028: /*
5029: ** CAPI3REF: Register A Virtual Table Implementation
5030: **
5031: ** ^These routines are used to register a new [virtual table module] name.
5032: ** ^Module names must be registered before
5033: ** creating a new [virtual table] using the module and before using a
5034: ** preexisting [virtual table] for the module.
5035: **
5036: ** ^The module name is registered on the [database connection] specified
5037: ** by the first parameter. ^The name of the module is given by the
5038: ** second parameter. ^The third parameter is a pointer to
5039: ** the implementation of the [virtual table module]. ^The fourth
5040: ** parameter is an arbitrary client data pointer that is passed through
5041: ** into the [xCreate] and [xConnect] methods of the virtual table module
5042: ** when a new virtual table is be being created or reinitialized.
5043: **
5044: ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
5045: ** is a pointer to a destructor for the pClientData. ^SQLite will
5046: ** invoke the destructor function (if it is not NULL) when SQLite
5047: ** no longer needs the pClientData pointer. ^The destructor will also
5048: ** be invoked if the call to sqlite3_create_module_v2() fails.
5049: ** ^The sqlite3_create_module()
5050: ** interface is equivalent to sqlite3_create_module_v2() with a NULL
5051: ** destructor.
5052: */
5053: SQLITE_API int sqlite3_create_module(
5054: sqlite3 *db, /* SQLite connection to register module with */
5055: const char *zName, /* Name of the module */
5056: const sqlite3_module *p, /* Methods for the module */
5057: void *pClientData /* Client data for xCreate/xConnect */
5058: );
5059: SQLITE_API int sqlite3_create_module_v2(
5060: sqlite3 *db, /* SQLite connection to register module with */
5061: const char *zName, /* Name of the module */
5062: const sqlite3_module *p, /* Methods for the module */
5063: void *pClientData, /* Client data for xCreate/xConnect */
5064: void(*xDestroy)(void*) /* Module destructor function */
5065: );
5066:
5067: /*
5068: ** CAPI3REF: Virtual Table Instance Object
5069: ** KEYWORDS: sqlite3_vtab
5070: **
5071: ** Every [virtual table module] implementation uses a subclass
5072: ** of this object to describe a particular instance
5073: ** of the [virtual table]. Each subclass will
5074: ** be tailored to the specific needs of the module implementation.
5075: ** The purpose of this superclass is to define certain fields that are
5076: ** common to all module implementations.
5077: **
5078: ** ^Virtual tables methods can set an error message by assigning a
5079: ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
5080: ** take care that any prior string is freed by a call to [sqlite3_free()]
5081: ** prior to assigning a new string to zErrMsg. ^After the error message
5082: ** is delivered up to the client application, the string will be automatically
5083: ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
5084: */
5085: struct sqlite3_vtab {
5086: const sqlite3_module *pModule; /* The module for this virtual table */
5087: int nRef; /* NO LONGER USED */
5088: char *zErrMsg; /* Error message from sqlite3_mprintf() */
5089: /* Virtual table implementations will typically add additional fields */
5090: };
5091:
5092: /*
5093: ** CAPI3REF: Virtual Table Cursor Object
5094: ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
5095: **
5096: ** Every [virtual table module] implementation uses a subclass of the
5097: ** following structure to describe cursors that point into the
5098: ** [virtual table] and are used
5099: ** to loop through the virtual table. Cursors are created using the
5100: ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
5101: ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
5102: ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
5103: ** of the module. Each module implementation will define
5104: ** the content of a cursor structure to suit its own needs.
5105: **
5106: ** This superclass exists in order to define fields of the cursor that
5107: ** are common to all implementations.
5108: */
5109: struct sqlite3_vtab_cursor {
5110: sqlite3_vtab *pVtab; /* Virtual table of this cursor */
5111: /* Virtual table implementations will typically add additional fields */
5112: };
5113:
5114: /*
5115: ** CAPI3REF: Declare The Schema Of A Virtual Table
5116: **
5117: ** ^The [xCreate] and [xConnect] methods of a
5118: ** [virtual table module] call this interface
5119: ** to declare the format (the names and datatypes of the columns) of
5120: ** the virtual tables they implement.
5121: */
5122: SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
5123:
5124: /*
5125: ** CAPI3REF: Overload A Function For A Virtual Table
5126: **
5127: ** ^(Virtual tables can provide alternative implementations of functions
5128: ** using the [xFindFunction] method of the [virtual table module].
5129: ** But global versions of those functions
5130: ** must exist in order to be overloaded.)^
5131: **
5132: ** ^(This API makes sure a global version of a function with a particular
5133: ** name and number of parameters exists. If no such function exists
5134: ** before this API is called, a new function is created.)^ ^The implementation
5135: ** of the new function always causes an exception to be thrown. So
5136: ** the new function is not good for anything by itself. Its only
5137: ** purpose is to be a placeholder function that can be overloaded
5138: ** by a [virtual table].
5139: */
5140: SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
5141:
5142: /*
5143: ** The interface to the virtual-table mechanism defined above (back up
5144: ** to a comment remarkably similar to this one) is currently considered
5145: ** to be experimental. The interface might change in incompatible ways.
5146: ** If this is a problem for you, do not use the interface at this time.
5147: **
5148: ** When the virtual-table mechanism stabilizes, we will declare the
5149: ** interface fixed, support it indefinitely, and remove this comment.
5150: */
5151:
5152: /*
5153: ** CAPI3REF: A Handle To An Open BLOB
5154: ** KEYWORDS: {BLOB handle} {BLOB handles}
5155: **
5156: ** An instance of this object represents an open BLOB on which
5157: ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5158: ** ^Objects of this type are created by [sqlite3_blob_open()]
5159: ** and destroyed by [sqlite3_blob_close()].
5160: ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5161: ** can be used to read or write small subsections of the BLOB.
5162: ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5163: */
5164: typedef struct sqlite3_blob sqlite3_blob;
5165:
5166: /*
5167: ** CAPI3REF: Open A BLOB For Incremental I/O
5168: **
5169: ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
5170: ** in row iRow, column zColumn, table zTable in database zDb;
5171: ** in other words, the same BLOB that would be selected by:
5172: **
5173: ** <pre>
5174: ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
5175: ** </pre>)^
5176: **
5177: ** ^If the flags parameter is non-zero, then the BLOB is opened for read
5178: ** and write access. ^If it is zero, the BLOB is opened for read access.
5179: ** ^It is not possible to open a column that is part of an index or primary
5180: ** key for writing. ^If [foreign key constraints] are enabled, it is
5181: ** not possible to open a column that is part of a [child key] for writing.
5182: **
5183: ** ^Note that the database name is not the filename that contains
5184: ** the database but rather the symbolic name of the database that
5185: ** appears after the AS keyword when the database is connected using [ATTACH].
5186: ** ^For the main database file, the database name is "main".
5187: ** ^For TEMP tables, the database name is "temp".
5188: **
5189: ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
5190: ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
5191: ** to be a null pointer.)^
5192: ** ^This function sets the [database connection] error code and message
5193: ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
5194: ** functions. ^Note that the *ppBlob variable is always initialized in a
5195: ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
5196: ** regardless of the success or failure of this routine.
5197: **
5198: ** ^(If the row that a BLOB handle points to is modified by an
5199: ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
5200: ** then the BLOB handle is marked as "expired".
5201: ** This is true if any column of the row is changed, even a column
5202: ** other than the one the BLOB handle is open on.)^
5203: ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
5204: ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
5205: ** ^(Changes written into a BLOB prior to the BLOB expiring are not
5206: ** rolled back by the expiration of the BLOB. Such changes will eventually
5207: ** commit if the transaction continues to completion.)^
5208: **
5209: ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
5210: ** the opened blob. ^The size of a blob may not be changed by this
5211: ** interface. Use the [UPDATE] SQL command to change the size of a
5212: ** blob.
5213: **
5214: ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
5215: ** and the built-in [zeroblob] SQL function can be used, if desired,
5216: ** to create an empty, zero-filled blob in which to read or write using
5217: ** this interface.
5218: **
5219: ** To avoid a resource leak, every open [BLOB handle] should eventually
5220: ** be released by a call to [sqlite3_blob_close()].
5221: */
5222: SQLITE_API int sqlite3_blob_open(
5223: sqlite3*,
5224: const char *zDb,
5225: const char *zTable,
5226: const char *zColumn,
5227: sqlite3_int64 iRow,
5228: int flags,
5229: sqlite3_blob **ppBlob
5230: );
5231:
5232: /*
5233: ** CAPI3REF: Move a BLOB Handle to a New Row
5234: **
5235: ** ^This function is used to move an existing blob handle so that it points
5236: ** to a different row of the same database table. ^The new row is identified
5237: ** by the rowid value passed as the second argument. Only the row can be
5238: ** changed. ^The database, table and column on which the blob handle is open
5239: ** remain the same. Moving an existing blob handle to a new row can be
5240: ** faster than closing the existing handle and opening a new one.
5241: **
5242: ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
5243: ** it must exist and there must be either a blob or text value stored in
5244: ** the nominated column.)^ ^If the new row is not present in the table, or if
5245: ** it does not contain a blob or text value, or if another error occurs, an
5246: ** SQLite error code is returned and the blob handle is considered aborted.
5247: ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
5248: ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
5249: ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
5250: ** always returns zero.
5251: **
5252: ** ^This function sets the database handle error code and message.
5253: */
5254: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
5255:
5256: /*
5257: ** CAPI3REF: Close A BLOB Handle
5258: **
5259: ** ^Closes an open [BLOB handle].
5260: **
5261: ** ^Closing a BLOB shall cause the current transaction to commit
5262: ** if there are no other BLOBs, no pending prepared statements, and the
5263: ** database connection is in [autocommit mode].
5264: ** ^If any writes were made to the BLOB, they might be held in cache
5265: ** until the close operation if they will fit.
5266: **
5267: ** ^(Closing the BLOB often forces the changes
5268: ** out to disk and so if any I/O errors occur, they will likely occur
5269: ** at the time when the BLOB is closed. Any errors that occur during
5270: ** closing are reported as a non-zero return value.)^
5271: **
5272: ** ^(The BLOB is closed unconditionally. Even if this routine returns
5273: ** an error code, the BLOB is still closed.)^
5274: **
5275: ** ^Calling this routine with a null pointer (such as would be returned
5276: ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
5277: */
5278: SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
5279:
5280: /*
5281: ** CAPI3REF: Return The Size Of An Open BLOB
5282: **
5283: ** ^Returns the size in bytes of the BLOB accessible via the
5284: ** successfully opened [BLOB handle] in its only argument. ^The
5285: ** incremental blob I/O routines can only read or overwriting existing
5286: ** blob content; they cannot change the size of a blob.
5287: **
5288: ** This routine only works on a [BLOB handle] which has been created
5289: ** by a prior successful call to [sqlite3_blob_open()] and which has not
5290: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5291: ** to this routine results in undefined and probably undesirable behavior.
5292: */
5293: SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
5294:
5295: /*
5296: ** CAPI3REF: Read Data From A BLOB Incrementally
5297: **
5298: ** ^(This function is used to read data from an open [BLOB handle] into a
5299: ** caller-supplied buffer. N bytes of data are copied into buffer Z
5300: ** from the open BLOB, starting at offset iOffset.)^
5301: **
5302: ** ^If offset iOffset is less than N bytes from the end of the BLOB,
5303: ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
5304: ** less than zero, [SQLITE_ERROR] is returned and no data is read.
5305: ** ^The size of the blob (and hence the maximum value of N+iOffset)
5306: ** can be determined using the [sqlite3_blob_bytes()] interface.
5307: **
5308: ** ^An attempt to read from an expired [BLOB handle] fails with an
5309: ** error code of [SQLITE_ABORT].
5310: **
5311: ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
5312: ** Otherwise, an [error code] or an [extended error code] is returned.)^
5313: **
5314: ** This routine only works on a [BLOB handle] which has been created
5315: ** by a prior successful call to [sqlite3_blob_open()] and which has not
5316: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5317: ** to this routine results in undefined and probably undesirable behavior.
5318: **
5319: ** See also: [sqlite3_blob_write()].
5320: */
5321: SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
5322:
5323: /*
5324: ** CAPI3REF: Write Data Into A BLOB Incrementally
5325: **
5326: ** ^This function is used to write data into an open [BLOB handle] from a
5327: ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
5328: ** into the open BLOB, starting at offset iOffset.
5329: **
5330: ** ^If the [BLOB handle] passed as the first argument was not opened for
5331: ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
5332: ** this function returns [SQLITE_READONLY].
5333: **
5334: ** ^This function may only modify the contents of the BLOB; it is
5335: ** not possible to increase the size of a BLOB using this API.
5336: ** ^If offset iOffset is less than N bytes from the end of the BLOB,
5337: ** [SQLITE_ERROR] is returned and no data is written. ^If N is
5338: ** less than zero [SQLITE_ERROR] is returned and no data is written.
5339: ** The size of the BLOB (and hence the maximum value of N+iOffset)
5340: ** can be determined using the [sqlite3_blob_bytes()] interface.
5341: **
5342: ** ^An attempt to write to an expired [BLOB handle] fails with an
5343: ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
5344: ** before the [BLOB handle] expired are not rolled back by the
5345: ** expiration of the handle, though of course those changes might
5346: ** have been overwritten by the statement that expired the BLOB handle
5347: ** or by other independent statements.
5348: **
5349: ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
5350: ** Otherwise, an [error code] or an [extended error code] is returned.)^
5351: **
5352: ** This routine only works on a [BLOB handle] which has been created
5353: ** by a prior successful call to [sqlite3_blob_open()] and which has not
5354: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5355: ** to this routine results in undefined and probably undesirable behavior.
5356: **
5357: ** See also: [sqlite3_blob_read()].
5358: */
5359: SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
5360:
5361: /*
5362: ** CAPI3REF: Virtual File System Objects
5363: **
5364: ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
5365: ** that SQLite uses to interact
5366: ** with the underlying operating system. Most SQLite builds come with a
5367: ** single default VFS that is appropriate for the host computer.
5368: ** New VFSes can be registered and existing VFSes can be unregistered.
5369: ** The following interfaces are provided.
5370: **
5371: ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
5372: ** ^Names are case sensitive.
5373: ** ^Names are zero-terminated UTF-8 strings.
5374: ** ^If there is no match, a NULL pointer is returned.
5375: ** ^If zVfsName is NULL then the default VFS is returned.
5376: **
5377: ** ^New VFSes are registered with sqlite3_vfs_register().
5378: ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
5379: ** ^The same VFS can be registered multiple times without injury.
5380: ** ^To make an existing VFS into the default VFS, register it again
5381: ** with the makeDflt flag set. If two different VFSes with the
5382: ** same name are registered, the behavior is undefined. If a
5383: ** VFS is registered with a name that is NULL or an empty string,
5384: ** then the behavior is undefined.
5385: **
5386: ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
5387: ** ^(If the default VFS is unregistered, another VFS is chosen as
5388: ** the default. The choice for the new VFS is arbitrary.)^
5389: */
5390: SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
5391: SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
5392: SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
5393:
5394: /*
5395: ** CAPI3REF: Mutexes
5396: **
5397: ** The SQLite core uses these routines for thread
5398: ** synchronization. Though they are intended for internal
5399: ** use by SQLite, code that links against SQLite is
5400: ** permitted to use any of these routines.
5401: **
5402: ** The SQLite source code contains multiple implementations
5403: ** of these mutex routines. An appropriate implementation
5404: ** is selected automatically at compile-time. ^(The following
5405: ** implementations are available in the SQLite core:
5406: **
5407: ** <ul>
5408: ** <li> SQLITE_MUTEX_OS2
5409: ** <li> SQLITE_MUTEX_PTHREADS
5410: ** <li> SQLITE_MUTEX_W32
5411: ** <li> SQLITE_MUTEX_NOOP
5412: ** </ul>)^
5413: **
5414: ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
5415: ** that does no real locking and is appropriate for use in
5416: ** a single-threaded application. ^The SQLITE_MUTEX_OS2,
5417: ** SQLITE_MUTEX_PTHREADS, and SQLITE_MUTEX_W32 implementations
5418: ** are appropriate for use on OS/2, Unix, and Windows.
5419: **
5420: ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
5421: ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
5422: ** implementation is included with the library. In this case the
5423: ** application must supply a custom mutex implementation using the
5424: ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
5425: ** before calling sqlite3_initialize() or any other public sqlite3_
5426: ** function that calls sqlite3_initialize().)^
5427: **
5428: ** ^The sqlite3_mutex_alloc() routine allocates a new
5429: ** mutex and returns a pointer to it. ^If it returns NULL
5430: ** that means that a mutex could not be allocated. ^SQLite
5431: ** will unwind its stack and return an error. ^(The argument
5432: ** to sqlite3_mutex_alloc() is one of these integer constants:
5433: **
5434: ** <ul>
5435: ** <li> SQLITE_MUTEX_FAST
5436: ** <li> SQLITE_MUTEX_RECURSIVE
5437: ** <li> SQLITE_MUTEX_STATIC_MASTER
5438: ** <li> SQLITE_MUTEX_STATIC_MEM
5439: ** <li> SQLITE_MUTEX_STATIC_MEM2
5440: ** <li> SQLITE_MUTEX_STATIC_PRNG
5441: ** <li> SQLITE_MUTEX_STATIC_LRU
5442: ** <li> SQLITE_MUTEX_STATIC_LRU2
5443: ** </ul>)^
5444: **
5445: ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
5446: ** cause sqlite3_mutex_alloc() to create
5447: ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
5448: ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
5449: ** The mutex implementation does not need to make a distinction
5450: ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
5451: ** not want to. ^SQLite will only request a recursive mutex in
5452: ** cases where it really needs one. ^If a faster non-recursive mutex
5453: ** implementation is available on the host platform, the mutex subsystem
5454: ** might return such a mutex in response to SQLITE_MUTEX_FAST.
5455: **
5456: ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
5457: ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
5458: ** a pointer to a static preexisting mutex. ^Six static mutexes are
5459: ** used by the current version of SQLite. Future versions of SQLite
5460: ** may add additional static mutexes. Static mutexes are for internal
5461: ** use by SQLite only. Applications that use SQLite mutexes should
5462: ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
5463: ** SQLITE_MUTEX_RECURSIVE.
5464: **
5465: ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
5466: ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
5467: ** returns a different mutex on every call. ^But for the static
5468: ** mutex types, the same mutex is returned on every call that has
5469: ** the same type number.
5470: **
5471: ** ^The sqlite3_mutex_free() routine deallocates a previously
5472: ** allocated dynamic mutex. ^SQLite is careful to deallocate every
5473: ** dynamic mutex that it allocates. The dynamic mutexes must not be in
5474: ** use when they are deallocated. Attempting to deallocate a static
5475: ** mutex results in undefined behavior. ^SQLite never deallocates
5476: ** a static mutex.
5477: **
5478: ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
5479: ** to enter a mutex. ^If another thread is already within the mutex,
5480: ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
5481: ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
5482: ** upon successful entry. ^(Mutexes created using
5483: ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
5484: ** In such cases the,
5485: ** mutex must be exited an equal number of times before another thread
5486: ** can enter.)^ ^(If the same thread tries to enter any other
5487: ** kind of mutex more than once, the behavior is undefined.
5488: ** SQLite will never exhibit
5489: ** such behavior in its own use of mutexes.)^
5490: **
5491: ** ^(Some systems (for example, Windows 95) do not support the operation
5492: ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
5493: ** will always return SQLITE_BUSY. The SQLite core only ever uses
5494: ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
5495: **
5496: ** ^The sqlite3_mutex_leave() routine exits a mutex that was
5497: ** previously entered by the same thread. ^(The behavior
5498: ** is undefined if the mutex is not currently entered by the
5499: ** calling thread or is not currently allocated. SQLite will
5500: ** never do either.)^
5501: **
5502: ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
5503: ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
5504: ** behave as no-ops.
5505: **
5506: ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
5507: */
5508: SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
5509: SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
5510: SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
5511: SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
5512: SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
5513:
5514: /*
5515: ** CAPI3REF: Mutex Methods Object
5516: **
5517: ** An instance of this structure defines the low-level routines
5518: ** used to allocate and use mutexes.
5519: **
5520: ** Usually, the default mutex implementations provided by SQLite are
5521: ** sufficient, however the user has the option of substituting a custom
5522: ** implementation for specialized deployments or systems for which SQLite
5523: ** does not provide a suitable implementation. In this case, the user
5524: ** creates and populates an instance of this structure to pass
5525: ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
5526: ** Additionally, an instance of this structure can be used as an
5527: ** output variable when querying the system for the current mutex
5528: ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
5529: **
5530: ** ^The xMutexInit method defined by this structure is invoked as
5531: ** part of system initialization by the sqlite3_initialize() function.
5532: ** ^The xMutexInit routine is called by SQLite exactly once for each
5533: ** effective call to [sqlite3_initialize()].
5534: **
5535: ** ^The xMutexEnd method defined by this structure is invoked as
5536: ** part of system shutdown by the sqlite3_shutdown() function. The
5537: ** implementation of this method is expected to release all outstanding
5538: ** resources obtained by the mutex methods implementation, especially
5539: ** those obtained by the xMutexInit method. ^The xMutexEnd()
5540: ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
5541: **
5542: ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
5543: ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
5544: ** xMutexNotheld) implement the following interfaces (respectively):
5545: **
5546: ** <ul>
5547: ** <li> [sqlite3_mutex_alloc()] </li>
5548: ** <li> [sqlite3_mutex_free()] </li>
5549: ** <li> [sqlite3_mutex_enter()] </li>
5550: ** <li> [sqlite3_mutex_try()] </li>
5551: ** <li> [sqlite3_mutex_leave()] </li>
5552: ** <li> [sqlite3_mutex_held()] </li>
5553: ** <li> [sqlite3_mutex_notheld()] </li>
5554: ** </ul>)^
5555: **
5556: ** The only difference is that the public sqlite3_XXX functions enumerated
5557: ** above silently ignore any invocations that pass a NULL pointer instead
5558: ** of a valid mutex handle. The implementations of the methods defined
5559: ** by this structure are not required to handle this case, the results
5560: ** of passing a NULL pointer instead of a valid mutex handle are undefined
5561: ** (i.e. it is acceptable to provide an implementation that segfaults if
5562: ** it is passed a NULL pointer).
5563: **
5564: ** The xMutexInit() method must be threadsafe. ^It must be harmless to
5565: ** invoke xMutexInit() multiple times within the same process and without
5566: ** intervening calls to xMutexEnd(). Second and subsequent calls to
5567: ** xMutexInit() must be no-ops.
5568: **
5569: ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
5570: ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory
5571: ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
5572: ** memory allocation for a fast or recursive mutex.
5573: **
5574: ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
5575: ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
5576: ** If xMutexInit fails in any way, it is expected to clean up after itself
5577: ** prior to returning.
5578: */
5579: typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
5580: struct sqlite3_mutex_methods {
5581: int (*xMutexInit)(void);
5582: int (*xMutexEnd)(void);
5583: sqlite3_mutex *(*xMutexAlloc)(int);
5584: void (*xMutexFree)(sqlite3_mutex *);
5585: void (*xMutexEnter)(sqlite3_mutex *);
5586: int (*xMutexTry)(sqlite3_mutex *);
5587: void (*xMutexLeave)(sqlite3_mutex *);
5588: int (*xMutexHeld)(sqlite3_mutex *);
5589: int (*xMutexNotheld)(sqlite3_mutex *);
5590: };
5591:
5592: /*
5593: ** CAPI3REF: Mutex Verification Routines
5594: **
5595: ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
5596: ** are intended for use inside assert() statements. ^The SQLite core
5597: ** never uses these routines except inside an assert() and applications
5598: ** are advised to follow the lead of the core. ^The SQLite core only
5599: ** provides implementations for these routines when it is compiled
5600: ** with the SQLITE_DEBUG flag. ^External mutex implementations
5601: ** are only required to provide these routines if SQLITE_DEBUG is
5602: ** defined and if NDEBUG is not defined.
5603: **
5604: ** ^These routines should return true if the mutex in their argument
5605: ** is held or not held, respectively, by the calling thread.
5606: **
5607: ** ^The implementation is not required to provide versions of these
5608: ** routines that actually work. If the implementation does not provide working
5609: ** versions of these routines, it should at least provide stubs that always
5610: ** return true so that one does not get spurious assertion failures.
5611: **
5612: ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
5613: ** the routine should return 1. This seems counter-intuitive since
5614: ** clearly the mutex cannot be held if it does not exist. But
5615: ** the reason the mutex does not exist is because the build is not
5616: ** using mutexes. And we do not want the assert() containing the
5617: ** call to sqlite3_mutex_held() to fail, so a non-zero return is
5618: ** the appropriate thing to do. ^The sqlite3_mutex_notheld()
5619: ** interface should also return 1 when given a NULL pointer.
5620: */
5621: #ifndef NDEBUG
5622: SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
5623: SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
5624: #endif
5625:
5626: /*
5627: ** CAPI3REF: Mutex Types
5628: **
5629: ** The [sqlite3_mutex_alloc()] interface takes a single argument
5630: ** which is one of these integer constants.
5631: **
5632: ** The set of static mutexes may change from one SQLite release to the
5633: ** next. Applications that override the built-in mutex logic must be
5634: ** prepared to accommodate additional static mutexes.
5635: */
5636: #define SQLITE_MUTEX_FAST 0
5637: #define SQLITE_MUTEX_RECURSIVE 1
5638: #define SQLITE_MUTEX_STATIC_MASTER 2
5639: #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
5640: #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
5641: #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
5642: #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */
5643: #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
5644: #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
5645: #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
5646:
5647: /*
5648: ** CAPI3REF: Retrieve the mutex for a database connection
5649: **
5650: ** ^This interface returns a pointer the [sqlite3_mutex] object that
5651: ** serializes access to the [database connection] given in the argument
5652: ** when the [threading mode] is Serialized.
5653: ** ^If the [threading mode] is Single-thread or Multi-thread then this
5654: ** routine returns a NULL pointer.
5655: */
5656: SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
5657:
5658: /*
5659: ** CAPI3REF: Low-Level Control Of Database Files
5660: **
5661: ** ^The [sqlite3_file_control()] interface makes a direct call to the
5662: ** xFileControl method for the [sqlite3_io_methods] object associated
5663: ** with a particular database identified by the second argument. ^The
5664: ** name of the database is "main" for the main database or "temp" for the
5665: ** TEMP database, or the name that appears after the AS keyword for
5666: ** databases that are added using the [ATTACH] SQL command.
5667: ** ^A NULL pointer can be used in place of "main" to refer to the
5668: ** main database file.
5669: ** ^The third and fourth parameters to this routine
5670: ** are passed directly through to the second and third parameters of
5671: ** the xFileControl method. ^The return value of the xFileControl
5672: ** method becomes the return value of this routine.
5673: **
5674: ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
5675: ** a pointer to the underlying [sqlite3_file] object to be written into
5676: ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
5677: ** case is a short-circuit path which does not actually invoke the
5678: ** underlying sqlite3_io_methods.xFileControl method.
5679: **
5680: ** ^If the second parameter (zDbName) does not match the name of any
5681: ** open database file, then SQLITE_ERROR is returned. ^This error
5682: ** code is not remembered and will not be recalled by [sqlite3_errcode()]
5683: ** or [sqlite3_errmsg()]. The underlying xFileControl method might
5684: ** also return SQLITE_ERROR. There is no way to distinguish between
5685: ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
5686: ** xFileControl method.
5687: **
5688: ** See also: [SQLITE_FCNTL_LOCKSTATE]
5689: */
5690: SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
5691:
5692: /*
5693: ** CAPI3REF: Testing Interface
5694: **
5695: ** ^The sqlite3_test_control() interface is used to read out internal
5696: ** state of SQLite and to inject faults into SQLite for testing
5697: ** purposes. ^The first parameter is an operation code that determines
5698: ** the number, meaning, and operation of all subsequent parameters.
5699: **
5700: ** This interface is not for use by applications. It exists solely
5701: ** for verifying the correct operation of the SQLite library. Depending
5702: ** on how the SQLite library is compiled, this interface might not exist.
5703: **
5704: ** The details of the operation codes, their meanings, the parameters
5705: ** they take, and what they do are all subject to change without notice.
5706: ** Unlike most of the SQLite API, this function is not guaranteed to
5707: ** operate consistently from one release to the next.
5708: */
5709: SQLITE_API int sqlite3_test_control(int op, ...);
5710:
5711: /*
5712: ** CAPI3REF: Testing Interface Operation Codes
5713: **
5714: ** These constants are the valid operation code parameters used
5715: ** as the first argument to [sqlite3_test_control()].
5716: **
5717: ** These parameters and their meanings are subject to change
5718: ** without notice. These values are for testing purposes only.
5719: ** Applications should not use any of these parameters or the
5720: ** [sqlite3_test_control()] interface.
5721: */
5722: #define SQLITE_TESTCTRL_FIRST 5
5723: #define SQLITE_TESTCTRL_PRNG_SAVE 5
5724: #define SQLITE_TESTCTRL_PRNG_RESTORE 6
5725: #define SQLITE_TESTCTRL_PRNG_RESET 7
5726: #define SQLITE_TESTCTRL_BITVEC_TEST 8
5727: #define SQLITE_TESTCTRL_FAULT_INSTALL 9
5728: #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
5729: #define SQLITE_TESTCTRL_PENDING_BYTE 11
5730: #define SQLITE_TESTCTRL_ASSERT 12
5731: #define SQLITE_TESTCTRL_ALWAYS 13
5732: #define SQLITE_TESTCTRL_RESERVE 14
5733: #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
5734: #define SQLITE_TESTCTRL_ISKEYWORD 16
5735: #define SQLITE_TESTCTRL_SCRATCHMALLOC 17
5736: #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
5737: #define SQLITE_TESTCTRL_EXPLAIN_STMT 19
5738: #define SQLITE_TESTCTRL_LAST 19
5739:
5740: /*
5741: ** CAPI3REF: SQLite Runtime Status
5742: **
5743: ** ^This interface is used to retrieve runtime status information
5744: ** about the performance of SQLite, and optionally to reset various
5745: ** highwater marks. ^The first argument is an integer code for
5746: ** the specific parameter to measure. ^(Recognized integer codes
5747: ** are of the form [status parameters | SQLITE_STATUS_...].)^
5748: ** ^The current value of the parameter is returned into *pCurrent.
5749: ** ^The highest recorded value is returned in *pHighwater. ^If the
5750: ** resetFlag is true, then the highest record value is reset after
5751: ** *pHighwater is written. ^(Some parameters do not record the highest
5752: ** value. For those parameters
5753: ** nothing is written into *pHighwater and the resetFlag is ignored.)^
5754: ** ^(Other parameters record only the highwater mark and not the current
5755: ** value. For these latter parameters nothing is written into *pCurrent.)^
5756: **
5757: ** ^The sqlite3_status() routine returns SQLITE_OK on success and a
5758: ** non-zero [error code] on failure.
5759: **
5760: ** This routine is threadsafe but is not atomic. This routine can be
5761: ** called while other threads are running the same or different SQLite
5762: ** interfaces. However the values returned in *pCurrent and
5763: ** *pHighwater reflect the status of SQLite at different points in time
5764: ** and it is possible that another thread might change the parameter
5765: ** in between the times when *pCurrent and *pHighwater are written.
5766: **
5767: ** See also: [sqlite3_db_status()]
5768: */
5769: SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
5770:
5771:
5772: /*
5773: ** CAPI3REF: Status Parameters
5774: ** KEYWORDS: {status parameters}
5775: **
5776: ** These integer constants designate various run-time status parameters
5777: ** that can be returned by [sqlite3_status()].
5778: **
5779: ** <dl>
5780: ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
5781: ** <dd>This parameter is the current amount of memory checked out
5782: ** using [sqlite3_malloc()], either directly or indirectly. The
5783: ** figure includes calls made to [sqlite3_malloc()] by the application
5784: ** and internal memory usage by the SQLite library. Scratch memory
5785: ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
5786: ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
5787: ** this parameter. The amount returned is the sum of the allocation
5788: ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
5789: **
5790: ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
5791: ** <dd>This parameter records the largest memory allocation request
5792: ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
5793: ** internal equivalents). Only the value returned in the
5794: ** *pHighwater parameter to [sqlite3_status()] is of interest.
5795: ** The value written into the *pCurrent parameter is undefined.</dd>)^
5796: **
5797: ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
5798: ** <dd>This parameter records the number of separate memory allocations
5799: ** currently checked out.</dd>)^
5800: **
5801: ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
5802: ** <dd>This parameter returns the number of pages used out of the
5803: ** [pagecache memory allocator] that was configured using
5804: ** [SQLITE_CONFIG_PAGECACHE]. The
5805: ** value returned is in pages, not in bytes.</dd>)^
5806: **
5807: ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
5808: ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
5809: ** <dd>This parameter returns the number of bytes of page cache
5810: ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
5811: ** buffer and where forced to overflow to [sqlite3_malloc()]. The
5812: ** returned value includes allocations that overflowed because they
5813: ** where too large (they were larger than the "sz" parameter to
5814: ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
5815: ** no space was left in the page cache.</dd>)^
5816: **
5817: ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
5818: ** <dd>This parameter records the largest memory allocation request
5819: ** handed to [pagecache memory allocator]. Only the value returned in the
5820: ** *pHighwater parameter to [sqlite3_status()] is of interest.
5821: ** The value written into the *pCurrent parameter is undefined.</dd>)^
5822: **
5823: ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
5824: ** <dd>This parameter returns the number of allocations used out of the
5825: ** [scratch memory allocator] configured using
5826: ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
5827: ** in bytes. Since a single thread may only have one scratch allocation
5828: ** outstanding at time, this parameter also reports the number of threads
5829: ** using scratch memory at the same time.</dd>)^
5830: **
5831: ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
5832: ** <dd>This parameter returns the number of bytes of scratch memory
5833: ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
5834: ** buffer and where forced to overflow to [sqlite3_malloc()]. The values
5835: ** returned include overflows because the requested allocation was too
5836: ** larger (that is, because the requested allocation was larger than the
5837: ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
5838: ** slots were available.
5839: ** </dd>)^
5840: **
5841: ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
5842: ** <dd>This parameter records the largest memory allocation request
5843: ** handed to [scratch memory allocator]. Only the value returned in the
5844: ** *pHighwater parameter to [sqlite3_status()] is of interest.
5845: ** The value written into the *pCurrent parameter is undefined.</dd>)^
5846: **
5847: ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
5848: ** <dd>This parameter records the deepest parser stack. It is only
5849: ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
5850: ** </dl>
5851: **
5852: ** New status parameters may be added from time to time.
5853: */
5854: #define SQLITE_STATUS_MEMORY_USED 0
5855: #define SQLITE_STATUS_PAGECACHE_USED 1
5856: #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
5857: #define SQLITE_STATUS_SCRATCH_USED 3
5858: #define SQLITE_STATUS_SCRATCH_OVERFLOW 4
5859: #define SQLITE_STATUS_MALLOC_SIZE 5
5860: #define SQLITE_STATUS_PARSER_STACK 6
5861: #define SQLITE_STATUS_PAGECACHE_SIZE 7
5862: #define SQLITE_STATUS_SCRATCH_SIZE 8
5863: #define SQLITE_STATUS_MALLOC_COUNT 9
5864:
5865: /*
5866: ** CAPI3REF: Database Connection Status
5867: **
5868: ** ^This interface is used to retrieve runtime status information
5869: ** about a single [database connection]. ^The first argument is the
5870: ** database connection object to be interrogated. ^The second argument
5871: ** is an integer constant, taken from the set of
5872: ** [SQLITE_DBSTATUS options], that
5873: ** determines the parameter to interrogate. The set of
5874: ** [SQLITE_DBSTATUS options] is likely
5875: ** to grow in future releases of SQLite.
5876: **
5877: ** ^The current value of the requested parameter is written into *pCur
5878: ** and the highest instantaneous value is written into *pHiwtr. ^If
5879: ** the resetFlg is true, then the highest instantaneous value is
5880: ** reset back down to the current value.
5881: **
5882: ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
5883: ** non-zero [error code] on failure.
5884: **
5885: ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
5886: */
5887: SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
5888:
5889: /*
5890: ** CAPI3REF: Status Parameters for database connections
5891: ** KEYWORDS: {SQLITE_DBSTATUS options}
5892: **
5893: ** These constants are the available integer "verbs" that can be passed as
5894: ** the second argument to the [sqlite3_db_status()] interface.
5895: **
5896: ** New verbs may be added in future releases of SQLite. Existing verbs
5897: ** might be discontinued. Applications should check the return code from
5898: ** [sqlite3_db_status()] to make sure that the call worked.
5899: ** The [sqlite3_db_status()] interface will return a non-zero error code
5900: ** if a discontinued or unsupported verb is invoked.
5901: **
5902: ** <dl>
5903: ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
5904: ** <dd>This parameter returns the number of lookaside memory slots currently
5905: ** checked out.</dd>)^
5906: **
5907: ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
5908: ** <dd>This parameter returns the number malloc attempts that were
5909: ** satisfied using lookaside memory. Only the high-water value is meaningful;
5910: ** the current value is always zero.)^
5911: **
5912: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
5913: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
5914: ** <dd>This parameter returns the number malloc attempts that might have
5915: ** been satisfied using lookaside memory but failed due to the amount of
5916: ** memory requested being larger than the lookaside slot size.
5917: ** Only the high-water value is meaningful;
5918: ** the current value is always zero.)^
5919: **
5920: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
5921: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
5922: ** <dd>This parameter returns the number malloc attempts that might have
5923: ** been satisfied using lookaside memory but failed due to all lookaside
5924: ** memory already being in use.
5925: ** Only the high-water value is meaningful;
5926: ** the current value is always zero.)^
5927: **
5928: ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
5929: ** <dd>This parameter returns the approximate number of of bytes of heap
5930: ** memory used by all pager caches associated with the database connection.)^
5931: ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
5932: **
5933: ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
5934: ** <dd>This parameter returns the approximate number of of bytes of heap
5935: ** memory used to store the schema for all databases associated
5936: ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
5937: ** ^The full amount of memory used by the schemas is reported, even if the
5938: ** schema memory is shared with other database connections due to
5939: ** [shared cache mode] being enabled.
5940: ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
5941: **
5942: ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
5943: ** <dd>This parameter returns the approximate number of of bytes of heap
5944: ** and lookaside memory used by all prepared statements associated with
5945: ** the database connection.)^
5946: ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
5947: ** </dd>
5948: **
5949: ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
5950: ** <dd>This parameter returns the number of pager cache hits that have
5951: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
5952: ** is always 0.
5953: ** </dd>
5954: **
5955: ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
5956: ** <dd>This parameter returns the number of pager cache misses that have
5957: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
5958: ** is always 0.
5959: ** </dd>
5960: ** </dl>
5961: */
5962: #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
5963: #define SQLITE_DBSTATUS_CACHE_USED 1
5964: #define SQLITE_DBSTATUS_SCHEMA_USED 2
5965: #define SQLITE_DBSTATUS_STMT_USED 3
5966: #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
5967: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
5968: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
5969: #define SQLITE_DBSTATUS_CACHE_HIT 7
5970: #define SQLITE_DBSTATUS_CACHE_MISS 8
5971: #define SQLITE_DBSTATUS_MAX 8 /* Largest defined DBSTATUS */
5972:
5973:
5974: /*
5975: ** CAPI3REF: Prepared Statement Status
5976: **
5977: ** ^(Each prepared statement maintains various
5978: ** [SQLITE_STMTSTATUS counters] that measure the number
5979: ** of times it has performed specific operations.)^ These counters can
5980: ** be used to monitor the performance characteristics of the prepared
5981: ** statements. For example, if the number of table steps greatly exceeds
5982: ** the number of table searches or result rows, that would tend to indicate
5983: ** that the prepared statement is using a full table scan rather than
5984: ** an index.
5985: **
5986: ** ^(This interface is used to retrieve and reset counter values from
5987: ** a [prepared statement]. The first argument is the prepared statement
5988: ** object to be interrogated. The second argument
5989: ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
5990: ** to be interrogated.)^
5991: ** ^The current value of the requested counter is returned.
5992: ** ^If the resetFlg is true, then the counter is reset to zero after this
5993: ** interface call returns.
5994: **
5995: ** See also: [sqlite3_status()] and [sqlite3_db_status()].
5996: */
5997: SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
5998:
5999: /*
6000: ** CAPI3REF: Status Parameters for prepared statements
6001: ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
6002: **
6003: ** These preprocessor macros define integer codes that name counter
6004: ** values associated with the [sqlite3_stmt_status()] interface.
6005: ** The meanings of the various counters are as follows:
6006: **
6007: ** <dl>
6008: ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
6009: ** <dd>^This is the number of times that SQLite has stepped forward in
6010: ** a table as part of a full table scan. Large numbers for this counter
6011: ** may indicate opportunities for performance improvement through
6012: ** careful use of indices.</dd>
6013: **
6014: ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
6015: ** <dd>^This is the number of sort operations that have occurred.
6016: ** A non-zero value in this counter may indicate an opportunity to
6017: ** improvement performance through careful use of indices.</dd>
6018: **
6019: ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
6020: ** <dd>^This is the number of rows inserted into transient indices that
6021: ** were created automatically in order to help joins run faster.
6022: ** A non-zero value in this counter may indicate an opportunity to
6023: ** improvement performance by adding permanent indices that do not
6024: ** need to be reinitialized each time the statement is run.</dd>
6025: ** </dl>
6026: */
6027: #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
6028: #define SQLITE_STMTSTATUS_SORT 2
6029: #define SQLITE_STMTSTATUS_AUTOINDEX 3
6030:
6031: /*
6032: ** CAPI3REF: Custom Page Cache Object
6033: **
6034: ** The sqlite3_pcache type is opaque. It is implemented by
6035: ** the pluggable module. The SQLite core has no knowledge of
6036: ** its size or internal structure and never deals with the
6037: ** sqlite3_pcache object except by holding and passing pointers
6038: ** to the object.
6039: **
6040: ** See [sqlite3_pcache_methods2] for additional information.
6041: */
6042: typedef struct sqlite3_pcache sqlite3_pcache;
6043:
6044: /*
6045: ** CAPI3REF: Custom Page Cache Object
6046: **
6047: ** The sqlite3_pcache_page object represents a single page in the
6048: ** page cache. The page cache will allocate instances of this
6049: ** object. Various methods of the page cache use pointers to instances
6050: ** of this object as parameters or as their return value.
6051: **
6052: ** See [sqlite3_pcache_methods2] for additional information.
6053: */
6054: typedef struct sqlite3_pcache_page sqlite3_pcache_page;
6055: struct sqlite3_pcache_page {
6056: void *pBuf; /* The content of the page */
6057: void *pExtra; /* Extra information associated with the page */
6058: };
6059:
6060: /*
6061: ** CAPI3REF: Application Defined Page Cache.
6062: ** KEYWORDS: {page cache}
6063: **
6064: ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
6065: ** register an alternative page cache implementation by passing in an
6066: ** instance of the sqlite3_pcache_methods2 structure.)^
6067: ** In many applications, most of the heap memory allocated by
6068: ** SQLite is used for the page cache.
6069: ** By implementing a
6070: ** custom page cache using this API, an application can better control
6071: ** the amount of memory consumed by SQLite, the way in which
6072: ** that memory is allocated and released, and the policies used to
6073: ** determine exactly which parts of a database file are cached and for
6074: ** how long.
6075: **
6076: ** The alternative page cache mechanism is an
6077: ** extreme measure that is only needed by the most demanding applications.
6078: ** The built-in page cache is recommended for most uses.
6079: **
6080: ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
6081: ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
6082: ** the application may discard the parameter after the call to
6083: ** [sqlite3_config()] returns.)^
6084: **
6085: ** [[the xInit() page cache method]]
6086: ** ^(The xInit() method is called once for each effective
6087: ** call to [sqlite3_initialize()])^
6088: ** (usually only once during the lifetime of the process). ^(The xInit()
6089: ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
6090: ** The intent of the xInit() method is to set up global data structures
6091: ** required by the custom page cache implementation.
6092: ** ^(If the xInit() method is NULL, then the
6093: ** built-in default page cache is used instead of the application defined
6094: ** page cache.)^
6095: **
6096: ** [[the xShutdown() page cache method]]
6097: ** ^The xShutdown() method is called by [sqlite3_shutdown()].
6098: ** It can be used to clean up
6099: ** any outstanding resources before process shutdown, if required.
6100: ** ^The xShutdown() method may be NULL.
6101: **
6102: ** ^SQLite automatically serializes calls to the xInit method,
6103: ** so the xInit method need not be threadsafe. ^The
6104: ** xShutdown method is only called from [sqlite3_shutdown()] so it does
6105: ** not need to be threadsafe either. All other methods must be threadsafe
6106: ** in multithreaded applications.
6107: **
6108: ** ^SQLite will never invoke xInit() more than once without an intervening
6109: ** call to xShutdown().
6110: **
6111: ** [[the xCreate() page cache methods]]
6112: ** ^SQLite invokes the xCreate() method to construct a new cache instance.
6113: ** SQLite will typically create one cache instance for each open database file,
6114: ** though this is not guaranteed. ^The
6115: ** first parameter, szPage, is the size in bytes of the pages that must
6116: ** be allocated by the cache. ^szPage will always a power of two. ^The
6117: ** second parameter szExtra is a number of bytes of extra storage
6118: ** associated with each page cache entry. ^The szExtra parameter will
6119: ** a number less than 250. SQLite will use the
6120: ** extra szExtra bytes on each page to store metadata about the underlying
6121: ** database page on disk. The value passed into szExtra depends
6122: ** on the SQLite version, the target platform, and how SQLite was compiled.
6123: ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
6124: ** created will be used to cache database pages of a file stored on disk, or
6125: ** false if it is used for an in-memory database. The cache implementation
6126: ** does not have to do anything special based with the value of bPurgeable;
6127: ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
6128: ** never invoke xUnpin() except to deliberately delete a page.
6129: ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
6130: ** false will always have the "discard" flag set to true.
6131: ** ^Hence, a cache created with bPurgeable false will
6132: ** never contain any unpinned pages.
6133: **
6134: ** [[the xCachesize() page cache method]]
6135: ** ^(The xCachesize() method may be called at any time by SQLite to set the
6136: ** suggested maximum cache-size (number of pages stored by) the cache
6137: ** instance passed as the first argument. This is the value configured using
6138: ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
6139: ** parameter, the implementation is not required to do anything with this
6140: ** value; it is advisory only.
6141: **
6142: ** [[the xPagecount() page cache methods]]
6143: ** The xPagecount() method must return the number of pages currently
6144: ** stored in the cache, both pinned and unpinned.
6145: **
6146: ** [[the xFetch() page cache methods]]
6147: ** The xFetch() method locates a page in the cache and returns a pointer to
6148: ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
6149: ** The pBuf element of the returned sqlite3_pcache_page object will be a
6150: ** pointer to a buffer of szPage bytes used to store the content of a
6151: ** single database page. The pExtra element of sqlite3_pcache_page will be
6152: ** a pointer to the szExtra bytes of extra storage that SQLite has requested
6153: ** for each entry in the page cache.
6154: **
6155: ** The page to be fetched is determined by the key. ^The minimum key value
6156: ** is 1. After it has been retrieved using xFetch, the page is considered
6157: ** to be "pinned".
6158: **
6159: ** If the requested page is already in the page cache, then the page cache
6160: ** implementation must return a pointer to the page buffer with its content
6161: ** intact. If the requested page is not already in the cache, then the
6162: ** cache implementation should use the value of the createFlag
6163: ** parameter to help it determined what action to take:
6164: **
6165: ** <table border=1 width=85% align=center>
6166: ** <tr><th> createFlag <th> Behaviour when page is not already in cache
6167: ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
6168: ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
6169: ** Otherwise return NULL.
6170: ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
6171: ** NULL if allocating a new page is effectively impossible.
6172: ** </table>
6173: **
6174: ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
6175: ** will only use a createFlag of 2 after a prior call with a createFlag of 1
6176: ** failed.)^ In between the to xFetch() calls, SQLite may
6177: ** attempt to unpin one or more cache pages by spilling the content of
6178: ** pinned pages to disk and synching the operating system disk cache.
6179: **
6180: ** [[the xUnpin() page cache method]]
6181: ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
6182: ** as its second argument. If the third parameter, discard, is non-zero,
6183: ** then the page must be evicted from the cache.
6184: ** ^If the discard parameter is
6185: ** zero, then the page may be discarded or retained at the discretion of
6186: ** page cache implementation. ^The page cache implementation
6187: ** may choose to evict unpinned pages at any time.
6188: **
6189: ** The cache must not perform any reference counting. A single
6190: ** call to xUnpin() unpins the page regardless of the number of prior calls
6191: ** to xFetch().
6192: **
6193: ** [[the xRekey() page cache methods]]
6194: ** The xRekey() method is used to change the key value associated with the
6195: ** page passed as the second argument. If the cache
6196: ** previously contains an entry associated with newKey, it must be
6197: ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
6198: ** to be pinned.
6199: **
6200: ** When SQLite calls the xTruncate() method, the cache must discard all
6201: ** existing cache entries with page numbers (keys) greater than or equal
6202: ** to the value of the iLimit parameter passed to xTruncate(). If any
6203: ** of these pages are pinned, they are implicitly unpinned, meaning that
6204: ** they can be safely discarded.
6205: **
6206: ** [[the xDestroy() page cache method]]
6207: ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
6208: ** All resources associated with the specified cache should be freed. ^After
6209: ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
6210: ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
6211: ** functions.
6212: **
6213: ** [[the xShrink() page cache method]]
6214: ** ^SQLite invokes the xShrink() method when it wants the page cache to
6215: ** free up as much of heap memory as possible. The page cache implementation
6216: ** is not obligated to free any memory, but well-behaved implementations should
6217: ** do their best.
6218: */
6219: typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
6220: struct sqlite3_pcache_methods2 {
6221: int iVersion;
6222: void *pArg;
6223: int (*xInit)(void*);
6224: void (*xShutdown)(void*);
6225: sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
6226: void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6227: int (*xPagecount)(sqlite3_pcache*);
6228: sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6229: void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
6230: void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
6231: unsigned oldKey, unsigned newKey);
6232: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6233: void (*xDestroy)(sqlite3_pcache*);
6234: void (*xShrink)(sqlite3_pcache*);
6235: };
6236:
6237: /*
6238: ** This is the obsolete pcache_methods object that has now been replaced
6239: ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
6240: ** retained in the header file for backwards compatibility only.
6241: */
6242: typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
6243: struct sqlite3_pcache_methods {
6244: void *pArg;
6245: int (*xInit)(void*);
6246: void (*xShutdown)(void*);
6247: sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
6248: void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6249: int (*xPagecount)(sqlite3_pcache*);
6250: void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6251: void (*xUnpin)(sqlite3_pcache*, void*, int discard);
6252: void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
6253: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6254: void (*xDestroy)(sqlite3_pcache*);
6255: };
6256:
6257:
6258: /*
6259: ** CAPI3REF: Online Backup Object
6260: **
6261: ** The sqlite3_backup object records state information about an ongoing
6262: ** online backup operation. ^The sqlite3_backup object is created by
6263: ** a call to [sqlite3_backup_init()] and is destroyed by a call to
6264: ** [sqlite3_backup_finish()].
6265: **
6266: ** See Also: [Using the SQLite Online Backup API]
6267: */
6268: typedef struct sqlite3_backup sqlite3_backup;
6269:
6270: /*
6271: ** CAPI3REF: Online Backup API.
6272: **
6273: ** The backup API copies the content of one database into another.
6274: ** It is useful either for creating backups of databases or
6275: ** for copying in-memory databases to or from persistent files.
6276: **
6277: ** See Also: [Using the SQLite Online Backup API]
6278: **
6279: ** ^SQLite holds a write transaction open on the destination database file
6280: ** for the duration of the backup operation.
6281: ** ^The source database is read-locked only while it is being read;
6282: ** it is not locked continuously for the entire backup operation.
6283: ** ^Thus, the backup may be performed on a live source database without
6284: ** preventing other database connections from
6285: ** reading or writing to the source database while the backup is underway.
6286: **
6287: ** ^(To perform a backup operation:
6288: ** <ol>
6289: ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
6290: ** backup,
6291: ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
6292: ** the data between the two databases, and finally
6293: ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
6294: ** associated with the backup operation.
6295: ** </ol>)^
6296: ** There should be exactly one call to sqlite3_backup_finish() for each
6297: ** successful call to sqlite3_backup_init().
6298: **
6299: ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
6300: **
6301: ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
6302: ** [database connection] associated with the destination database
6303: ** and the database name, respectively.
6304: ** ^The database name is "main" for the main database, "temp" for the
6305: ** temporary database, or the name specified after the AS keyword in
6306: ** an [ATTACH] statement for an attached database.
6307: ** ^The S and M arguments passed to
6308: ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
6309: ** and database name of the source database, respectively.
6310: ** ^The source and destination [database connections] (parameters S and D)
6311: ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
6312: ** an error.
6313: **
6314: ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
6315: ** returned and an error code and error message are stored in the
6316: ** destination [database connection] D.
6317: ** ^The error code and message for the failed call to sqlite3_backup_init()
6318: ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
6319: ** [sqlite3_errmsg16()] functions.
6320: ** ^A successful call to sqlite3_backup_init() returns a pointer to an
6321: ** [sqlite3_backup] object.
6322: ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
6323: ** sqlite3_backup_finish() functions to perform the specified backup
6324: ** operation.
6325: **
6326: ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
6327: **
6328: ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
6329: ** the source and destination databases specified by [sqlite3_backup] object B.
6330: ** ^If N is negative, all remaining source pages are copied.
6331: ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
6332: ** are still more pages to be copied, then the function returns [SQLITE_OK].
6333: ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
6334: ** from source to destination, then it returns [SQLITE_DONE].
6335: ** ^If an error occurs while running sqlite3_backup_step(B,N),
6336: ** then an [error code] is returned. ^As well as [SQLITE_OK] and
6337: ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
6338: ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
6339: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
6340: **
6341: ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
6342: ** <ol>
6343: ** <li> the destination database was opened read-only, or
6344: ** <li> the destination database is using write-ahead-log journaling
6345: ** and the destination and source page sizes differ, or
6346: ** <li> the destination database is an in-memory database and the
6347: ** destination and source page sizes differ.
6348: ** </ol>)^
6349: **
6350: ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
6351: ** the [sqlite3_busy_handler | busy-handler function]
6352: ** is invoked (if one is specified). ^If the
6353: ** busy-handler returns non-zero before the lock is available, then
6354: ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
6355: ** sqlite3_backup_step() can be retried later. ^If the source
6356: ** [database connection]
6357: ** is being used to write to the source database when sqlite3_backup_step()
6358: ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
6359: ** case the call to sqlite3_backup_step() can be retried later on. ^(If
6360: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
6361: ** [SQLITE_READONLY] is returned, then
6362: ** there is no point in retrying the call to sqlite3_backup_step(). These
6363: ** errors are considered fatal.)^ The application must accept
6364: ** that the backup operation has failed and pass the backup operation handle
6365: ** to the sqlite3_backup_finish() to release associated resources.
6366: **
6367: ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
6368: ** on the destination file. ^The exclusive lock is not released until either
6369: ** sqlite3_backup_finish() is called or the backup operation is complete
6370: ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
6371: ** sqlite3_backup_step() obtains a [shared lock] on the source database that
6372: ** lasts for the duration of the sqlite3_backup_step() call.
6373: ** ^Because the source database is not locked between calls to
6374: ** sqlite3_backup_step(), the source database may be modified mid-way
6375: ** through the backup process. ^If the source database is modified by an
6376: ** external process or via a database connection other than the one being
6377: ** used by the backup operation, then the backup will be automatically
6378: ** restarted by the next call to sqlite3_backup_step(). ^If the source
6379: ** database is modified by the using the same database connection as is used
6380: ** by the backup operation, then the backup database is automatically
6381: ** updated at the same time.
6382: **
6383: ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
6384: **
6385: ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
6386: ** application wishes to abandon the backup operation, the application
6387: ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
6388: ** ^The sqlite3_backup_finish() interfaces releases all
6389: ** resources associated with the [sqlite3_backup] object.
6390: ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
6391: ** active write-transaction on the destination database is rolled back.
6392: ** The [sqlite3_backup] object is invalid
6393: ** and may not be used following a call to sqlite3_backup_finish().
6394: **
6395: ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
6396: ** sqlite3_backup_step() errors occurred, regardless or whether or not
6397: ** sqlite3_backup_step() completed.
6398: ** ^If an out-of-memory condition or IO error occurred during any prior
6399: ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
6400: ** sqlite3_backup_finish() returns the corresponding [error code].
6401: **
6402: ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
6403: ** is not a permanent error and does not affect the return value of
6404: ** sqlite3_backup_finish().
6405: **
6406: ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
6407: ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
6408: **
6409: ** ^Each call to sqlite3_backup_step() sets two values inside
6410: ** the [sqlite3_backup] object: the number of pages still to be backed
6411: ** up and the total number of pages in the source database file.
6412: ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
6413: ** retrieve these two values, respectively.
6414: **
6415: ** ^The values returned by these functions are only updated by
6416: ** sqlite3_backup_step(). ^If the source database is modified during a backup
6417: ** operation, then the values are not updated to account for any extra
6418: ** pages that need to be updated or the size of the source database file
6419: ** changing.
6420: **
6421: ** <b>Concurrent Usage of Database Handles</b>
6422: **
6423: ** ^The source [database connection] may be used by the application for other
6424: ** purposes while a backup operation is underway or being initialized.
6425: ** ^If SQLite is compiled and configured to support threadsafe database
6426: ** connections, then the source database connection may be used concurrently
6427: ** from within other threads.
6428: **
6429: ** However, the application must guarantee that the destination
6430: ** [database connection] is not passed to any other API (by any thread) after
6431: ** sqlite3_backup_init() is called and before the corresponding call to
6432: ** sqlite3_backup_finish(). SQLite does not currently check to see
6433: ** if the application incorrectly accesses the destination [database connection]
6434: ** and so no error code is reported, but the operations may malfunction
6435: ** nevertheless. Use of the destination database connection while a
6436: ** backup is in progress might also also cause a mutex deadlock.
6437: **
6438: ** If running in [shared cache mode], the application must
6439: ** guarantee that the shared cache used by the destination database
6440: ** is not accessed while the backup is running. In practice this means
6441: ** that the application must guarantee that the disk file being
6442: ** backed up to is not accessed by any connection within the process,
6443: ** not just the specific connection that was passed to sqlite3_backup_init().
6444: **
6445: ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
6446: ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
6447: ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
6448: ** APIs are not strictly speaking threadsafe. If they are invoked at the
6449: ** same time as another thread is invoking sqlite3_backup_step() it is
6450: ** possible that they return invalid values.
6451: */
6452: SQLITE_API sqlite3_backup *sqlite3_backup_init(
6453: sqlite3 *pDest, /* Destination database handle */
6454: const char *zDestName, /* Destination database name */
6455: sqlite3 *pSource, /* Source database handle */
6456: const char *zSourceName /* Source database name */
6457: );
6458: SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
6459: SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
6460: SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
6461: SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
6462:
6463: /*
6464: ** CAPI3REF: Unlock Notification
6465: **
6466: ** ^When running in shared-cache mode, a database operation may fail with
6467: ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
6468: ** individual tables within the shared-cache cannot be obtained. See
6469: ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
6470: ** ^This API may be used to register a callback that SQLite will invoke
6471: ** when the connection currently holding the required lock relinquishes it.
6472: ** ^This API is only available if the library was compiled with the
6473: ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
6474: **
6475: ** See Also: [Using the SQLite Unlock Notification Feature].
6476: **
6477: ** ^Shared-cache locks are released when a database connection concludes
6478: ** its current transaction, either by committing it or rolling it back.
6479: **
6480: ** ^When a connection (known as the blocked connection) fails to obtain a
6481: ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
6482: ** identity of the database connection (the blocking connection) that
6483: ** has locked the required resource is stored internally. ^After an
6484: ** application receives an SQLITE_LOCKED error, it may call the
6485: ** sqlite3_unlock_notify() method with the blocked connection handle as
6486: ** the first argument to register for a callback that will be invoked
6487: ** when the blocking connections current transaction is concluded. ^The
6488: ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
6489: ** call that concludes the blocking connections transaction.
6490: **
6491: ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
6492: ** there is a chance that the blocking connection will have already
6493: ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
6494: ** If this happens, then the specified callback is invoked immediately,
6495: ** from within the call to sqlite3_unlock_notify().)^
6496: **
6497: ** ^If the blocked connection is attempting to obtain a write-lock on a
6498: ** shared-cache table, and more than one other connection currently holds
6499: ** a read-lock on the same table, then SQLite arbitrarily selects one of
6500: ** the other connections to use as the blocking connection.
6501: **
6502: ** ^(There may be at most one unlock-notify callback registered by a
6503: ** blocked connection. If sqlite3_unlock_notify() is called when the
6504: ** blocked connection already has a registered unlock-notify callback,
6505: ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
6506: ** called with a NULL pointer as its second argument, then any existing
6507: ** unlock-notify callback is canceled. ^The blocked connections
6508: ** unlock-notify callback may also be canceled by closing the blocked
6509: ** connection using [sqlite3_close()].
6510: **
6511: ** The unlock-notify callback is not reentrant. If an application invokes
6512: ** any sqlite3_xxx API functions from within an unlock-notify callback, a
6513: ** crash or deadlock may be the result.
6514: **
6515: ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
6516: ** returns SQLITE_OK.
6517: **
6518: ** <b>Callback Invocation Details</b>
6519: **
6520: ** When an unlock-notify callback is registered, the application provides a
6521: ** single void* pointer that is passed to the callback when it is invoked.
6522: ** However, the signature of the callback function allows SQLite to pass
6523: ** it an array of void* context pointers. The first argument passed to
6524: ** an unlock-notify callback is a pointer to an array of void* pointers,
6525: ** and the second is the number of entries in the array.
6526: **
6527: ** When a blocking connections transaction is concluded, there may be
6528: ** more than one blocked connection that has registered for an unlock-notify
6529: ** callback. ^If two or more such blocked connections have specified the
6530: ** same callback function, then instead of invoking the callback function
6531: ** multiple times, it is invoked once with the set of void* context pointers
6532: ** specified by the blocked connections bundled together into an array.
6533: ** This gives the application an opportunity to prioritize any actions
6534: ** related to the set of unblocked database connections.
6535: **
6536: ** <b>Deadlock Detection</b>
6537: **
6538: ** Assuming that after registering for an unlock-notify callback a
6539: ** database waits for the callback to be issued before taking any further
6540: ** action (a reasonable assumption), then using this API may cause the
6541: ** application to deadlock. For example, if connection X is waiting for
6542: ** connection Y's transaction to be concluded, and similarly connection
6543: ** Y is waiting on connection X's transaction, then neither connection
6544: ** will proceed and the system may remain deadlocked indefinitely.
6545: **
6546: ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
6547: ** detection. ^If a given call to sqlite3_unlock_notify() would put the
6548: ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
6549: ** unlock-notify callback is registered. The system is said to be in
6550: ** a deadlocked state if connection A has registered for an unlock-notify
6551: ** callback on the conclusion of connection B's transaction, and connection
6552: ** B has itself registered for an unlock-notify callback when connection
6553: ** A's transaction is concluded. ^Indirect deadlock is also detected, so
6554: ** the system is also considered to be deadlocked if connection B has
6555: ** registered for an unlock-notify callback on the conclusion of connection
6556: ** C's transaction, where connection C is waiting on connection A. ^Any
6557: ** number of levels of indirection are allowed.
6558: **
6559: ** <b>The "DROP TABLE" Exception</b>
6560: **
6561: ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
6562: ** always appropriate to call sqlite3_unlock_notify(). There is however,
6563: ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
6564: ** SQLite checks if there are any currently executing SELECT statements
6565: ** that belong to the same connection. If there are, SQLITE_LOCKED is
6566: ** returned. In this case there is no "blocking connection", so invoking
6567: ** sqlite3_unlock_notify() results in the unlock-notify callback being
6568: ** invoked immediately. If the application then re-attempts the "DROP TABLE"
6569: ** or "DROP INDEX" query, an infinite loop might be the result.
6570: **
6571: ** One way around this problem is to check the extended error code returned
6572: ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
6573: ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
6574: ** the special "DROP TABLE/INDEX" case, the extended error code is just
6575: ** SQLITE_LOCKED.)^
6576: */
6577: SQLITE_API int sqlite3_unlock_notify(
6578: sqlite3 *pBlocked, /* Waiting connection */
6579: void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
6580: void *pNotifyArg /* Argument to pass to xNotify */
6581: );
6582:
6583:
6584: /*
6585: ** CAPI3REF: String Comparison
6586: **
6587: ** ^The [sqlite3_strnicmp()] API allows applications and extensions to
6588: ** compare the contents of two buffers containing UTF-8 strings in a
6589: ** case-independent fashion, using the same definition of case independence
6590: ** that SQLite uses internally when comparing identifiers.
6591: */
6592: SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
6593:
6594: /*
6595: ** CAPI3REF: Error Logging Interface
6596: **
6597: ** ^The [sqlite3_log()] interface writes a message into the error log
6598: ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
6599: ** ^If logging is enabled, the zFormat string and subsequent arguments are
6600: ** used with [sqlite3_snprintf()] to generate the final output string.
6601: **
6602: ** The sqlite3_log() interface is intended for use by extensions such as
6603: ** virtual tables, collating functions, and SQL functions. While there is
6604: ** nothing to prevent an application from calling sqlite3_log(), doing so
6605: ** is considered bad form.
6606: **
6607: ** The zFormat string must not be NULL.
6608: **
6609: ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
6610: ** will not use dynamically allocated memory. The log message is stored in
6611: ** a fixed-length buffer on the stack. If the log message is longer than
6612: ** a few hundred characters, it will be truncated to the length of the
6613: ** buffer.
6614: */
6615: SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
6616:
6617: /*
6618: ** CAPI3REF: Write-Ahead Log Commit Hook
6619: **
6620: ** ^The [sqlite3_wal_hook()] function is used to register a callback that
6621: ** will be invoked each time a database connection commits data to a
6622: ** [write-ahead log] (i.e. whenever a transaction is committed in
6623: ** [journal_mode | journal_mode=WAL mode]).
6624: **
6625: ** ^The callback is invoked by SQLite after the commit has taken place and
6626: ** the associated write-lock on the database released, so the implementation
6627: ** may read, write or [checkpoint] the database as required.
6628: **
6629: ** ^The first parameter passed to the callback function when it is invoked
6630: ** is a copy of the third parameter passed to sqlite3_wal_hook() when
6631: ** registering the callback. ^The second is a copy of the database handle.
6632: ** ^The third parameter is the name of the database that was written to -
6633: ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
6634: ** is the number of pages currently in the write-ahead log file,
6635: ** including those that were just committed.
6636: **
6637: ** The callback function should normally return [SQLITE_OK]. ^If an error
6638: ** code is returned, that error will propagate back up through the
6639: ** SQLite code base to cause the statement that provoked the callback
6640: ** to report an error, though the commit will have still occurred. If the
6641: ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
6642: ** that does not correspond to any valid SQLite error code, the results
6643: ** are undefined.
6644: **
6645: ** A single database handle may have at most a single write-ahead log callback
6646: ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
6647: ** previously registered write-ahead log callback. ^Note that the
6648: ** [sqlite3_wal_autocheckpoint()] interface and the
6649: ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
6650: ** those overwrite any prior [sqlite3_wal_hook()] settings.
6651: */
6652: SQLITE_API void *sqlite3_wal_hook(
6653: sqlite3*,
6654: int(*)(void *,sqlite3*,const char*,int),
6655: void*
6656: );
6657:
6658: /*
6659: ** CAPI3REF: Configure an auto-checkpoint
6660: **
6661: ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
6662: ** [sqlite3_wal_hook()] that causes any database on [database connection] D
6663: ** to automatically [checkpoint]
6664: ** after committing a transaction if there are N or
6665: ** more frames in the [write-ahead log] file. ^Passing zero or
6666: ** a negative value as the nFrame parameter disables automatic
6667: ** checkpoints entirely.
6668: **
6669: ** ^The callback registered by this function replaces any existing callback
6670: ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
6671: ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
6672: ** configured by this function.
6673: **
6674: ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
6675: ** from SQL.
6676: **
6677: ** ^Every new [database connection] defaults to having the auto-checkpoint
6678: ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
6679: ** pages. The use of this interface
6680: ** is only necessary if the default setting is found to be suboptimal
6681: ** for a particular application.
6682: */
6683: SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
6684:
6685: /*
6686: ** CAPI3REF: Checkpoint a database
6687: **
6688: ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
6689: ** on [database connection] D to be [checkpointed]. ^If X is NULL or an
6690: ** empty string, then a checkpoint is run on all databases of
6691: ** connection D. ^If the database connection D is not in
6692: ** [WAL | write-ahead log mode] then this interface is a harmless no-op.
6693: **
6694: ** ^The [wal_checkpoint pragma] can be used to invoke this interface
6695: ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the
6696: ** [wal_autocheckpoint pragma] can be used to cause this interface to be
6697: ** run whenever the WAL reaches a certain size threshold.
6698: **
6699: ** See also: [sqlite3_wal_checkpoint_v2()]
6700: */
6701: SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
6702:
6703: /*
6704: ** CAPI3REF: Checkpoint a database
6705: **
6706: ** Run a checkpoint operation on WAL database zDb attached to database
6707: ** handle db. The specific operation is determined by the value of the
6708: ** eMode parameter:
6709: **
6710: ** <dl>
6711: ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
6712: ** Checkpoint as many frames as possible without waiting for any database
6713: ** readers or writers to finish. Sync the db file if all frames in the log
6714: ** are checkpointed. This mode is the same as calling
6715: ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
6716: **
6717: ** <dt>SQLITE_CHECKPOINT_FULL<dd>
6718: ** This mode blocks (calls the busy-handler callback) until there is no
6719: ** database writer and all readers are reading from the most recent database
6720: ** snapshot. It then checkpoints all frames in the log file and syncs the
6721: ** database file. This call blocks database writers while it is running,
6722: ** but not database readers.
6723: **
6724: ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
6725: ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
6726: ** checkpointing the log file it blocks (calls the busy-handler callback)
6727: ** until all readers are reading from the database file only. This ensures
6728: ** that the next client to write to the database file restarts the log file
6729: ** from the beginning. This call blocks database writers while it is running,
6730: ** but not database readers.
6731: ** </dl>
6732: **
6733: ** If pnLog is not NULL, then *pnLog is set to the total number of frames in
6734: ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
6735: ** the total number of checkpointed frames (including any that were already
6736: ** checkpointed when this function is called). *pnLog and *pnCkpt may be
6737: ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
6738: ** If no values are available because of an error, they are both set to -1
6739: ** before returning to communicate this to the caller.
6740: **
6741: ** All calls obtain an exclusive "checkpoint" lock on the database file. If
6742: ** any other process is running a checkpoint operation at the same time, the
6743: ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
6744: ** busy-handler configured, it will not be invoked in this case.
6745: **
6746: ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
6747: ** "writer" lock on the database file. If the writer lock cannot be obtained
6748: ** immediately, and a busy-handler is configured, it is invoked and the writer
6749: ** lock retried until either the busy-handler returns 0 or the lock is
6750: ** successfully obtained. The busy-handler is also invoked while waiting for
6751: ** database readers as described above. If the busy-handler returns 0 before
6752: ** the writer lock is obtained or while waiting for database readers, the
6753: ** checkpoint operation proceeds from that point in the same way as
6754: ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
6755: ** without blocking any further. SQLITE_BUSY is returned in this case.
6756: **
6757: ** If parameter zDb is NULL or points to a zero length string, then the
6758: ** specified operation is attempted on all WAL databases. In this case the
6759: ** values written to output parameters *pnLog and *pnCkpt are undefined. If
6760: ** an SQLITE_BUSY error is encountered when processing one or more of the
6761: ** attached WAL databases, the operation is still attempted on any remaining
6762: ** attached databases and SQLITE_BUSY is returned to the caller. If any other
6763: ** error occurs while processing an attached database, processing is abandoned
6764: ** and the error code returned to the caller immediately. If no error
6765: ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
6766: ** databases, SQLITE_OK is returned.
6767: **
6768: ** If database zDb is the name of an attached database that is not in WAL
6769: ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
6770: ** zDb is not NULL (or a zero length string) and is not the name of any
6771: ** attached database, SQLITE_ERROR is returned to the caller.
6772: */
6773: SQLITE_API int sqlite3_wal_checkpoint_v2(
6774: sqlite3 *db, /* Database handle */
6775: const char *zDb, /* Name of attached database (or NULL) */
6776: int eMode, /* SQLITE_CHECKPOINT_* value */
6777: int *pnLog, /* OUT: Size of WAL log in frames */
6778: int *pnCkpt /* OUT: Total number of frames checkpointed */
6779: );
6780:
6781: /*
6782: ** CAPI3REF: Checkpoint operation parameters
6783: **
6784: ** These constants can be used as the 3rd parameter to
6785: ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()]
6786: ** documentation for additional information about the meaning and use of
6787: ** each of these values.
6788: */
6789: #define SQLITE_CHECKPOINT_PASSIVE 0
6790: #define SQLITE_CHECKPOINT_FULL 1
6791: #define SQLITE_CHECKPOINT_RESTART 2
6792:
6793: /*
6794: ** CAPI3REF: Virtual Table Interface Configuration
6795: **
6796: ** This function may be called by either the [xConnect] or [xCreate] method
6797: ** of a [virtual table] implementation to configure
6798: ** various facets of the virtual table interface.
6799: **
6800: ** If this interface is invoked outside the context of an xConnect or
6801: ** xCreate virtual table method then the behavior is undefined.
6802: **
6803: ** At present, there is only one option that may be configured using
6804: ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
6805: ** may be added in the future.
6806: */
6807: SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
6808:
6809: /*
6810: ** CAPI3REF: Virtual Table Configuration Options
6811: **
6812: ** These macros define the various options to the
6813: ** [sqlite3_vtab_config()] interface that [virtual table] implementations
6814: ** can use to customize and optimize their behavior.
6815: **
6816: ** <dl>
6817: ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
6818: ** <dd>Calls of the form
6819: ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
6820: ** where X is an integer. If X is zero, then the [virtual table] whose
6821: ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
6822: ** support constraints. In this configuration (which is the default) if
6823: ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
6824: ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
6825: ** specified as part of the users SQL statement, regardless of the actual
6826: ** ON CONFLICT mode specified.
6827: **
6828: ** If X is non-zero, then the virtual table implementation guarantees
6829: ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
6830: ** any modifications to internal or persistent data structures have been made.
6831: ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
6832: ** is able to roll back a statement or database transaction, and abandon
6833: ** or continue processing the current SQL statement as appropriate.
6834: ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
6835: ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
6836: ** had been ABORT.
6837: **
6838: ** Virtual table implementations that are required to handle OR REPLACE
6839: ** must do so within the [xUpdate] method. If a call to the
6840: ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
6841: ** CONFLICT policy is REPLACE, the virtual table implementation should
6842: ** silently replace the appropriate rows within the xUpdate callback and
6843: ** return SQLITE_OK. Or, if this is not possible, it may return
6844: ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
6845: ** constraint handling.
6846: ** </dl>
6847: */
6848: #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
6849:
6850: /*
6851: ** CAPI3REF: Determine The Virtual Table Conflict Policy
6852: **
6853: ** This function may only be called from within a call to the [xUpdate] method
6854: ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
6855: ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
6856: ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
6857: ** of the SQL statement that triggered the call to the [xUpdate] method of the
6858: ** [virtual table].
6859: */
6860: SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
6861:
6862: /*
6863: ** CAPI3REF: Conflict resolution modes
6864: **
6865: ** These constants are returned by [sqlite3_vtab_on_conflict()] to
6866: ** inform a [virtual table] implementation what the [ON CONFLICT] mode
6867: ** is for the SQL statement being evaluated.
6868: **
6869: ** Note that the [SQLITE_IGNORE] constant is also used as a potential
6870: ** return value from the [sqlite3_set_authorizer()] callback and that
6871: ** [SQLITE_ABORT] is also a [result code].
6872: */
6873: #define SQLITE_ROLLBACK 1
6874: /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
6875: #define SQLITE_FAIL 3
6876: /* #define SQLITE_ABORT 4 // Also an error code */
6877: #define SQLITE_REPLACE 5
6878:
6879:
6880:
6881: /*
6882: ** Undo the hack that converts floating point types to integer for
6883: ** builds on processors without floating point support.
6884: */
6885: #ifdef SQLITE_OMIT_FLOATING_POINT
6886: # undef double
6887: #endif
6888:
6889: #ifdef __cplusplus
6890: } /* End of the 'extern "C"' block */
6891: #endif
6892: #endif
6893:
6894: /*
6895: ** 2010 August 30
6896: **
6897: ** The author disclaims copyright to this source code. In place of
6898: ** a legal notice, here is a blessing:
6899: **
6900: ** May you do good and not evil.
6901: ** May you find forgiveness for yourself and forgive others.
6902: ** May you share freely, never taking more than you give.
6903: **
6904: *************************************************************************
6905: */
6906:
6907: #ifndef _SQLITE3RTREE_H_
6908: #define _SQLITE3RTREE_H_
6909:
6910:
6911: #ifdef __cplusplus
6912: extern "C" {
6913: #endif
6914:
6915: typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
6916:
6917: /*
6918: ** Register a geometry callback named zGeom that can be used as part of an
6919: ** R-Tree geometry query as follows:
6920: **
6921: ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
6922: */
6923: SQLITE_API int sqlite3_rtree_geometry_callback(
6924: sqlite3 *db,
6925: const char *zGeom,
6926: int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes),
6927: void *pContext
6928: );
6929:
6930:
6931: /*
6932: ** A pointer to a structure of the following type is passed as the first
6933: ** argument to callbacks registered using rtree_geometry_callback().
6934: */
6935: struct sqlite3_rtree_geometry {
6936: void *pContext; /* Copy of pContext passed to s_r_g_c() */
6937: int nParam; /* Size of array aParam[] */
6938: double *aParam; /* Parameters passed to SQL geom function */
6939: void *pUser; /* Callback implementation user data */
6940: void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
6941: };
6942:
6943:
6944: #ifdef __cplusplus
6945: } /* end of the 'extern "C"' block */
6946: #endif
6947:
6948: #endif /* ifndef _SQLITE3RTREE_H_ */
6949:
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