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