4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
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.
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.
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.
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.
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.
35 #include <stdarg.h> /* Needed for the definition of va_list */
38 ** Make sure we can call this stuff from C++.
46 ** Add the ability to override 'extern'
49 # define SQLITE_EXTERN extern
58 ** These no-op macros are used in front of interfaces to mark those
59 ** interfaces as either deprecated or experimental. New applications
60 ** should not use deprecated interfaces - they are support for backwards
61 ** compatibility only. Application writers should be aware that
62 ** experimental interfaces are subject to change in point releases.
64 ** These macros used to resolve to various kinds of compiler magic that
65 ** would generate warning messages when they were used. But that
66 ** compiler magic ended up generating such a flurry of bug reports
67 ** that we have taken it all out and gone back to using simple
70 #define SQLITE_DEPRECATED
71 #define SQLITE_EXPERIMENTAL
74 ** Ensure these symbols were not defined by some previous header file.
77 # undef SQLITE_VERSION
79 #ifdef SQLITE_VERSION_NUMBER
80 # undef SQLITE_VERSION_NUMBER
84 ** CAPI3REF: Compile-Time Library Version Numbers
86 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
87 ** evaluates to a string literal that is the SQLite version in the
88 ** format "X.Y.Z" where X is the major version number (always 3 for
89 ** SQLite3) and Y is the minor version number and Z is the release number.)^
90 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
91 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
92 ** numbers used in [SQLITE_VERSION].)^
93 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
94 ** be larger than the release from which it is derived. Either Y will
95 ** be held constant and Z will be incremented or else Y will be incremented
96 ** and Z will be reset to zero.
98 ** Since version 3.6.18, SQLite source code has been stored in the
99 ** <a href="http://www.fossil-scm.org/">Fossil configuration management
100 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
101 ** a string which identifies a particular check-in of SQLite
102 ** within its configuration management system. ^The SQLITE_SOURCE_ID
103 ** string contains the date and time of the check-in (UTC) and an SHA1
104 ** hash of the entire source tree.
106 ** See also: [sqlite3_libversion()],
107 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
108 ** [sqlite_version()] and [sqlite_source_id()].
110 #define SQLITE_VERSION "3.7.9"
111 #define SQLITE_VERSION_NUMBER 3007009
112 #define SQLITE_SOURCE_ID "2011-10-29 19:25:08 5b82ec6fbbd2f4195ad06dd911de3817373ad5bf"
115 ** CAPI3REF: Run-Time Library Version Numbers
116 ** KEYWORDS: sqlite3_version, sqlite3_sourceid
118 ** These interfaces provide the same information as the [SQLITE_VERSION],
119 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
120 ** but are associated with the library instead of the header file. ^(Cautious
121 ** programmers might include assert() statements in their application to
122 ** verify that values returned by these interfaces match the macros in
123 ** the header, and thus insure that the application is
124 ** compiled with matching library and header files.
127 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
128 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
129 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
130 ** </pre></blockquote>)^
132 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
133 ** macro. ^The sqlite3_libversion() function returns a pointer to the
134 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
135 ** function is provided for use in DLLs since DLL users usually do not have
136 ** direct access to string constants within the DLL. ^The
137 ** sqlite3_libversion_number() function returns an integer equal to
138 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
139 ** a pointer to a string constant whose value is the same as the
140 ** [SQLITE_SOURCE_ID] C preprocessor macro.
142 ** See also: [sqlite_version()] and [sqlite_source_id()].
144 SQLITE_API SQLITE_EXTERN
const char sqlite3_version
[];
145 SQLITE_API
const char *sqlite3_libversion(void);
146 SQLITE_API
const char *sqlite3_sourceid(void);
147 SQLITE_API
int sqlite3_libversion_number(void);
150 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
152 ** ^The sqlite3_compileoption_used() function returns 0 or 1
153 ** indicating whether the specified option was defined at
154 ** compile time. ^The SQLITE_ prefix may be omitted from the
155 ** option name passed to sqlite3_compileoption_used().
157 ** ^The sqlite3_compileoption_get() function allows iterating
158 ** over the list of options that were defined at compile time by
159 ** returning the N-th compile time option string. ^If N is out of range,
160 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
161 ** prefix is omitted from any strings returned by
162 ** sqlite3_compileoption_get().
164 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
165 ** and sqlite3_compileoption_get() may be omitted by specifying the
166 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
168 ** See also: SQL functions [sqlite_compileoption_used()] and
169 ** [sqlite_compileoption_get()] and the [compile_options pragma].
171 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
172 SQLITE_API
int sqlite3_compileoption_used(const char *zOptName
);
173 SQLITE_API
const char *sqlite3_compileoption_get(int N
);
177 ** CAPI3REF: Test To See If The Library Is Threadsafe
179 ** ^The sqlite3_threadsafe() function returns zero if and only if
180 ** SQLite was compiled mutexing code omitted due to the
181 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
183 ** SQLite can be compiled with or without mutexes. When
184 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
185 ** are enabled and SQLite is threadsafe. When the
186 ** [SQLITE_THREADSAFE] macro is 0,
187 ** the mutexes are omitted. Without the mutexes, it is not safe
188 ** to use SQLite concurrently from more than one thread.
190 ** Enabling mutexes incurs a measurable performance penalty.
191 ** So if speed is of utmost importance, it makes sense to disable
192 ** the mutexes. But for maximum safety, mutexes should be enabled.
193 ** ^The default behavior is for mutexes to be enabled.
195 ** This interface can be used by an application to make sure that the
196 ** version of SQLite that it is linking against was compiled with
197 ** the desired setting of the [SQLITE_THREADSAFE] macro.
199 ** This interface only reports on the compile-time mutex setting
200 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
201 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
202 ** can be fully or partially disabled using a call to [sqlite3_config()]
203 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
204 ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the
205 ** sqlite3_threadsafe() function shows only the compile-time setting of
206 ** thread safety, not any run-time changes to that setting made by
207 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
208 ** is unchanged by calls to sqlite3_config().)^
210 ** See the [threading mode] documentation for additional information.
212 SQLITE_API
int sqlite3_threadsafe(void);
215 ** CAPI3REF: Database Connection Handle
216 ** KEYWORDS: {database connection} {database connections}
218 ** Each open SQLite database is represented by a pointer to an instance of
219 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
220 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
221 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
222 ** is its destructor. There are many other interfaces (such as
223 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
224 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
227 typedef struct sqlite3 sqlite3
;
230 ** CAPI3REF: 64-Bit Integer Types
231 ** KEYWORDS: sqlite_int64 sqlite_uint64
233 ** Because there is no cross-platform way to specify 64-bit integer types
234 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
236 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
237 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
238 ** compatibility only.
240 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
241 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
242 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
243 ** between 0 and +18446744073709551615 inclusive.
245 #ifdef SQLITE_INT64_TYPE
246 typedef SQLITE_INT64_TYPE sqlite_int64
;
247 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64
;
248 #elif defined(_MSC_VER) || defined(__BORLANDC__)
249 typedef __int64 sqlite_int64
;
250 typedef unsigned __int64 sqlite_uint64
;
252 typedef long long int sqlite_int64
;
253 typedef unsigned long long int sqlite_uint64
;
255 typedef sqlite_int64 sqlite3_int64
;
256 typedef sqlite_uint64 sqlite3_uint64
;
259 ** If compiling for a processor that lacks floating point support,
260 ** substitute integer for floating-point.
262 #ifdef SQLITE_OMIT_FLOATING_POINT
263 # define double sqlite3_int64
267 ** CAPI3REF: Closing A Database Connection
269 ** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.
270 ** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is
271 ** successfully destroyed and all associated resources are deallocated.
273 ** Applications must [sqlite3_finalize | finalize] all [prepared statements]
274 ** and [sqlite3_blob_close | close] all [BLOB handles] associated with
275 ** the [sqlite3] object prior to attempting to close the object. ^If
276 ** sqlite3_close() is called on a [database connection] that still has
277 ** outstanding [prepared statements] or [BLOB handles], then it returns
280 ** ^If [sqlite3_close()] is invoked while a transaction is open,
281 ** the transaction is automatically rolled back.
283 ** The C parameter to [sqlite3_close(C)] must be either a NULL
284 ** pointer or an [sqlite3] object pointer obtained
285 ** from [sqlite3_open()], [sqlite3_open16()], or
286 ** [sqlite3_open_v2()], and not previously closed.
287 ** ^Calling sqlite3_close() with a NULL pointer argument is a
290 SQLITE_API
int sqlite3_close(sqlite3
*);
293 ** The type for a callback function.
294 ** This is legacy and deprecated. It is included for historical
295 ** compatibility and is not documented.
297 typedef int (*sqlite3_callback
)(void*,int,char**, char**);
300 ** CAPI3REF: One-Step Query Execution Interface
302 ** The sqlite3_exec() interface is a convenience wrapper around
303 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
304 ** that allows an application to run multiple statements of SQL
305 ** without having to use a lot of C code.
307 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
308 ** semicolon-separate SQL statements passed into its 2nd argument,
309 ** in the context of the [database connection] passed in as its 1st
310 ** argument. ^If the callback function of the 3rd argument to
311 ** sqlite3_exec() is not NULL, then it is invoked for each result row
312 ** coming out of the evaluated SQL statements. ^The 4th argument to
313 ** sqlite3_exec() is relayed through to the 1st argument of each
314 ** callback invocation. ^If the callback pointer to sqlite3_exec()
315 ** is NULL, then no callback is ever invoked and result rows are
318 ** ^If an error occurs while evaluating the SQL statements passed into
319 ** sqlite3_exec(), then execution of the current statement stops and
320 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
321 ** is not NULL then any error message is written into memory obtained
322 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
323 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
324 ** on error message strings returned through the 5th parameter of
325 ** of sqlite3_exec() after the error message string is no longer needed.
326 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
327 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
328 ** NULL before returning.
330 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
331 ** routine returns SQLITE_ABORT without invoking the callback again and
332 ** without running any subsequent SQL statements.
334 ** ^The 2nd argument to the sqlite3_exec() callback function is the
335 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
336 ** callback is an array of pointers to strings obtained as if from
337 ** [sqlite3_column_text()], one for each column. ^If an element of a
338 ** result row is NULL then the corresponding string pointer for the
339 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
340 ** sqlite3_exec() callback is an array of pointers to strings where each
341 ** entry represents the name of corresponding result column as obtained
342 ** from [sqlite3_column_name()].
344 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
345 ** to an empty string, or a pointer that contains only whitespace and/or
346 ** SQL comments, then no SQL statements are evaluated and the database
352 ** <li> The application must insure that the 1st parameter to sqlite3_exec()
353 ** is a valid and open [database connection].
354 ** <li> The application must not close [database connection] specified by
355 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
356 ** <li> The application must not modify the SQL statement text passed into
357 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
360 SQLITE_API
int sqlite3_exec(
361 sqlite3
*, /* An open database */
362 const char *sql
, /* SQL to be evaluated */
363 int (*callback
)(void*,int,char**,char**), /* Callback function */
364 void *, /* 1st argument to callback */
365 char **errmsg
/* Error msg written here */
369 ** CAPI3REF: Result Codes
370 ** KEYWORDS: SQLITE_OK {error code} {error codes}
371 ** KEYWORDS: {result code} {result codes}
373 ** Many SQLite functions return an integer result code from the set shown
374 ** here in order to indicates success or failure.
376 ** New error codes may be added in future versions of SQLite.
378 ** See also: [SQLITE_IOERR_READ | extended result codes],
379 ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
381 #define SQLITE_OK 0 /* Successful result */
382 /* beginning-of-error-codes */
383 #define SQLITE_ERROR 1 /* SQL error or missing database */
384 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
385 #define SQLITE_PERM 3 /* Access permission denied */
386 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
387 #define SQLITE_BUSY 5 /* The database file is locked */
388 #define SQLITE_LOCKED 6 /* A table in the database is locked */
389 #define SQLITE_NOMEM 7 /* A malloc() failed */
390 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
391 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
392 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
393 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
394 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
395 #define SQLITE_FULL 13 /* Insertion failed because database is full */
396 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
397 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
398 #define SQLITE_EMPTY 16 /* Database is empty */
399 #define SQLITE_SCHEMA 17 /* The database schema changed */
400 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
401 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
402 #define SQLITE_MISMATCH 20 /* Data type mismatch */
403 #define SQLITE_MISUSE 21 /* Library used incorrectly */
404 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
405 #define SQLITE_AUTH 23 /* Authorization denied */
406 #define SQLITE_FORMAT 24 /* Auxiliary database format error */
407 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
408 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
409 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
410 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
411 /* end-of-error-codes */
414 ** CAPI3REF: Extended Result Codes
415 ** KEYWORDS: {extended error code} {extended error codes}
416 ** KEYWORDS: {extended result code} {extended result codes}
418 ** In its default configuration, SQLite API routines return one of 26 integer
419 ** [SQLITE_OK | result codes]. However, experience has shown that many of
420 ** these result codes are too coarse-grained. They do not provide as
421 ** much information about problems as programmers might like. In an effort to
422 ** address this, newer versions of SQLite (version 3.3.8 and later) include
423 ** support for additional result codes that provide more detailed information
424 ** about errors. The extended result codes are enabled or disabled
425 ** on a per database connection basis using the
426 ** [sqlite3_extended_result_codes()] API.
428 ** Some of the available extended result codes are listed here.
429 ** One may expect the number of extended result codes will be expand
430 ** over time. Software that uses extended result codes should expect
431 ** to see new result codes in future releases of SQLite.
433 ** The SQLITE_OK result code will never be extended. It will always
436 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
437 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
438 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
439 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
440 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
441 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
442 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
443 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
444 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
445 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
446 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
447 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
448 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
449 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
450 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
451 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
452 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
453 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
454 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
455 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
456 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
457 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
458 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
459 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
460 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
461 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
462 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
463 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
466 ** CAPI3REF: Flags For File Open Operations
468 ** These bit values are intended for use in the
469 ** 3rd parameter to the [sqlite3_open_v2()] interface and
470 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
472 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
473 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
474 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
475 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
476 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
477 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
478 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
479 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
480 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
481 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
482 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
483 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
484 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
485 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
486 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
487 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
488 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
489 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
490 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
492 /* Reserved: 0x00F00000 */
495 ** CAPI3REF: Device Characteristics
497 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
498 ** object returns an integer which is a vector of the these
499 ** bit values expressing I/O characteristics of the mass storage
500 ** device that holds the file that the [sqlite3_io_methods]
503 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
504 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
505 ** mean that writes of blocks that are nnn bytes in size and
506 ** are aligned to an address which is an integer multiple of
507 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
508 ** that when data is appended to a file, the data is appended
509 ** first then the size of the file is extended, never the other
510 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
511 ** information is written to disk in the same order as calls
514 #define SQLITE_IOCAP_ATOMIC 0x00000001
515 #define SQLITE_IOCAP_ATOMIC512 0x00000002
516 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
517 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
518 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
519 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
520 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
521 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
522 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
523 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
524 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
525 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
528 ** CAPI3REF: File Locking Levels
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.
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
541 ** CAPI3REF: Synchronization Type Flags
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.
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().
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.)
566 #define SQLITE_SYNC_NORMAL 0x00002
567 #define SQLITE_SYNC_FULL 0x00003
568 #define SQLITE_SYNC_DATAONLY 0x00010
571 ** CAPI3REF: OS Interface Open File Handle
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.
581 typedef struct sqlite3_file sqlite3_file
;
582 struct sqlite3_file
{
583 const struct sqlite3_io_methods
*pMethods
; /* Methods for an open file */
587 ** CAPI3REF: OS Interface File Virtual Methods Object
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.
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
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.
608 ** The integer values to xLock() and xUnlock() are one of
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].
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.
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
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:
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]
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
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.
676 typedef struct sqlite3_io_methods sqlite3_io_methods
;
677 struct sqlite3_io_methods
{
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 */
701 ** CAPI3REF: Standard File Control Opcodes
703 ** These integer constants are opcodes for the xFileControl method
704 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
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
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
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.
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.
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.
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 work to provide robustness against
748 ** anti-virus programs. By default, the windows VFS will retry file read,
749 ** file write, and file delete opertions 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 those to 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.
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.
775 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
776 ** a write transaction to indicate that, unless it is rolled back for some
777 ** reason, the entire database file will be overwritten by the current
778 ** transaction. This is used by VACUUM operations.
780 #define SQLITE_FCNTL_LOCKSTATE 1
781 #define SQLITE_GET_LOCKPROXYFILE 2
782 #define SQLITE_SET_LOCKPROXYFILE 3
783 #define SQLITE_LAST_ERRNO 4
784 #define SQLITE_FCNTL_SIZE_HINT 5
785 #define SQLITE_FCNTL_CHUNK_SIZE 6
786 #define SQLITE_FCNTL_FILE_POINTER 7
787 #define SQLITE_FCNTL_SYNC_OMITTED 8
788 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
789 #define SQLITE_FCNTL_PERSIST_WAL 10
790 #define SQLITE_FCNTL_OVERWRITE 11
793 ** CAPI3REF: Mutex Handle
795 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
796 ** abstract type for a mutex object. The SQLite core never looks
797 ** at the internal representation of an [sqlite3_mutex]. It only
798 ** deals with pointers to the [sqlite3_mutex] object.
800 ** Mutexes are created using [sqlite3_mutex_alloc()].
802 typedef struct sqlite3_mutex sqlite3_mutex
;
805 ** CAPI3REF: OS Interface Object
807 ** An instance of the sqlite3_vfs object defines the interface between
808 ** the SQLite core and the underlying operating system. The "vfs"
809 ** in the name of the object stands for "virtual file system". See
810 ** the [VFS | VFS documentation] for further information.
812 ** The value of the iVersion field is initially 1 but may be larger in
813 ** future versions of SQLite. Additional fields may be appended to this
814 ** object when the iVersion value is increased. Note that the structure
815 ** of the sqlite3_vfs object changes in the transaction between
816 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
819 ** The szOsFile field is the size of the subclassed [sqlite3_file]
820 ** structure used by this VFS. mxPathname is the maximum length of
821 ** a pathname in this VFS.
823 ** Registered sqlite3_vfs objects are kept on a linked list formed by
824 ** the pNext pointer. The [sqlite3_vfs_register()]
825 ** and [sqlite3_vfs_unregister()] interfaces manage this list
826 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
827 ** searches the list. Neither the application code nor the VFS
828 ** implementation should use the pNext pointer.
830 ** The pNext field is the only field in the sqlite3_vfs
831 ** structure that SQLite will ever modify. SQLite will only access
832 ** or modify this field while holding a particular static mutex.
833 ** The application should never modify anything within the sqlite3_vfs
834 ** object once the object has been registered.
836 ** The zName field holds the name of the VFS module. The name must
837 ** be unique across all VFS modules.
839 ** [[sqlite3_vfs.xOpen]]
840 ** ^SQLite guarantees that the zFilename parameter to xOpen
841 ** is either a NULL pointer or string obtained
842 ** from xFullPathname() with an optional suffix added.
843 ** ^If a suffix is added to the zFilename parameter, it will
844 ** consist of a single "-" character followed by no more than
845 ** 10 alphanumeric and/or "-" characters.
846 ** ^SQLite further guarantees that
847 ** the string will be valid and unchanged until xClose() is
848 ** called. Because of the previous sentence,
849 ** the [sqlite3_file] can safely store a pointer to the
850 ** filename if it needs to remember the filename for some reason.
851 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
852 ** must invent its own temporary name for the file. ^Whenever the
853 ** xFilename parameter is NULL it will also be the case that the
854 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
856 ** The flags argument to xOpen() includes all bits set in
857 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
858 ** or [sqlite3_open16()] is used, then flags includes at least
859 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
860 ** If xOpen() opens a file read-only then it sets *pOutFlags to
861 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
863 ** ^(SQLite will also add one of the following flags to the xOpen()
864 ** call, depending on the object being opened:
867 ** <li> [SQLITE_OPEN_MAIN_DB]
868 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
869 ** <li> [SQLITE_OPEN_TEMP_DB]
870 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
871 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
872 ** <li> [SQLITE_OPEN_SUBJOURNAL]
873 ** <li> [SQLITE_OPEN_MASTER_JOURNAL]
874 ** <li> [SQLITE_OPEN_WAL]
877 ** The file I/O implementation can use the object type flags to
878 ** change the way it deals with files. For example, an application
879 ** that does not care about crash recovery or rollback might make
880 ** the open of a journal file a no-op. Writes to this journal would
881 ** also be no-ops, and any attempt to read the journal would return
882 ** SQLITE_IOERR. Or the implementation might recognize that a database
883 ** file will be doing page-aligned sector reads and writes in a random
884 ** order and set up its I/O subsystem accordingly.
886 ** SQLite might also add one of the following flags to the xOpen method:
889 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
890 ** <li> [SQLITE_OPEN_EXCLUSIVE]
893 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
894 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
895 ** will be set for TEMP databases and their journals, transient
896 ** databases, and subjournals.
898 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
899 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
900 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
901 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
902 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
903 ** be created, and that it is an error if it already exists.
904 ** It is <i>not</i> used to indicate the file should be opened
905 ** for exclusive access.
907 ** ^At least szOsFile bytes of memory are allocated by SQLite
908 ** to hold the [sqlite3_file] structure passed as the third
909 ** argument to xOpen. The xOpen method does not have to
910 ** allocate the structure; it should just fill it in. Note that
911 ** the xOpen method must set the sqlite3_file.pMethods to either
912 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
913 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
914 ** element will be valid after xOpen returns regardless of the success
915 ** or failure of the xOpen call.
917 ** [[sqlite3_vfs.xAccess]]
918 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
919 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
920 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
921 ** to test whether a file is at least readable. The file can be a
924 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
925 ** output buffer xFullPathname. The exact size of the output buffer
926 ** is also passed as a parameter to both methods. If the output buffer
927 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
928 ** handled as a fatal error by SQLite, vfs implementations should endeavor
929 ** to prevent this by setting mxPathname to a sufficiently large value.
931 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
932 ** interfaces are not strictly a part of the filesystem, but they are
933 ** included in the VFS structure for completeness.
934 ** The xRandomness() function attempts to return nBytes bytes
935 ** of good-quality randomness into zOut. The return value is
936 ** the actual number of bytes of randomness obtained.
937 ** The xSleep() method causes the calling thread to sleep for at
938 ** least the number of microseconds given. ^The xCurrentTime()
939 ** method returns a Julian Day Number for the current date and time as
940 ** a floating point value.
941 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
942 ** Day Number multiplied by 86400000 (the number of milliseconds in
944 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
945 ** date and time if that method is available (if iVersion is 2 or
946 ** greater and the function pointer is not NULL) and will fall back
947 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
949 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
950 ** are not used by the SQLite core. These optional interfaces are provided
951 ** by some VFSes to facilitate testing of the VFS code. By overriding
952 ** system calls with functions under its control, a test program can
953 ** simulate faults and error conditions that would otherwise be difficult
954 ** or impossible to induce. The set of system calls that can be overridden
955 ** varies from one VFS to another, and from one version of the same VFS to the
956 ** next. Applications that use these interfaces must be prepared for any
957 ** or all of these interfaces to be NULL or for their behavior to change
958 ** from one release to the next. Applications must not attempt to access
959 ** any of these methods if the iVersion of the VFS is less than 3.
961 typedef struct sqlite3_vfs sqlite3_vfs
;
962 typedef void (*sqlite3_syscall_ptr
)(void);
964 int iVersion
; /* Structure version number (currently 3) */
965 int szOsFile
; /* Size of subclassed sqlite3_file */
966 int mxPathname
; /* Maximum file pathname length */
967 sqlite3_vfs
*pNext
; /* Next registered VFS */
968 const char *zName
; /* Name of this virtual file system */
969 void *pAppData
; /* Pointer to application-specific data */
970 int (*xOpen
)(sqlite3_vfs
*, const char *zName
, sqlite3_file
*,
971 int flags
, int *pOutFlags
);
972 int (*xDelete
)(sqlite3_vfs
*, const char *zName
, int syncDir
);
973 int (*xAccess
)(sqlite3_vfs
*, const char *zName
, int flags
, int *pResOut
);
974 int (*xFullPathname
)(sqlite3_vfs
*, const char *zName
, int nOut
, char *zOut
);
975 void *(*xDlOpen
)(sqlite3_vfs
*, const char *zFilename
);
976 void (*xDlError
)(sqlite3_vfs
*, int nByte
, char *zErrMsg
);
977 void (*(*xDlSym
)(sqlite3_vfs
*,void*, const char *zSymbol
))(void);
978 void (*xDlClose
)(sqlite3_vfs
*, void*);
979 int (*xRandomness
)(sqlite3_vfs
*, int nByte
, char *zOut
);
980 int (*xSleep
)(sqlite3_vfs
*, int microseconds
);
981 int (*xCurrentTime
)(sqlite3_vfs
*, double*);
982 int (*xGetLastError
)(sqlite3_vfs
*, int, char *);
984 ** The methods above are in version 1 of the sqlite_vfs object
985 ** definition. Those that follow are added in version 2 or later
987 int (*xCurrentTimeInt64
)(sqlite3_vfs
*, sqlite3_int64
*);
989 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
990 ** Those below are for version 3 and greater.
992 int (*xSetSystemCall
)(sqlite3_vfs
*, const char *zName
, sqlite3_syscall_ptr
);
993 sqlite3_syscall_ptr (*xGetSystemCall
)(sqlite3_vfs
*, const char *zName
);
994 const char *(*xNextSystemCall
)(sqlite3_vfs
*, const char *zName
);
996 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
997 ** New fields may be appended in figure versions. The iVersion
998 ** value will increment whenever this happens.
1003 ** CAPI3REF: Flags for the xAccess VFS method
1005 ** These integer constants can be used as the third parameter to
1006 ** the xAccess method of an [sqlite3_vfs] object. They determine
1007 ** what kind of permissions the xAccess method is looking for.
1008 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1009 ** simply checks whether the file exists.
1010 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1011 ** checks whether the named directory is both readable and writable
1012 ** (in other words, if files can be added, removed, and renamed within
1014 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1015 ** [temp_store_directory pragma], though this could change in a future
1016 ** release of SQLite.
1017 ** With SQLITE_ACCESS_READ, the xAccess method
1018 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1019 ** currently unused, though it might be used in a future release of
1022 #define SQLITE_ACCESS_EXISTS 0
1023 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1024 #define SQLITE_ACCESS_READ 2 /* Unused */
1027 ** CAPI3REF: Flags for the xShmLock VFS method
1029 ** These integer constants define the various locking operations
1030 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1031 ** following are the only legal combinations of flags to the
1035 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1036 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1037 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1038 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1041 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1042 ** was given no the corresponding lock.
1044 ** The xShmLock method can transition between unlocked and SHARED or
1045 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1048 #define SQLITE_SHM_UNLOCK 1
1049 #define SQLITE_SHM_LOCK 2
1050 #define SQLITE_SHM_SHARED 4
1051 #define SQLITE_SHM_EXCLUSIVE 8
1054 ** CAPI3REF: Maximum xShmLock index
1056 ** The xShmLock method on [sqlite3_io_methods] may use values
1057 ** between 0 and this upper bound as its "offset" argument.
1058 ** The SQLite core will never attempt to acquire or release a
1059 ** lock outside of this range
1061 #define SQLITE_SHM_NLOCK 8
1065 ** CAPI3REF: Initialize The SQLite Library
1067 ** ^The sqlite3_initialize() routine initializes the
1068 ** SQLite library. ^The sqlite3_shutdown() routine
1069 ** deallocates any resources that were allocated by sqlite3_initialize().
1070 ** These routines are designed to aid in process initialization and
1071 ** shutdown on embedded systems. Workstation applications using
1072 ** SQLite normally do not need to invoke either of these routines.
1074 ** A call to sqlite3_initialize() is an "effective" call if it is
1075 ** the first time sqlite3_initialize() is invoked during the lifetime of
1076 ** the process, or if it is the first time sqlite3_initialize() is invoked
1077 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1078 ** of sqlite3_initialize() does any initialization. All other calls
1079 ** are harmless no-ops.)^
1081 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1082 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1083 ** an effective call to sqlite3_shutdown() does any deinitialization.
1084 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1086 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1087 ** is not. The sqlite3_shutdown() interface must only be called from a
1088 ** single thread. All open [database connections] must be closed and all
1089 ** other SQLite resources must be deallocated prior to invoking
1090 ** sqlite3_shutdown().
1092 ** Among other things, ^sqlite3_initialize() will invoke
1093 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1094 ** will invoke sqlite3_os_end().
1096 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1097 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1098 ** the library (perhaps it is unable to allocate a needed resource such
1099 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1101 ** ^The sqlite3_initialize() routine is called internally by many other
1102 ** SQLite interfaces so that an application usually does not need to
1103 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1104 ** calls sqlite3_initialize() so the SQLite library will be automatically
1105 ** initialized when [sqlite3_open()] is called if it has not be initialized
1106 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1107 ** compile-time option, then the automatic calls to sqlite3_initialize()
1108 ** are omitted and the application must call sqlite3_initialize() directly
1109 ** prior to using any other SQLite interface. For maximum portability,
1110 ** it is recommended that applications always invoke sqlite3_initialize()
1111 ** directly prior to using any other SQLite interface. Future releases
1112 ** of SQLite may require this. In other words, the behavior exhibited
1113 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1114 ** default behavior in some future release of SQLite.
1116 ** The sqlite3_os_init() routine does operating-system specific
1117 ** initialization of the SQLite library. The sqlite3_os_end()
1118 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1119 ** performed by these routines include allocation or deallocation
1120 ** of static resources, initialization of global variables,
1121 ** setting up a default [sqlite3_vfs] module, or setting up
1122 ** a default configuration using [sqlite3_config()].
1124 ** The application should never invoke either sqlite3_os_init()
1125 ** or sqlite3_os_end() directly. The application should only invoke
1126 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1127 ** interface is called automatically by sqlite3_initialize() and
1128 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1129 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1130 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1131 ** When [custom builds | built for other platforms]
1132 ** (using the [SQLITE_OS_OTHER=1] compile-time
1133 ** option) the application must supply a suitable implementation for
1134 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1135 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1136 ** must return [SQLITE_OK] on success and some other [error code] upon
1139 SQLITE_API
int sqlite3_initialize(void);
1140 SQLITE_API
int sqlite3_shutdown(void);
1141 SQLITE_API
int sqlite3_os_init(void);
1142 SQLITE_API
int sqlite3_os_end(void);
1145 ** CAPI3REF: Configuring The SQLite Library
1147 ** The sqlite3_config() interface is used to make global configuration
1148 ** changes to SQLite in order to tune SQLite to the specific needs of
1149 ** the application. The default configuration is recommended for most
1150 ** applications and so this routine is usually not necessary. It is
1151 ** provided to support rare applications with unusual needs.
1153 ** The sqlite3_config() interface is not threadsafe. The application
1154 ** must insure that no other SQLite interfaces are invoked by other
1155 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config()
1156 ** may only be invoked prior to library initialization using
1157 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1158 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1159 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1160 ** Note, however, that ^sqlite3_config() can be called as part of the
1161 ** implementation of an application-defined [sqlite3_os_init()].
1163 ** The first argument to sqlite3_config() is an integer
1164 ** [configuration option] that determines
1165 ** what property of SQLite is to be configured. Subsequent arguments
1166 ** vary depending on the [configuration option]
1167 ** in the first argument.
1169 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1170 ** ^If the option is unknown or SQLite is unable to set the option
1171 ** then this routine returns a non-zero [error code].
1173 SQLITE_API
int sqlite3_config(int, ...);
1176 ** CAPI3REF: Configure database connections
1178 ** The sqlite3_db_config() interface is used to make configuration
1179 ** changes to a [database connection]. The interface is similar to
1180 ** [sqlite3_config()] except that the changes apply to a single
1181 ** [database connection] (specified in the first argument).
1183 ** The second argument to sqlite3_db_config(D,V,...) is the
1184 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1185 ** that indicates what aspect of the [database connection] is being configured.
1186 ** Subsequent arguments vary depending on the configuration verb.
1188 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1189 ** the call is considered successful.
1191 SQLITE_API
int sqlite3_db_config(sqlite3
*, int op
, ...);
1194 ** CAPI3REF: Memory Allocation Routines
1196 ** An instance of this object defines the interface between SQLite
1197 ** and low-level memory allocation routines.
1199 ** This object is used in only one place in the SQLite interface.
1200 ** A pointer to an instance of this object is the argument to
1201 ** [sqlite3_config()] when the configuration option is
1202 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1203 ** By creating an instance of this object
1204 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1205 ** during configuration, an application can specify an alternative
1206 ** memory allocation subsystem for SQLite to use for all of its
1207 ** dynamic memory needs.
1209 ** Note that SQLite comes with several [built-in memory allocators]
1210 ** that are perfectly adequate for the overwhelming majority of applications
1211 ** and that this object is only useful to a tiny minority of applications
1212 ** with specialized memory allocation requirements. This object is
1213 ** also used during testing of SQLite in order to specify an alternative
1214 ** memory allocator that simulates memory out-of-memory conditions in
1215 ** order to verify that SQLite recovers gracefully from such
1218 ** The xMalloc, xRealloc, and xFree methods must work like the
1219 ** malloc(), realloc() and free() functions from the standard C library.
1220 ** ^SQLite guarantees that the second argument to
1221 ** xRealloc is always a value returned by a prior call to xRoundup.
1223 ** xSize should return the allocated size of a memory allocation
1224 ** previously obtained from xMalloc or xRealloc. The allocated size
1225 ** is always at least as big as the requested size but may be larger.
1227 ** The xRoundup method returns what would be the allocated size of
1228 ** a memory allocation given a particular requested size. Most memory
1229 ** allocators round up memory allocations at least to the next multiple
1230 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1231 ** Every memory allocation request coming in through [sqlite3_malloc()]
1232 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1233 ** that causes the corresponding memory allocation to fail.
1235 ** The xInit method initializes the memory allocator. (For example,
1236 ** it might allocate any require mutexes or initialize internal data
1237 ** structures. The xShutdown method is invoked (indirectly) by
1238 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1239 ** by xInit. The pAppData pointer is used as the only parameter to
1240 ** xInit and xShutdown.
1242 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1243 ** the xInit method, so the xInit method need not be threadsafe. The
1244 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1245 ** not need to be threadsafe either. For all other methods, SQLite
1246 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1247 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1248 ** it is by default) and so the methods are automatically serialized.
1249 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1250 ** methods must be threadsafe or else make their own arrangements for
1253 ** SQLite will never invoke xInit() more than once without an intervening
1254 ** call to xShutdown().
1256 typedef struct sqlite3_mem_methods sqlite3_mem_methods
;
1257 struct sqlite3_mem_methods
{
1258 void *(*xMalloc
)(int); /* Memory allocation function */
1259 void (*xFree
)(void*); /* Free a prior allocation */
1260 void *(*xRealloc
)(void*,int); /* Resize an allocation */
1261 int (*xSize
)(void*); /* Return the size of an allocation */
1262 int (*xRoundup
)(int); /* Round up request size to allocation size */
1263 int (*xInit
)(void*); /* Initialize the memory allocator */
1264 void (*xShutdown
)(void*); /* Deinitialize the memory allocator */
1265 void *pAppData
; /* Argument to xInit() and xShutdown() */
1269 ** CAPI3REF: Configuration Options
1270 ** KEYWORDS: {configuration option}
1272 ** These constants are the available integer configuration options that
1273 ** can be passed as the first argument to the [sqlite3_config()] interface.
1275 ** New configuration options may be added in future releases of SQLite.
1276 ** Existing configuration options might be discontinued. Applications
1277 ** should check the return code from [sqlite3_config()] to make sure that
1278 ** the call worked. The [sqlite3_config()] interface will return a
1279 ** non-zero [error code] if a discontinued or unsupported configuration option
1283 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1284 ** <dd>There are no arguments to this option. ^This option sets the
1285 ** [threading mode] to Single-thread. In other words, it disables
1286 ** all mutexing and puts SQLite into a mode where it can only be used
1287 ** by a single thread. ^If SQLite is compiled with
1288 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1289 ** it is not possible to change the [threading mode] from its default
1290 ** value of Single-thread and so [sqlite3_config()] will return
1291 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1292 ** configuration option.</dd>
1294 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1295 ** <dd>There are no arguments to this option. ^This option sets the
1296 ** [threading mode] to Multi-thread. In other words, it disables
1297 ** mutexing on [database connection] and [prepared statement] objects.
1298 ** The application is responsible for serializing access to
1299 ** [database connections] and [prepared statements]. But other mutexes
1300 ** are enabled so that SQLite will be safe to use in a multi-threaded
1301 ** environment as long as no two threads attempt to use the same
1302 ** [database connection] at the same time. ^If SQLite is compiled with
1303 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1304 ** it is not possible to set the Multi-thread [threading mode] and
1305 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1306 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1308 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1309 ** <dd>There are no arguments to this option. ^This option sets the
1310 ** [threading mode] to Serialized. In other words, this option enables
1311 ** all mutexes including the recursive
1312 ** mutexes on [database connection] and [prepared statement] objects.
1313 ** In this mode (which is the default when SQLite is compiled with
1314 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1315 ** to [database connections] and [prepared statements] so that the
1316 ** application is free to use the same [database connection] or the
1317 ** same [prepared statement] in different threads at the same time.
1318 ** ^If SQLite is compiled with
1319 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1320 ** it is not possible to set the Serialized [threading mode] and
1321 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1322 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1324 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1325 ** <dd> ^(This option takes a single argument which is a pointer to an
1326 ** instance of the [sqlite3_mem_methods] structure. The argument specifies
1327 ** alternative low-level memory allocation routines to be used in place of
1328 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1329 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1330 ** before the [sqlite3_config()] call returns.</dd>
1332 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1333 ** <dd> ^(This option takes a single argument which is a pointer to an
1334 ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods]
1335 ** structure is filled with the currently defined memory allocation routines.)^
1336 ** This option can be used to overload the default memory allocation
1337 ** routines with a wrapper that simulations memory allocation failure or
1338 ** tracks memory usage, for example. </dd>
1340 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1341 ** <dd> ^This option takes single argument of type int, interpreted as a
1342 ** boolean, which enables or disables the collection of memory allocation
1343 ** statistics. ^(When memory allocation statistics are disabled, the
1344 ** following SQLite interfaces become non-operational:
1346 ** <li> [sqlite3_memory_used()]
1347 ** <li> [sqlite3_memory_highwater()]
1348 ** <li> [sqlite3_soft_heap_limit64()]
1349 ** <li> [sqlite3_status()]
1351 ** ^Memory allocation statistics are enabled by default unless SQLite is
1352 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1353 ** allocation statistics are disabled by default.
1356 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1357 ** <dd> ^This option specifies a static memory buffer that SQLite can use for
1358 ** scratch memory. There are three arguments: A pointer an 8-byte
1359 ** aligned memory buffer from which the scratch allocations will be
1360 ** drawn, the size of each scratch allocation (sz),
1361 ** and the maximum number of scratch allocations (N). The sz
1362 ** argument must be a multiple of 16.
1363 ** The first argument must be a pointer to an 8-byte aligned buffer
1364 ** of at least sz*N bytes of memory.
1365 ** ^SQLite will use no more than two scratch buffers per thread. So
1366 ** N should be set to twice the expected maximum number of threads.
1367 ** ^SQLite will never require a scratch buffer that is more than 6
1368 ** times the database page size. ^If SQLite needs needs additional
1369 ** scratch memory beyond what is provided by this configuration option, then
1370 ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
1372 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1373 ** <dd> ^This option specifies a static memory buffer that SQLite can use for
1374 ** the database page cache with the default page cache implementation.
1375 ** This configuration should not be used if an application-define page
1376 ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option.
1377 ** There are three arguments to this option: A pointer to 8-byte aligned
1378 ** memory, the size of each page buffer (sz), and the number of pages (N).
1379 ** The sz argument should be the size of the largest database page
1380 ** (a power of two between 512 and 32768) plus a little extra for each
1381 ** page header. ^The page header size is 20 to 40 bytes depending on
1382 ** the host architecture. ^It is harmless, apart from the wasted memory,
1383 ** to make sz a little too large. The first
1384 ** argument should point to an allocation of at least sz*N bytes of memory.
1385 ** ^SQLite will use the memory provided by the first argument to satisfy its
1386 ** memory needs for the first N pages that it adds to cache. ^If additional
1387 ** page cache memory is needed beyond what is provided by this option, then
1388 ** SQLite goes to [sqlite3_malloc()] for the additional storage space.
1389 ** The pointer in the first argument must
1390 ** be aligned to an 8-byte boundary or subsequent behavior of SQLite
1391 ** will be undefined.</dd>
1393 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1394 ** <dd> ^This option specifies a static memory buffer that SQLite will use
1395 ** for all of its dynamic memory allocation needs beyond those provided
1396 ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
1397 ** There are three arguments: An 8-byte aligned pointer to the memory,
1398 ** the number of bytes in the memory buffer, and the minimum allocation size.
1399 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1400 ** to using its default memory allocator (the system malloc() implementation),
1401 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1402 ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1403 ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
1404 ** allocator is engaged to handle all of SQLites memory allocation needs.
1405 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1406 ** boundary or subsequent behavior of SQLite will be undefined.
1407 ** The minimum allocation size is capped at 2**12. Reasonable values
1408 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1410 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1411 ** <dd> ^(This option takes a single argument which is a pointer to an
1412 ** instance of the [sqlite3_mutex_methods] structure. The argument specifies
1413 ** alternative low-level mutex routines to be used in place
1414 ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the
1415 ** content of the [sqlite3_mutex_methods] structure before the call to
1416 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1417 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1418 ** the entire mutexing subsystem is omitted from the build and hence calls to
1419 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1420 ** return [SQLITE_ERROR].</dd>
1422 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1423 ** <dd> ^(This option takes a single argument which is a pointer to an
1424 ** instance of the [sqlite3_mutex_methods] structure. The
1425 ** [sqlite3_mutex_methods]
1426 ** structure is filled with the currently defined mutex routines.)^
1427 ** This option can be used to overload the default mutex allocation
1428 ** routines with a wrapper used to track mutex usage for performance
1429 ** profiling or testing, for example. ^If SQLite is compiled with
1430 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1431 ** the entire mutexing subsystem is omitted from the build and hence calls to
1432 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1433 ** return [SQLITE_ERROR].</dd>
1435 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1436 ** <dd> ^(This option takes two arguments that determine the default
1437 ** memory allocation for the lookaside memory allocator on each
1438 ** [database connection]. The first argument is the
1439 ** size of each lookaside buffer slot and the second is the number of
1440 ** slots allocated to each database connection.)^ ^(This option sets the
1441 ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1442 ** verb to [sqlite3_db_config()] can be used to change the lookaside
1443 ** configuration on individual connections.)^ </dd>
1445 ** [[SQLITE_CONFIG_PCACHE]] <dt>SQLITE_CONFIG_PCACHE</dt>
1446 ** <dd> ^(This option takes a single argument which is a pointer to
1447 ** an [sqlite3_pcache_methods] object. This object specifies the interface
1448 ** to a custom page cache implementation.)^ ^SQLite makes a copy of the
1449 ** object and uses it for page cache memory allocations.</dd>
1451 ** [[SQLITE_CONFIG_GETPCACHE]] <dt>SQLITE_CONFIG_GETPCACHE</dt>
1452 ** <dd> ^(This option takes a single argument which is a pointer to an
1453 ** [sqlite3_pcache_methods] object. SQLite copies of the current
1454 ** page cache implementation into that object.)^ </dd>
1456 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1457 ** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1458 ** function with a call signature of void(*)(void*,int,const char*),
1459 ** and a pointer to void. ^If the function pointer is not NULL, it is
1460 ** invoked by [sqlite3_log()] to process each logging event. ^If the
1461 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1462 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1463 ** passed through as the first parameter to the application-defined logger
1464 ** function whenever that function is invoked. ^The second parameter to
1465 ** the logger function is a copy of the first parameter to the corresponding
1466 ** [sqlite3_log()] call and is intended to be a [result code] or an
1467 ** [extended result code]. ^The third parameter passed to the logger is
1468 ** log message after formatting via [sqlite3_snprintf()].
1469 ** The SQLite logging interface is not reentrant; the logger function
1470 ** supplied by the application must not invoke any SQLite interface.
1471 ** In a multi-threaded application, the application-defined logger
1472 ** function must be threadsafe. </dd>
1474 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1475 ** <dd> This option takes a single argument of type int. If non-zero, then
1476 ** URI handling is globally enabled. If the parameter is zero, then URI handling
1477 ** is globally disabled. If URI handling is globally enabled, all filenames
1478 ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
1479 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1480 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1481 ** connection is opened. If it is globally disabled, filenames are
1482 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1483 ** database connection is opened. By default, URI handling is globally
1484 ** disabled. The default value may be changed by compiling with the
1485 ** [SQLITE_USE_URI] symbol defined.
1488 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1489 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1490 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1491 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1492 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1493 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
1494 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1495 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1496 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1497 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1498 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1499 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1500 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1501 #define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */
1502 #define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */
1503 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1504 #define SQLITE_CONFIG_URI 17 /* int */
1507 ** CAPI3REF: Database Connection Configuration Options
1509 ** These constants are the available integer configuration options that
1510 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
1512 ** New configuration options may be added in future releases of SQLite.
1513 ** Existing configuration options might be discontinued. Applications
1514 ** should check the return code from [sqlite3_db_config()] to make sure that
1515 ** the call worked. ^The [sqlite3_db_config()] interface will return a
1516 ** non-zero [error code] if a discontinued or unsupported configuration option
1520 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1521 ** <dd> ^This option takes three additional arguments that determine the
1522 ** [lookaside memory allocator] configuration for the [database connection].
1523 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1524 ** pointer to a memory buffer to use for lookaside memory.
1525 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1526 ** may be NULL in which case SQLite will allocate the
1527 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1528 ** size of each lookaside buffer slot. ^The third argument is the number of
1529 ** slots. The size of the buffer in the first argument must be greater than
1530 ** or equal to the product of the second and third arguments. The buffer
1531 ** must be aligned to an 8-byte boundary. ^If the second argument to
1532 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1533 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
1534 ** configuration for a database connection can only be changed when that
1535 ** connection is not currently using lookaside memory, or in other words
1536 ** when the "current value" returned by
1537 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1538 ** Any attempt to change the lookaside memory configuration when lookaside
1539 ** memory is in use leaves the configuration unchanged and returns
1540 ** [SQLITE_BUSY].)^</dd>
1542 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
1543 ** <dd> ^This option is used to enable or disable the enforcement of
1544 ** [foreign key constraints]. There should be two additional arguments.
1545 ** The first argument is an integer which is 0 to disable FK enforcement,
1546 ** positive to enable FK enforcement or negative to leave FK enforcement
1547 ** unchanged. The second parameter is a pointer to an integer into which
1548 ** is written 0 or 1 to indicate whether FK enforcement is off or on
1549 ** following this call. The second parameter may be a NULL pointer, in
1550 ** which case the FK enforcement setting is not reported back. </dd>
1552 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
1553 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
1554 ** There should be two additional arguments.
1555 ** The first argument is an integer which is 0 to disable triggers,
1556 ** positive to enable triggers or negative to leave the setting unchanged.
1557 ** The second parameter is a pointer to an integer into which
1558 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
1559 ** following this call. The second parameter may be a NULL pointer, in
1560 ** which case the trigger setting is not reported back. </dd>
1564 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
1565 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
1566 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
1570 ** CAPI3REF: Enable Or Disable Extended Result Codes
1572 ** ^The sqlite3_extended_result_codes() routine enables or disables the
1573 ** [extended result codes] feature of SQLite. ^The extended result
1574 ** codes are disabled by default for historical compatibility.
1576 SQLITE_API
int sqlite3_extended_result_codes(sqlite3
*, int onoff
);
1579 ** CAPI3REF: Last Insert Rowid
1581 ** ^Each entry in an SQLite table has a unique 64-bit signed
1582 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
1583 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
1584 ** names are not also used by explicitly declared columns. ^If
1585 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
1586 ** is another alias for the rowid.
1588 ** ^This routine returns the [rowid] of the most recent
1589 ** successful [INSERT] into the database from the [database connection]
1590 ** in the first argument. ^As of SQLite version 3.7.7, this routines
1591 ** records the last insert rowid of both ordinary tables and [virtual tables].
1592 ** ^If no successful [INSERT]s
1593 ** have ever occurred on that database connection, zero is returned.
1595 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
1596 ** method, then this routine will return the [rowid] of the inserted
1597 ** row as long as the trigger or virtual table method is running.
1598 ** But once the trigger or virtual table method ends, the value returned
1599 ** by this routine reverts to what it was before the trigger or virtual
1600 ** table method began.)^
1602 ** ^An [INSERT] that fails due to a constraint violation is not a
1603 ** successful [INSERT] and does not change the value returned by this
1604 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
1605 ** and INSERT OR ABORT make no changes to the return value of this
1606 ** routine when their insertion fails. ^(When INSERT OR REPLACE
1607 ** encounters a constraint violation, it does not fail. The
1608 ** INSERT continues to completion after deleting rows that caused
1609 ** the constraint problem so INSERT OR REPLACE will always change
1610 ** the return value of this interface.)^
1612 ** ^For the purposes of this routine, an [INSERT] is considered to
1613 ** be successful even if it is subsequently rolled back.
1615 ** This function is accessible to SQL statements via the
1616 ** [last_insert_rowid() SQL function].
1618 ** If a separate thread performs a new [INSERT] on the same
1619 ** database connection while the [sqlite3_last_insert_rowid()]
1620 ** function is running and thus changes the last insert [rowid],
1621 ** then the value returned by [sqlite3_last_insert_rowid()] is
1622 ** unpredictable and might not equal either the old or the new
1623 ** last insert [rowid].
1625 SQLITE_API sqlite3_int64
sqlite3_last_insert_rowid(sqlite3
*);
1628 ** CAPI3REF: Count The Number Of Rows Modified
1630 ** ^This function returns the number of database rows that were changed
1631 ** or inserted or deleted by the most recently completed SQL statement
1632 ** on the [database connection] specified by the first parameter.
1633 ** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
1634 ** or [DELETE] statement are counted. Auxiliary changes caused by
1635 ** triggers or [foreign key actions] are not counted.)^ Use the
1636 ** [sqlite3_total_changes()] function to find the total number of changes
1637 ** including changes caused by triggers and foreign key actions.
1639 ** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
1640 ** are not counted. Only real table changes are counted.
1642 ** ^(A "row change" is a change to a single row of a single table
1643 ** caused by an INSERT, DELETE, or UPDATE statement. Rows that
1644 ** are changed as side effects of [REPLACE] constraint resolution,
1645 ** rollback, ABORT processing, [DROP TABLE], or by any other
1646 ** mechanisms do not count as direct row changes.)^
1648 ** A "trigger context" is a scope of execution that begins and
1649 ** ends with the script of a [CREATE TRIGGER | trigger].
1650 ** Most SQL statements are
1651 ** evaluated outside of any trigger. This is the "top level"
1652 ** trigger context. If a trigger fires from the top level, a
1653 ** new trigger context is entered for the duration of that one
1654 ** trigger. Subtriggers create subcontexts for their duration.
1656 ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
1657 ** not create a new trigger context.
1659 ** ^This function returns the number of direct row changes in the
1660 ** most recent INSERT, UPDATE, or DELETE statement within the same
1663 ** ^Thus, when called from the top level, this function returns the
1664 ** number of changes in the most recent INSERT, UPDATE, or DELETE
1665 ** that also occurred at the top level. ^(Within the body of a trigger,
1666 ** the sqlite3_changes() interface can be called to find the number of
1667 ** changes in the most recently completed INSERT, UPDATE, or DELETE
1668 ** statement within the body of the same trigger.
1669 ** However, the number returned does not include changes
1670 ** caused by subtriggers since those have their own context.)^
1672 ** See also the [sqlite3_total_changes()] interface, the
1673 ** [count_changes pragma], and the [changes() SQL function].
1675 ** If a separate thread makes changes on the same database connection
1676 ** while [sqlite3_changes()] is running then the value returned
1677 ** is unpredictable and not meaningful.
1679 SQLITE_API
int sqlite3_changes(sqlite3
*);
1682 ** CAPI3REF: Total Number Of Rows Modified
1684 ** ^This function returns the number of row changes caused by [INSERT],
1685 ** [UPDATE] or [DELETE] statements since the [database connection] was opened.
1686 ** ^(The count returned by sqlite3_total_changes() includes all changes
1687 ** from all [CREATE TRIGGER | trigger] contexts and changes made by
1688 ** [foreign key actions]. However,
1689 ** the count does not include changes used to implement [REPLACE] constraints,
1690 ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The
1691 ** count does not include rows of views that fire an [INSTEAD OF trigger],
1692 ** though if the INSTEAD OF trigger makes changes of its own, those changes
1694 ** ^The sqlite3_total_changes() function counts the changes as soon as
1695 ** the statement that makes them is completed (when the statement handle
1696 ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
1698 ** See also the [sqlite3_changes()] interface, the
1699 ** [count_changes pragma], and the [total_changes() SQL function].
1701 ** If a separate thread makes changes on the same database connection
1702 ** while [sqlite3_total_changes()] is running then the value
1703 ** returned is unpredictable and not meaningful.
1705 SQLITE_API
int sqlite3_total_changes(sqlite3
*);
1708 ** CAPI3REF: Interrupt A Long-Running Query
1710 ** ^This function causes any pending database operation to abort and
1711 ** return at its earliest opportunity. This routine is typically
1712 ** called in response to a user action such as pressing "Cancel"
1713 ** or Ctrl-C where the user wants a long query operation to halt
1716 ** ^It is safe to call this routine from a thread different from the
1717 ** thread that is currently running the database operation. But it
1718 ** is not safe to call this routine with a [database connection] that
1719 ** is closed or might close before sqlite3_interrupt() returns.
1721 ** ^If an SQL operation is very nearly finished at the time when
1722 ** sqlite3_interrupt() is called, then it might not have an opportunity
1723 ** to be interrupted and might continue to completion.
1725 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
1726 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
1727 ** that is inside an explicit transaction, then the entire transaction
1728 ** will be rolled back automatically.
1730 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
1731 ** SQL statements on [database connection] D complete. ^Any new SQL statements
1732 ** that are started after the sqlite3_interrupt() call and before the
1733 ** running statements reaches zero are interrupted as if they had been
1734 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
1735 ** that are started after the running statement count reaches zero are
1736 ** not effected by the sqlite3_interrupt().
1737 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
1738 ** SQL statements is a no-op and has no effect on SQL statements
1739 ** that are started after the sqlite3_interrupt() call returns.
1741 ** If the database connection closes while [sqlite3_interrupt()]
1742 ** is running then bad things will likely happen.
1744 SQLITE_API
void sqlite3_interrupt(sqlite3
*);
1747 ** CAPI3REF: Determine If An SQL Statement Is Complete
1749 ** These routines are useful during command-line input to determine if the
1750 ** currently entered text seems to form a complete SQL statement or
1751 ** if additional input is needed before sending the text into
1752 ** SQLite for parsing. ^These routines return 1 if the input string
1753 ** appears to be a complete SQL statement. ^A statement is judged to be
1754 ** complete if it ends with a semicolon token and is not a prefix of a
1755 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
1756 ** string literals or quoted identifier names or comments are not
1757 ** independent tokens (they are part of the token in which they are
1758 ** embedded) and thus do not count as a statement terminator. ^Whitespace
1759 ** and comments that follow the final semicolon are ignored.
1761 ** ^These routines return 0 if the statement is incomplete. ^If a
1762 ** memory allocation fails, then SQLITE_NOMEM is returned.
1764 ** ^These routines do not parse the SQL statements thus
1765 ** will not detect syntactically incorrect SQL.
1767 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
1768 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
1769 ** automatically by sqlite3_complete16(). If that initialization fails,
1770 ** then the return value from sqlite3_complete16() will be non-zero
1771 ** regardless of whether or not the input SQL is complete.)^
1773 ** The input to [sqlite3_complete()] must be a zero-terminated
1776 ** The input to [sqlite3_complete16()] must be a zero-terminated
1777 ** UTF-16 string in native byte order.
1779 SQLITE_API
int sqlite3_complete(const char *sql
);
1780 SQLITE_API
int sqlite3_complete16(const void *sql
);
1783 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
1785 ** ^This routine sets a callback function that might be invoked whenever
1786 ** an attempt is made to open a database table that another thread
1787 ** or process has locked.
1789 ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
1790 ** is returned immediately upon encountering the lock. ^If the busy callback
1791 ** is not NULL, then the callback might be invoked with two arguments.
1793 ** ^The first argument to the busy handler is a copy of the void* pointer which
1794 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
1795 ** the busy handler callback is the number of times that the busy handler has
1796 ** been invoked for this locking event. ^If the
1797 ** busy callback returns 0, then no additional attempts are made to
1798 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
1799 ** ^If the callback returns non-zero, then another attempt
1800 ** is made to open the database for reading and the cycle repeats.
1802 ** The presence of a busy handler does not guarantee that it will be invoked
1803 ** when there is lock contention. ^If SQLite determines that invoking the busy
1804 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
1805 ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
1806 ** Consider a scenario where one process is holding a read lock that
1807 ** it is trying to promote to a reserved lock and
1808 ** a second process is holding a reserved lock that it is trying
1809 ** to promote to an exclusive lock. The first process cannot proceed
1810 ** because it is blocked by the second and the second process cannot
1811 ** proceed because it is blocked by the first. If both processes
1812 ** invoke the busy handlers, neither will make any progress. Therefore,
1813 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
1814 ** will induce the first process to release its read lock and allow
1815 ** the second process to proceed.
1817 ** ^The default busy callback is NULL.
1819 ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
1820 ** when SQLite is in the middle of a large transaction where all the
1821 ** changes will not fit into the in-memory cache. SQLite will
1822 ** already hold a RESERVED lock on the database file, but it needs
1823 ** to promote this lock to EXCLUSIVE so that it can spill cache
1824 ** pages into the database file without harm to concurrent
1825 ** readers. ^If it is unable to promote the lock, then the in-memory
1826 ** cache will be left in an inconsistent state and so the error
1827 ** code is promoted from the relatively benign [SQLITE_BUSY] to
1828 ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion
1829 ** forces an automatic rollback of the changes. See the
1830 ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
1831 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why
1832 ** this is important.
1834 ** ^(There can only be a single busy handler defined for each
1835 ** [database connection]. Setting a new busy handler clears any
1836 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
1837 ** will also set or clear the busy handler.
1839 ** The busy callback should not take any actions which modify the
1840 ** database connection that invoked the busy handler. Any such actions
1841 ** result in undefined behavior.
1843 ** A busy handler must not close the database connection
1844 ** or [prepared statement] that invoked the busy handler.
1846 SQLITE_API
int sqlite3_busy_handler(sqlite3
*, int(*)(void*,int), void*);
1849 ** CAPI3REF: Set A Busy Timeout
1851 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
1852 ** for a specified amount of time when a table is locked. ^The handler
1853 ** will sleep multiple times until at least "ms" milliseconds of sleeping
1854 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
1855 ** the handler returns 0 which causes [sqlite3_step()] to return
1856 ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
1858 ** ^Calling this routine with an argument less than or equal to zero
1859 ** turns off all busy handlers.
1861 ** ^(There can only be a single busy handler for a particular
1862 ** [database connection] any any given moment. If another busy handler
1863 ** was defined (using [sqlite3_busy_handler()]) prior to calling
1864 ** this routine, that other busy handler is cleared.)^
1866 SQLITE_API
int sqlite3_busy_timeout(sqlite3
*, int ms
);
1869 ** CAPI3REF: Convenience Routines For Running Queries
1871 ** This is a legacy interface that is preserved for backwards compatibility.
1872 ** Use of this interface is not recommended.
1874 ** Definition: A <b>result table</b> is memory data structure created by the
1875 ** [sqlite3_get_table()] interface. A result table records the
1876 ** complete query results from one or more queries.
1878 ** The table conceptually has a number of rows and columns. But
1879 ** these numbers are not part of the result table itself. These
1880 ** numbers are obtained separately. Let N be the number of rows
1881 ** and M be the number of columns.
1883 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
1884 ** There are (N+1)*M elements in the array. The first M pointers point
1885 ** to zero-terminated strings that contain the names of the columns.
1886 ** The remaining entries all point to query results. NULL values result
1887 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
1888 ** string representation as returned by [sqlite3_column_text()].
1890 ** A result table might consist of one or more memory allocations.
1891 ** It is not safe to pass a result table directly to [sqlite3_free()].
1892 ** A result table should be deallocated using [sqlite3_free_table()].
1894 ** ^(As an example of the result table format, suppose a query result
1897 ** <blockquote><pre>
1899 ** -----------------------
1903 ** </pre></blockquote>
1905 ** There are two column (M==2) and three rows (N==3). Thus the
1906 ** result table has 8 entries. Suppose the result table is stored
1907 ** in an array names azResult. Then azResult holds this content:
1909 ** <blockquote><pre>
1910 ** azResult[0] = "Name";
1911 ** azResult[1] = "Age";
1912 ** azResult[2] = "Alice";
1913 ** azResult[3] = "43";
1914 ** azResult[4] = "Bob";
1915 ** azResult[5] = "28";
1916 ** azResult[6] = "Cindy";
1917 ** azResult[7] = "21";
1918 ** </pre></blockquote>)^
1920 ** ^The sqlite3_get_table() function evaluates one or more
1921 ** semicolon-separated SQL statements in the zero-terminated UTF-8
1922 ** string of its 2nd parameter and returns a result table to the
1923 ** pointer given in its 3rd parameter.
1925 ** After the application has finished with the result from sqlite3_get_table(),
1926 ** it must pass the result table pointer to sqlite3_free_table() in order to
1927 ** release the memory that was malloced. Because of the way the
1928 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
1929 ** function must not try to call [sqlite3_free()] directly. Only
1930 ** [sqlite3_free_table()] is able to release the memory properly and safely.
1932 ** The sqlite3_get_table() interface is implemented as a wrapper around
1933 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
1934 ** to any internal data structures of SQLite. It uses only the public
1935 ** interface defined here. As a consequence, errors that occur in the
1936 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
1937 ** reflected in subsequent calls to [sqlite3_errcode()] or
1938 ** [sqlite3_errmsg()].
1940 SQLITE_API
int sqlite3_get_table(
1941 sqlite3
*db
, /* An open database */
1942 const char *zSql
, /* SQL to be evaluated */
1943 char ***pazResult
, /* Results of the query */
1944 int *pnRow
, /* Number of result rows written here */
1945 int *pnColumn
, /* Number of result columns written here */
1946 char **pzErrmsg
/* Error msg written here */
1948 SQLITE_API
void sqlite3_free_table(char **result
);
1951 ** CAPI3REF: Formatted String Printing Functions
1953 ** These routines are work-alikes of the "printf()" family of functions
1954 ** from the standard C library.
1956 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
1957 ** results into memory obtained from [sqlite3_malloc()].
1958 ** The strings returned by these two routines should be
1959 ** released by [sqlite3_free()]. ^Both routines return a
1960 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
1961 ** memory to hold the resulting string.
1963 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
1964 ** the standard C library. The result is written into the
1965 ** buffer supplied as the second parameter whose size is given by
1966 ** the first parameter. Note that the order of the
1967 ** first two parameters is reversed from snprintf().)^ This is an
1968 ** historical accident that cannot be fixed without breaking
1969 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
1970 ** returns a pointer to its buffer instead of the number of
1971 ** characters actually written into the buffer.)^ We admit that
1972 ** the number of characters written would be a more useful return
1973 ** value but we cannot change the implementation of sqlite3_snprintf()
1974 ** now without breaking compatibility.
1976 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
1977 ** guarantees that the buffer is always zero-terminated. ^The first
1978 ** parameter "n" is the total size of the buffer, including space for
1979 ** the zero terminator. So the longest string that can be completely
1980 ** written will be n-1 characters.
1982 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
1984 ** These routines all implement some additional formatting
1985 ** options that are useful for constructing SQL statements.
1986 ** All of the usual printf() formatting options apply. In addition, there
1987 ** is are "%q", "%Q", and "%z" options.
1989 ** ^(The %q option works like %s in that it substitutes a null-terminated
1990 ** string from the argument list. But %q also doubles every '\'' character.
1991 ** %q is designed for use inside a string literal.)^ By doubling each '\''
1992 ** character it escapes that character and allows it to be inserted into
1995 ** For example, assume the string variable zText contains text as follows:
1997 ** <blockquote><pre>
1998 ** char *zText = "It's a happy day!";
1999 ** </pre></blockquote>
2001 ** One can use this text in an SQL statement as follows:
2003 ** <blockquote><pre>
2004 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2005 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2006 ** sqlite3_free(zSQL);
2007 ** </pre></blockquote>
2009 ** Because the %q format string is used, the '\'' character in zText
2010 ** is escaped and the SQL generated is as follows:
2012 ** <blockquote><pre>
2013 ** INSERT INTO table1 VALUES('It''s a happy day!')
2014 ** </pre></blockquote>
2016 ** This is correct. Had we used %s instead of %q, the generated SQL
2017 ** would have looked like this:
2019 ** <blockquote><pre>
2020 ** INSERT INTO table1 VALUES('It's a happy day!');
2021 ** </pre></blockquote>
2023 ** This second example is an SQL syntax error. As a general rule you should
2024 ** always use %q instead of %s when inserting text into a string literal.
2026 ** ^(The %Q option works like %q except it also adds single quotes around
2027 ** the outside of the total string. Additionally, if the parameter in the
2028 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2029 ** single quotes).)^ So, for example, one could say:
2031 ** <blockquote><pre>
2032 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2033 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2034 ** sqlite3_free(zSQL);
2035 ** </pre></blockquote>
2037 ** The code above will render a correct SQL statement in the zSQL
2038 ** variable even if the zText variable is a NULL pointer.
2040 ** ^(The "%z" formatting option works like "%s" but with the
2041 ** addition that after the string has been read and copied into
2042 ** the result, [sqlite3_free()] is called on the input string.)^
2044 SQLITE_API
char *sqlite3_mprintf(const char*,...);
2045 SQLITE_API
char *sqlite3_vmprintf(const char*, va_list);
2046 SQLITE_API
char *sqlite3_snprintf(int,char*,const char*, ...);
2047 SQLITE_API
char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2050 ** CAPI3REF: Memory Allocation Subsystem
2052 ** The SQLite core uses these three routines for all of its own
2053 ** internal memory allocation needs. "Core" in the previous sentence
2054 ** does not include operating-system specific VFS implementation. The
2055 ** Windows VFS uses native malloc() and free() for some operations.
2057 ** ^The sqlite3_malloc() routine returns a pointer to a block
2058 ** of memory at least N bytes in length, where N is the parameter.
2059 ** ^If sqlite3_malloc() is unable to obtain sufficient free
2060 ** memory, it returns a NULL pointer. ^If the parameter N to
2061 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2064 ** ^Calling sqlite3_free() with a pointer previously returned
2065 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2066 ** that it might be reused. ^The sqlite3_free() routine is
2067 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
2068 ** to sqlite3_free() is harmless. After being freed, memory
2069 ** should neither be read nor written. Even reading previously freed
2070 ** memory might result in a segmentation fault or other severe error.
2071 ** Memory corruption, a segmentation fault, or other severe error
2072 ** might result if sqlite3_free() is called with a non-NULL pointer that
2073 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2075 ** ^(The sqlite3_realloc() interface attempts to resize a
2076 ** prior memory allocation to be at least N bytes, where N is the
2077 ** second parameter. The memory allocation to be resized is the first
2078 ** parameter.)^ ^ If the first parameter to sqlite3_realloc()
2079 ** is a NULL pointer then its behavior is identical to calling
2080 ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
2081 ** ^If the second parameter to sqlite3_realloc() is zero or
2082 ** negative then the behavior is exactly the same as calling
2083 ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
2084 ** ^sqlite3_realloc() returns a pointer to a memory allocation
2085 ** of at least N bytes in size or NULL if sufficient memory is unavailable.
2086 ** ^If M is the size of the prior allocation, then min(N,M) bytes
2087 ** of the prior allocation are copied into the beginning of buffer returned
2088 ** by sqlite3_realloc() and the prior allocation is freed.
2089 ** ^If sqlite3_realloc() returns NULL, then the prior allocation
2092 ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
2093 ** is always aligned to at least an 8 byte boundary, or to a
2094 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2097 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2098 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2099 ** implementation of these routines to be omitted. That capability
2100 ** is no longer provided. Only built-in memory allocators can be used.
2102 ** The Windows OS interface layer calls
2103 ** the system malloc() and free() directly when converting
2104 ** filenames between the UTF-8 encoding used by SQLite
2105 ** and whatever filename encoding is used by the particular Windows
2106 ** installation. Memory allocation errors are detected, but
2107 ** they are reported back as [SQLITE_CANTOPEN] or
2108 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2110 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2111 ** must be either NULL or else pointers obtained from a prior
2112 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2113 ** not yet been released.
2115 ** The application must not read or write any part of
2116 ** a block of memory after it has been released using
2117 ** [sqlite3_free()] or [sqlite3_realloc()].
2119 SQLITE_API
void *sqlite3_malloc(int);
2120 SQLITE_API
void *sqlite3_realloc(void*, int);
2121 SQLITE_API
void sqlite3_free(void*);
2124 ** CAPI3REF: Memory Allocator Statistics
2126 ** SQLite provides these two interfaces for reporting on the status
2127 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2128 ** routines, which form the built-in memory allocation subsystem.
2130 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
2131 ** of memory currently outstanding (malloced but not freed).
2132 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
2133 ** value of [sqlite3_memory_used()] since the high-water mark
2134 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
2135 ** [sqlite3_memory_highwater()] include any overhead
2136 ** added by SQLite in its implementation of [sqlite3_malloc()],
2137 ** but not overhead added by the any underlying system library
2138 ** routines that [sqlite3_malloc()] may call.
2140 ** ^The memory high-water mark is reset to the current value of
2141 ** [sqlite3_memory_used()] if and only if the parameter to
2142 ** [sqlite3_memory_highwater()] is true. ^The value returned
2143 ** by [sqlite3_memory_highwater(1)] is the high-water mark
2144 ** prior to the reset.
2146 SQLITE_API sqlite3_int64
sqlite3_memory_used(void);
2147 SQLITE_API sqlite3_int64
sqlite3_memory_highwater(int resetFlag
);
2150 ** CAPI3REF: Pseudo-Random Number Generator
2152 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2153 ** select random [ROWID | ROWIDs] when inserting new records into a table that
2154 ** already uses the largest possible [ROWID]. The PRNG is also used for
2155 ** the build-in random() and randomblob() SQL functions. This interface allows
2156 ** applications to access the same PRNG for other purposes.
2158 ** ^A call to this routine stores N bytes of randomness into buffer P.
2160 ** ^The first time this routine is invoked (either internally or by
2161 ** the application) the PRNG is seeded using randomness obtained
2162 ** from the xRandomness method of the default [sqlite3_vfs] object.
2163 ** ^On all subsequent invocations, the pseudo-randomness is generated
2164 ** internally and without recourse to the [sqlite3_vfs] xRandomness
2167 SQLITE_API
void sqlite3_randomness(int N
, void *P
);
2170 ** CAPI3REF: Compile-Time Authorization Callbacks
2172 ** ^This routine registers an authorizer callback with a particular
2173 ** [database connection], supplied in the first argument.
2174 ** ^The authorizer callback is invoked as SQL statements are being compiled
2175 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2176 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
2177 ** points during the compilation process, as logic is being created
2178 ** to perform various actions, the authorizer callback is invoked to
2179 ** see if those actions are allowed. ^The authorizer callback should
2180 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2181 ** specific action but allow the SQL statement to continue to be
2182 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2183 ** rejected with an error. ^If the authorizer callback returns
2184 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2185 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2186 ** the authorizer will fail with an error message.
2188 ** When the callback returns [SQLITE_OK], that means the operation
2189 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
2190 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
2191 ** authorizer will fail with an error message explaining that
2192 ** access is denied.
2194 ** ^The first parameter to the authorizer callback is a copy of the third
2195 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2196 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
2197 ** the particular action to be authorized. ^The third through sixth parameters
2198 ** to the callback are zero-terminated strings that contain additional
2199 ** details about the action to be authorized.
2201 ** ^If the action code is [SQLITE_READ]
2202 ** and the callback returns [SQLITE_IGNORE] then the
2203 ** [prepared statement] statement is constructed to substitute
2204 ** a NULL value in place of the table column that would have
2205 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2206 ** return can be used to deny an untrusted user access to individual
2207 ** columns of a table.
2208 ** ^If the action code is [SQLITE_DELETE] and the callback returns
2209 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2210 ** [truncate optimization] is disabled and all rows are deleted individually.
2212 ** An authorizer is used when [sqlite3_prepare | preparing]
2213 ** SQL statements from an untrusted source, to ensure that the SQL statements
2214 ** do not try to access data they are not allowed to see, or that they do not
2215 ** try to execute malicious statements that damage the database. For
2216 ** example, an application may allow a user to enter arbitrary
2217 ** SQL queries for evaluation by a database. But the application does
2218 ** not want the user to be able to make arbitrary changes to the
2219 ** database. An authorizer could then be put in place while the
2220 ** user-entered SQL is being [sqlite3_prepare | prepared] that
2221 ** disallows everything except [SELECT] statements.
2223 ** Applications that need to process SQL from untrusted sources
2224 ** might also consider lowering resource limits using [sqlite3_limit()]
2225 ** and limiting database size using the [max_page_count] [PRAGMA]
2226 ** in addition to using an authorizer.
2228 ** ^(Only a single authorizer can be in place on a database connection
2229 ** at a time. Each call to sqlite3_set_authorizer overrides the
2230 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2231 ** The authorizer is disabled by default.
2233 ** The authorizer callback must not do anything that will modify
2234 ** the database connection that invoked the authorizer callback.
2235 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2236 ** database connections for the meaning of "modify" in this paragraph.
2238 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2239 ** statement might be re-prepared during [sqlite3_step()] due to a
2240 ** schema change. Hence, the application should ensure that the
2241 ** correct authorizer callback remains in place during the [sqlite3_step()].
2243 ** ^Note that the authorizer callback is invoked only during
2244 ** [sqlite3_prepare()] or its variants. Authorization is not
2245 ** performed during statement evaluation in [sqlite3_step()], unless
2246 ** as stated in the previous paragraph, sqlite3_step() invokes
2247 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2249 SQLITE_API
int sqlite3_set_authorizer(
2251 int (*xAuth
)(void*,int,const char*,const char*,const char*,const char*),
2256 ** CAPI3REF: Authorizer Return Codes
2258 ** The [sqlite3_set_authorizer | authorizer callback function] must
2259 ** return either [SQLITE_OK] or one of these two constants in order
2260 ** to signal SQLite whether or not the action is permitted. See the
2261 ** [sqlite3_set_authorizer | authorizer documentation] for additional
2264 ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
2265 ** from the [sqlite3_vtab_on_conflict()] interface.
2267 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2268 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2271 ** CAPI3REF: Authorizer Action Codes
2273 ** The [sqlite3_set_authorizer()] interface registers a callback function
2274 ** that is invoked to authorize certain SQL statement actions. The
2275 ** second parameter to the callback is an integer code that specifies
2276 ** what action is being authorized. These are the integer action codes that
2277 ** the authorizer callback may be passed.
2279 ** These action code values signify what kind of operation is to be
2280 ** authorized. The 3rd and 4th parameters to the authorization
2281 ** callback function will be parameters or NULL depending on which of these
2282 ** codes is used as the second parameter. ^(The 5th parameter to the
2283 ** authorizer callback is the name of the database ("main", "temp",
2284 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2285 ** is the name of the inner-most trigger or view that is responsible for
2286 ** the access attempt or NULL if this access attempt is directly from
2287 ** top-level SQL code.
2289 /******************************************* 3rd ************ 4th ***********/
2290 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2291 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2292 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2293 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2294 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2295 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2296 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2297 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2298 #define SQLITE_DELETE 9 /* Table Name NULL */
2299 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2300 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2301 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2302 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2303 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2304 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2305 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2306 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
2307 #define SQLITE_INSERT 18 /* Table Name NULL */
2308 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2309 #define SQLITE_READ 20 /* Table Name Column Name */
2310 #define SQLITE_SELECT 21 /* NULL NULL */
2311 #define SQLITE_TRANSACTION 22 /* Operation NULL */
2312 #define SQLITE_UPDATE 23 /* Table Name Column Name */
2313 #define SQLITE_ATTACH 24 /* Filename NULL */
2314 #define SQLITE_DETACH 25 /* Database Name NULL */
2315 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2316 #define SQLITE_REINDEX 27 /* Index Name NULL */
2317 #define SQLITE_ANALYZE 28 /* Table Name NULL */
2318 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2319 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2320 #define SQLITE_FUNCTION 31 /* NULL Function Name */
2321 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2322 #define SQLITE_COPY 0 /* No longer used */
2325 ** CAPI3REF: Tracing And Profiling Functions
2327 ** These routines register callback functions that can be used for
2328 ** tracing and profiling the execution of SQL statements.
2330 ** ^The callback function registered by sqlite3_trace() is invoked at
2331 ** various times when an SQL statement is being run by [sqlite3_step()].
2332 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2333 ** SQL statement text as the statement first begins executing.
2334 ** ^(Additional sqlite3_trace() callbacks might occur
2335 ** as each triggered subprogram is entered. The callbacks for triggers
2336 ** contain a UTF-8 SQL comment that identifies the trigger.)^
2338 ** ^The callback function registered by sqlite3_profile() is invoked
2339 ** as each SQL statement finishes. ^The profile callback contains
2340 ** the original statement text and an estimate of wall-clock time
2341 ** of how long that statement took to run. ^The profile callback
2342 ** time is in units of nanoseconds, however the current implementation
2343 ** is only capable of millisecond resolution so the six least significant
2344 ** digits in the time are meaningless. Future versions of SQLite
2345 ** might provide greater resolution on the profiler callback. The
2346 ** sqlite3_profile() function is considered experimental and is
2347 ** subject to change in future versions of SQLite.
2349 SQLITE_API
void *sqlite3_trace(sqlite3
*, void(*xTrace
)(void*,const char*), void*);
2350 SQLITE_API SQLITE_EXPERIMENTAL
void *sqlite3_profile(sqlite3
*,
2351 void(*xProfile
)(void*,const char*,sqlite3_uint64
), void*);
2354 ** CAPI3REF: Query Progress Callbacks
2356 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2357 ** function X to be invoked periodically during long running calls to
2358 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2359 ** database connection D. An example use for this
2360 ** interface is to keep a GUI updated during a large query.
2362 ** ^The parameter P is passed through as the only parameter to the
2363 ** callback function X. ^The parameter N is the number of
2364 ** [virtual machine instructions] that are evaluated between successive
2365 ** invocations of the callback X.
2367 ** ^Only a single progress handler may be defined at one time per
2368 ** [database connection]; setting a new progress handler cancels the
2369 ** old one. ^Setting parameter X to NULL disables the progress handler.
2370 ** ^The progress handler is also disabled by setting N to a value less
2373 ** ^If the progress callback returns non-zero, the operation is
2374 ** interrupted. This feature can be used to implement a
2375 ** "Cancel" button on a GUI progress dialog box.
2377 ** The progress handler callback must not do anything that will modify
2378 ** the database connection that invoked the progress handler.
2379 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2380 ** database connections for the meaning of "modify" in this paragraph.
2383 SQLITE_API
void sqlite3_progress_handler(sqlite3
*, int, int(*)(void*), void*);
2386 ** CAPI3REF: Opening A New Database Connection
2388 ** ^These routines open an SQLite database file as specified by the
2389 ** filename argument. ^The filename argument is interpreted as UTF-8 for
2390 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2391 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
2392 ** returned in *ppDb, even if an error occurs. The only exception is that
2393 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2394 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2395 ** object.)^ ^(If the database is opened (and/or created) successfully, then
2396 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
2397 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2398 ** an English language description of the error following a failure of any
2399 ** of the sqlite3_open() routines.
2401 ** ^The default encoding for the database will be UTF-8 if
2402 ** sqlite3_open() or sqlite3_open_v2() is called and
2403 ** UTF-16 in the native byte order if sqlite3_open16() is used.
2405 ** Whether or not an error occurs when it is opened, resources
2406 ** associated with the [database connection] handle should be released by
2407 ** passing it to [sqlite3_close()] when it is no longer required.
2409 ** The sqlite3_open_v2() interface works like sqlite3_open()
2410 ** except that it accepts two additional parameters for additional control
2411 ** over the new database connection. ^(The flags parameter to
2412 ** sqlite3_open_v2() can take one of
2413 ** the following three values, optionally combined with the
2414 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
2415 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
2418 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
2419 ** <dd>The database is opened in read-only mode. If the database does not
2420 ** already exist, an error is returned.</dd>)^
2422 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
2423 ** <dd>The database is opened for reading and writing if possible, or reading
2424 ** only if the file is write protected by the operating system. In either
2425 ** case the database must already exist, otherwise an error is returned.</dd>)^
2427 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
2428 ** <dd>The database is opened for reading and writing, and is created if
2429 ** it does not already exist. This is the behavior that is always used for
2430 ** sqlite3_open() and sqlite3_open16().</dd>)^
2433 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
2434 ** combinations shown above optionally combined with other
2435 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
2436 ** then the behavior is undefined.
2438 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
2439 ** opens in the multi-thread [threading mode] as long as the single-thread
2440 ** mode has not been set at compile-time or start-time. ^If the
2441 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2442 ** in the serialized [threading mode] unless single-thread was
2443 ** previously selected at compile-time or start-time.
2444 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
2445 ** eligible to use [shared cache mode], regardless of whether or not shared
2446 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
2447 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2448 ** participate in [shared cache mode] even if it is enabled.
2450 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
2451 ** [sqlite3_vfs] object that defines the operating system interface that
2452 ** the new database connection should use. ^If the fourth parameter is
2453 ** a NULL pointer then the default [sqlite3_vfs] object is used.
2455 ** ^If the filename is ":memory:", then a private, temporary in-memory database
2456 ** is created for the connection. ^This in-memory database will vanish when
2457 ** the database connection is closed. Future versions of SQLite might
2458 ** make use of additional special filenames that begin with the ":" character.
2459 ** It is recommended that when a database filename actually does begin with
2460 ** a ":" character you should prefix the filename with a pathname such as
2461 ** "./" to avoid ambiguity.
2463 ** ^If the filename is an empty string, then a private, temporary
2464 ** on-disk database will be created. ^This private database will be
2465 ** automatically deleted as soon as the database connection is closed.
2467 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
2469 ** ^If [URI filename] interpretation is enabled, and the filename argument
2470 ** begins with "file:", then the filename is interpreted as a URI. ^URI
2471 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
2472 ** set in the fourth argument to sqlite3_open_v2(), or if it has
2473 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
2474 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
2475 ** As of SQLite version 3.7.7, URI filename interpretation is turned off
2476 ** by default, but future releases of SQLite might enable URI filename
2477 ** interpretation by default. See "[URI filenames]" for additional
2480 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
2481 ** authority, then it must be either an empty string or the string
2482 ** "localhost". ^If the authority is not an empty string or "localhost", an
2483 ** error is returned to the caller. ^The fragment component of a URI, if
2484 ** present, is ignored.
2486 ** ^SQLite uses the path component of the URI as the name of the disk file
2487 ** which contains the database. ^If the path begins with a '/' character,
2488 ** then it is interpreted as an absolute path. ^If the path does not begin
2489 ** with a '/' (meaning that the authority section is omitted from the URI)
2490 ** then the path is interpreted as a relative path.
2491 ** ^On windows, the first component of an absolute path
2492 ** is a drive specification (e.g. "C:").
2494 ** [[core URI query parameters]]
2495 ** The query component of a URI may contain parameters that are interpreted
2496 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
2497 ** SQLite interprets the following three query parameters:
2500 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
2501 ** a VFS object that provides the operating system interface that should
2502 ** be used to access the database file on disk. ^If this option is set to
2503 ** an empty string the default VFS object is used. ^Specifying an unknown
2504 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
2505 ** present, then the VFS specified by the option takes precedence over
2506 ** the value passed as the fourth parameter to sqlite3_open_v2().
2508 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or
2509 ** "rwc". Attempting to set it to any other value is an error)^.
2510 ** ^If "ro" is specified, then the database is opened for read-only
2511 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
2512 ** third argument to sqlite3_prepare_v2(). ^If the mode option is set to
2513 ** "rw", then the database is opened for read-write (but not create)
2514 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
2515 ** been set. ^Value "rwc" is equivalent to setting both
2516 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is
2517 ** used, it is an error to specify a value for the mode parameter that is
2518 ** less restrictive than that specified by the flags passed as the third
2521 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
2522 ** "private". ^Setting it to "shared" is equivalent to setting the
2523 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
2524 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
2525 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
2526 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
2527 ** a URI filename, its value overrides any behaviour requested by setting
2528 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
2531 ** ^Specifying an unknown parameter in the query component of a URI is not an
2532 ** error. Future versions of SQLite might understand additional query
2533 ** parameters. See "[query parameters with special meaning to SQLite]" for
2534 ** additional information.
2536 ** [[URI filename examples]] <h3>URI filename examples</h3>
2538 ** <table border="1" align=center cellpadding=5>
2539 ** <tr><th> URI filenames <th> Results
2540 ** <tr><td> file:data.db <td>
2541 ** Open the file "data.db" in the current directory.
2542 ** <tr><td> file:/home/fred/data.db<br>
2543 ** file:///home/fred/data.db <br>
2544 ** file://localhost/home/fred/data.db <br> <td>
2545 ** Open the database file "/home/fred/data.db".
2546 ** <tr><td> file://darkstar/home/fred/data.db <td>
2547 ** An error. "darkstar" is not a recognized authority.
2548 ** <tr><td style="white-space:nowrap">
2549 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
2550 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
2551 ** C:. Note that the %20 escaping in this example is not strictly
2552 ** necessary - space characters can be used literally
2553 ** in URI filenames.
2554 ** <tr><td> file:data.db?mode=ro&cache=private <td>
2555 ** Open file "data.db" in the current directory for read-only access.
2556 ** Regardless of whether or not shared-cache mode is enabled by
2557 ** default, use a private cache.
2558 ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
2559 ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
2560 ** <tr><td> file:data.db?mode=readonly <td>
2561 ** An error. "readonly" is not a valid option for the "mode" parameter.
2564 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
2565 ** query components of a URI. A hexadecimal escape sequence consists of a
2566 ** percent sign - "%" - followed by exactly two hexadecimal digits
2567 ** specifying an octet value. ^Before the path or query components of a
2568 ** URI filename are interpreted, they are encoded using UTF-8 and all
2569 ** hexadecimal escape sequences replaced by a single byte containing the
2570 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
2571 ** the results are undefined.
2573 ** <b>Note to Windows users:</b> The encoding used for the filename argument
2574 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
2575 ** codepage is currently defined. Filenames containing international
2576 ** characters must be converted to UTF-8 prior to passing them into
2577 ** sqlite3_open() or sqlite3_open_v2().
2579 SQLITE_API
int sqlite3_open(
2580 const char *filename
, /* Database filename (UTF-8) */
2581 sqlite3
**ppDb
/* OUT: SQLite db handle */
2583 SQLITE_API
int sqlite3_open16(
2584 const void *filename
, /* Database filename (UTF-16) */
2585 sqlite3
**ppDb
/* OUT: SQLite db handle */
2587 SQLITE_API
int sqlite3_open_v2(
2588 const char *filename
, /* Database filename (UTF-8) */
2589 sqlite3
**ppDb
, /* OUT: SQLite db handle */
2590 int flags
, /* Flags */
2591 const char *zVfs
/* Name of VFS module to use */
2595 ** CAPI3REF: Obtain Values For URI Parameters
2597 ** This is a utility routine, useful to VFS implementations, that checks
2598 ** to see if a database file was a URI that contained a specific query
2599 ** parameter, and if so obtains the value of the query parameter.
2601 ** The zFilename argument is the filename pointer passed into the xOpen()
2602 ** method of a VFS implementation. The zParam argument is the name of the
2603 ** query parameter we seek. This routine returns the value of the zParam
2604 ** parameter if it exists. If the parameter does not exist, this routine
2605 ** returns a NULL pointer.
2607 ** If the zFilename argument to this function is not a pointer that SQLite
2608 ** passed into the xOpen VFS method, then the behavior of this routine
2609 ** is undefined and probably undesirable.
2611 SQLITE_API
const char *sqlite3_uri_parameter(const char *zFilename
, const char *zParam
);
2615 ** CAPI3REF: Error Codes And Messages
2617 ** ^The sqlite3_errcode() interface returns the numeric [result code] or
2618 ** [extended result code] for the most recent failed sqlite3_* API call
2619 ** associated with a [database connection]. If a prior API call failed
2620 ** but the most recent API call succeeded, the return value from
2621 ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode()
2622 ** interface is the same except that it always returns the
2623 ** [extended result code] even when extended result codes are
2626 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
2627 ** text that describes the error, as either UTF-8 or UTF-16 respectively.
2628 ** ^(Memory to hold the error message string is managed internally.
2629 ** The application does not need to worry about freeing the result.
2630 ** However, the error string might be overwritten or deallocated by
2631 ** subsequent calls to other SQLite interface functions.)^
2633 ** When the serialized [threading mode] is in use, it might be the
2634 ** case that a second error occurs on a separate thread in between
2635 ** the time of the first error and the call to these interfaces.
2636 ** When that happens, the second error will be reported since these
2637 ** interfaces always report the most recent result. To avoid
2638 ** this, each thread can obtain exclusive use of the [database connection] D
2639 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
2640 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
2641 ** all calls to the interfaces listed here are completed.
2643 ** If an interface fails with SQLITE_MISUSE, that means the interface
2644 ** was invoked incorrectly by the application. In that case, the
2645 ** error code and message may or may not be set.
2647 SQLITE_API
int sqlite3_errcode(sqlite3
*db
);
2648 SQLITE_API
int sqlite3_extended_errcode(sqlite3
*db
);
2649 SQLITE_API
const char *sqlite3_errmsg(sqlite3
*);
2650 SQLITE_API
const void *sqlite3_errmsg16(sqlite3
*);
2653 ** CAPI3REF: SQL Statement Object
2654 ** KEYWORDS: {prepared statement} {prepared statements}
2656 ** An instance of this object represents a single SQL statement.
2657 ** This object is variously known as a "prepared statement" or a
2658 ** "compiled SQL statement" or simply as a "statement".
2660 ** The life of a statement object goes something like this:
2663 ** <li> Create the object using [sqlite3_prepare_v2()] or a related
2665 ** <li> Bind values to [host parameters] using the sqlite3_bind_*()
2667 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
2668 ** <li> Reset the statement using [sqlite3_reset()] then go back
2669 ** to step 2. Do this zero or more times.
2670 ** <li> Destroy the object using [sqlite3_finalize()].
2673 ** Refer to documentation on individual methods above for additional
2676 typedef struct sqlite3_stmt sqlite3_stmt
;
2679 ** CAPI3REF: Run-time Limits
2681 ** ^(This interface allows the size of various constructs to be limited
2682 ** on a connection by connection basis. The first parameter is the
2683 ** [database connection] whose limit is to be set or queried. The
2684 ** second parameter is one of the [limit categories] that define a
2685 ** class of constructs to be size limited. The third parameter is the
2686 ** new limit for that construct.)^
2688 ** ^If the new limit is a negative number, the limit is unchanged.
2689 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
2690 ** [limits | hard upper bound]
2691 ** set at compile-time by a C preprocessor macro called
2692 ** [limits | SQLITE_MAX_<i>NAME</i>].
2693 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
2694 ** ^Attempts to increase a limit above its hard upper bound are
2695 ** silently truncated to the hard upper bound.
2697 ** ^Regardless of whether or not the limit was changed, the
2698 ** [sqlite3_limit()] interface returns the prior value of the limit.
2699 ** ^Hence, to find the current value of a limit without changing it,
2700 ** simply invoke this interface with the third parameter set to -1.
2702 ** Run-time limits are intended for use in applications that manage
2703 ** both their own internal database and also databases that are controlled
2704 ** by untrusted external sources. An example application might be a
2705 ** web browser that has its own databases for storing history and
2706 ** separate databases controlled by JavaScript applications downloaded
2707 ** off the Internet. The internal databases can be given the
2708 ** large, default limits. Databases managed by external sources can
2709 ** be given much smaller limits designed to prevent a denial of service
2710 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
2711 ** interface to further control untrusted SQL. The size of the database
2712 ** created by an untrusted script can be contained using the
2713 ** [max_page_count] [PRAGMA].
2715 ** New run-time limit categories may be added in future releases.
2717 SQLITE_API
int sqlite3_limit(sqlite3
*, int id
, int newVal
);
2720 ** CAPI3REF: Run-Time Limit Categories
2721 ** KEYWORDS: {limit category} {*limit categories}
2723 ** These constants define various performance limits
2724 ** that can be lowered at run-time using [sqlite3_limit()].
2725 ** The synopsis of the meanings of the various limits is shown below.
2726 ** Additional information is available at [limits | Limits in SQLite].
2729 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
2730 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
2732 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
2733 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
2735 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
2736 ** <dd>The maximum number of columns in a table definition or in the
2737 ** result set of a [SELECT] or the maximum number of columns in an index
2738 ** or in an ORDER BY or GROUP BY clause.</dd>)^
2740 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
2741 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
2743 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
2744 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
2746 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
2747 ** <dd>The maximum number of instructions in a virtual machine program
2748 ** used to implement an SQL statement. This limit is not currently
2749 ** enforced, though that might be added in some future release of
2752 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
2753 ** <dd>The maximum number of arguments on a function.</dd>)^
2755 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
2756 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
2758 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
2759 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
2760 ** <dd>The maximum length of the pattern argument to the [LIKE] or
2761 ** [GLOB] operators.</dd>)^
2763 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
2764 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
2765 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
2767 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
2768 ** <dd>The maximum depth of recursion for triggers.</dd>)^
2771 #define SQLITE_LIMIT_LENGTH 0
2772 #define SQLITE_LIMIT_SQL_LENGTH 1
2773 #define SQLITE_LIMIT_COLUMN 2
2774 #define SQLITE_LIMIT_EXPR_DEPTH 3
2775 #define SQLITE_LIMIT_COMPOUND_SELECT 4
2776 #define SQLITE_LIMIT_VDBE_OP 5
2777 #define SQLITE_LIMIT_FUNCTION_ARG 6
2778 #define SQLITE_LIMIT_ATTACHED 7
2779 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
2780 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
2781 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
2784 ** CAPI3REF: Compiling An SQL Statement
2785 ** KEYWORDS: {SQL statement compiler}
2787 ** To execute an SQL query, it must first be compiled into a byte-code
2788 ** program using one of these routines.
2790 ** The first argument, "db", is a [database connection] obtained from a
2791 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
2792 ** [sqlite3_open16()]. The database connection must not have been closed.
2794 ** The second argument, "zSql", is the statement to be compiled, encoded
2795 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
2796 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
2799 ** ^If the nByte argument is less than zero, then zSql is read up to the
2800 ** first zero terminator. ^If nByte is non-negative, then it is the maximum
2801 ** number of bytes read from zSql. ^When nByte is non-negative, the
2802 ** zSql string ends at either the first '\000' or '\u0000' character or
2803 ** the nByte-th byte, whichever comes first. If the caller knows
2804 ** that the supplied string is nul-terminated, then there is a small
2805 ** performance advantage to be gained by passing an nByte parameter that
2806 ** is equal to the number of bytes in the input string <i>including</i>
2807 ** the nul-terminator bytes as this saves SQLite from having to
2808 ** make a copy of the input string.
2810 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
2811 ** past the end of the first SQL statement in zSql. These routines only
2812 ** compile the first statement in zSql, so *pzTail is left pointing to
2813 ** what remains uncompiled.
2815 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
2816 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
2817 ** to NULL. ^If the input text contains no SQL (if the input is an empty
2818 ** string or a comment) then *ppStmt is set to NULL.
2819 ** The calling procedure is responsible for deleting the compiled
2820 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
2821 ** ppStmt may not be NULL.
2823 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
2824 ** otherwise an [error code] is returned.
2826 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
2827 ** recommended for all new programs. The two older interfaces are retained
2828 ** for backwards compatibility, but their use is discouraged.
2829 ** ^In the "v2" interfaces, the prepared statement
2830 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
2831 ** original SQL text. This causes the [sqlite3_step()] interface to
2832 ** behave differently in three ways:
2836 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
2837 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
2838 ** statement and try to run it again.
2842 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
2843 ** [error codes] or [extended error codes]. ^The legacy behavior was that
2844 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
2845 ** and the application would have to make a second call to [sqlite3_reset()]
2846 ** in order to find the underlying cause of the problem. With the "v2" prepare
2847 ** interfaces, the underlying reason for the error is returned immediately.
2851 ** ^If the specific value bound to [parameter | host parameter] in the
2852 ** WHERE clause might influence the choice of query plan for a statement,
2853 ** then the statement will be automatically recompiled, as if there had been
2854 ** a schema change, on the first [sqlite3_step()] call following any change
2855 ** to the [sqlite3_bind_text | bindings] of that [parameter].
2856 ** ^The specific value of WHERE-clause [parameter] might influence the
2857 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
2858 ** or [GLOB] operator or if the parameter is compared to an indexed column
2859 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
2864 SQLITE_API
int sqlite3_prepare(
2865 sqlite3
*db
, /* Database handle */
2866 const char *zSql
, /* SQL statement, UTF-8 encoded */
2867 int nByte
, /* Maximum length of zSql in bytes. */
2868 sqlite3_stmt
**ppStmt
, /* OUT: Statement handle */
2869 const char **pzTail
/* OUT: Pointer to unused portion of zSql */
2871 SQLITE_API
int sqlite3_prepare_v2(
2872 sqlite3
*db
, /* Database handle */
2873 const char *zSql
, /* SQL statement, UTF-8 encoded */
2874 int nByte
, /* Maximum length of zSql in bytes. */
2875 sqlite3_stmt
**ppStmt
, /* OUT: Statement handle */
2876 const char **pzTail
/* OUT: Pointer to unused portion of zSql */
2878 SQLITE_API
int sqlite3_prepare16(
2879 sqlite3
*db
, /* Database handle */
2880 const void *zSql
, /* SQL statement, UTF-16 encoded */
2881 int nByte
, /* Maximum length of zSql in bytes. */
2882 sqlite3_stmt
**ppStmt
, /* OUT: Statement handle */
2883 const void **pzTail
/* OUT: Pointer to unused portion of zSql */
2885 SQLITE_API
int sqlite3_prepare16_v2(
2886 sqlite3
*db
, /* Database handle */
2887 const void *zSql
, /* SQL statement, UTF-16 encoded */
2888 int nByte
, /* Maximum length of zSql in bytes. */
2889 sqlite3_stmt
**ppStmt
, /* OUT: Statement handle */
2890 const void **pzTail
/* OUT: Pointer to unused portion of zSql */
2894 ** CAPI3REF: Retrieving Statement SQL
2896 ** ^This interface can be used to retrieve a saved copy of the original
2897 ** SQL text used to create a [prepared statement] if that statement was
2898 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
2900 SQLITE_API
const char *sqlite3_sql(sqlite3_stmt
*pStmt
);
2903 ** CAPI3REF: Determine If An SQL Statement Writes The Database
2905 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
2906 ** and only if the [prepared statement] X makes no direct changes to
2907 ** the content of the database file.
2909 ** Note that [application-defined SQL functions] or
2910 ** [virtual tables] might change the database indirectly as a side effect.
2911 ** ^(For example, if an application defines a function "eval()" that
2912 ** calls [sqlite3_exec()], then the following SQL statement would
2913 ** change the database file through side-effects:
2915 ** <blockquote><pre>
2916 ** SELECT eval('DELETE FROM t1') FROM t2;
2917 ** </pre></blockquote>
2919 ** But because the [SELECT] statement does not change the database file
2920 ** directly, sqlite3_stmt_readonly() would still return true.)^
2922 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
2923 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
2924 ** since the statements themselves do not actually modify the database but
2925 ** rather they control the timing of when other statements modify the
2926 ** database. ^The [ATTACH] and [DETACH] statements also cause
2927 ** sqlite3_stmt_readonly() to return true since, while those statements
2928 ** change the configuration of a database connection, they do not make
2929 ** changes to the content of the database files on disk.
2931 SQLITE_API
int sqlite3_stmt_readonly(sqlite3_stmt
*pStmt
);
2934 ** CAPI3REF: Dynamically Typed Value Object
2935 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
2937 ** SQLite uses the sqlite3_value object to represent all values
2938 ** that can be stored in a database table. SQLite uses dynamic typing
2939 ** for the values it stores. ^Values stored in sqlite3_value objects
2940 ** can be integers, floating point values, strings, BLOBs, or NULL.
2942 ** An sqlite3_value object may be either "protected" or "unprotected".
2943 ** Some interfaces require a protected sqlite3_value. Other interfaces
2944 ** will accept either a protected or an unprotected sqlite3_value.
2945 ** Every interface that accepts sqlite3_value arguments specifies
2946 ** whether or not it requires a protected sqlite3_value.
2948 ** The terms "protected" and "unprotected" refer to whether or not
2949 ** a mutex is held. An internal mutex is held for a protected
2950 ** sqlite3_value object but no mutex is held for an unprotected
2951 ** sqlite3_value object. If SQLite is compiled to be single-threaded
2952 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
2953 ** or if SQLite is run in one of reduced mutex modes
2954 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
2955 ** then there is no distinction between protected and unprotected
2956 ** sqlite3_value objects and they can be used interchangeably. However,
2957 ** for maximum code portability it is recommended that applications
2958 ** still make the distinction between protected and unprotected
2959 ** sqlite3_value objects even when not strictly required.
2961 ** ^The sqlite3_value objects that are passed as parameters into the
2962 ** implementation of [application-defined SQL functions] are protected.
2963 ** ^The sqlite3_value object returned by
2964 ** [sqlite3_column_value()] is unprotected.
2965 ** Unprotected sqlite3_value objects may only be used with
2966 ** [sqlite3_result_value()] and [sqlite3_bind_value()].
2967 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
2968 ** interfaces require protected sqlite3_value objects.
2970 typedef struct Mem sqlite3_value
;
2973 ** CAPI3REF: SQL Function Context Object
2975 ** The context in which an SQL function executes is stored in an
2976 ** sqlite3_context object. ^A pointer to an sqlite3_context object
2977 ** is always first parameter to [application-defined SQL functions].
2978 ** The application-defined SQL function implementation will pass this
2979 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
2980 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
2981 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
2982 ** and/or [sqlite3_set_auxdata()].
2984 typedef struct sqlite3_context sqlite3_context
;
2987 ** CAPI3REF: Binding Values To Prepared Statements
2988 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
2989 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
2991 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
2992 ** literals may be replaced by a [parameter] that matches one of following
3003 ** In the templates above, NNN represents an integer literal,
3004 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
3005 ** parameters (also called "host parameter names" or "SQL parameters")
3006 ** can be set using the sqlite3_bind_*() routines defined here.
3008 ** ^The first argument to the sqlite3_bind_*() routines is always
3009 ** a pointer to the [sqlite3_stmt] object returned from
3010 ** [sqlite3_prepare_v2()] or its variants.
3012 ** ^The second argument is the index of the SQL parameter to be set.
3013 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
3014 ** SQL parameter is used more than once, second and subsequent
3015 ** occurrences have the same index as the first occurrence.
3016 ** ^The index for named parameters can be looked up using the
3017 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
3018 ** for "?NNN" parameters is the value of NNN.
3019 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
3020 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3022 ** ^The third argument is the value to bind to the parameter.
3024 ** ^(In those routines that have a fourth argument, its value is the
3025 ** number of bytes in the parameter. To be clear: the value is the
3026 ** number of <u>bytes</u> in the value, not the number of characters.)^
3027 ** ^If the fourth parameter is negative, the length of the string is
3028 ** the number of bytes up to the first zero terminator.
3029 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3030 ** or sqlite3_bind_text16() then that parameter must be the byte offset
3031 ** where the NUL terminator would occur assuming the string were NUL
3032 ** terminated. If any NUL characters occur at byte offsets less than
3033 ** the value of the fourth parameter then the resulting string value will
3034 ** contain embedded NULs. The result of expressions involving strings
3035 ** with embedded NULs is undefined.
3037 ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
3038 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
3039 ** string after SQLite has finished with it. ^The destructor is called
3040 ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
3041 ** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
3042 ** ^If the fifth argument is
3043 ** the special value [SQLITE_STATIC], then SQLite assumes that the
3044 ** information is in static, unmanaged space and does not need to be freed.
3045 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3046 ** SQLite makes its own private copy of the data immediately, before
3047 ** the sqlite3_bind_*() routine returns.
3049 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3050 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
3051 ** (just an integer to hold its size) while it is being processed.
3052 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
3053 ** content is later written using
3054 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
3055 ** ^A negative value for the zeroblob results in a zero-length BLOB.
3057 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3058 ** for the [prepared statement] or with a prepared statement for which
3059 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3060 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
3061 ** routine is passed a [prepared statement] that has been finalized, the
3062 ** result is undefined and probably harmful.
3064 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3065 ** ^Unbound parameters are interpreted as NULL.
3067 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3068 ** [error code] if anything goes wrong.
3069 ** ^[SQLITE_RANGE] is returned if the parameter
3070 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
3072 ** See also: [sqlite3_bind_parameter_count()],
3073 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3075 SQLITE_API
int sqlite3_bind_blob(sqlite3_stmt
*, int, const void*, int n
, void(*)(void*));
3076 SQLITE_API
int sqlite3_bind_double(sqlite3_stmt
*, int, double);
3077 SQLITE_API
int sqlite3_bind_int(sqlite3_stmt
*, int, int);
3078 SQLITE_API
int sqlite3_bind_int64(sqlite3_stmt
*, int, sqlite3_int64
);
3079 SQLITE_API
int sqlite3_bind_null(sqlite3_stmt
*, int);
3080 SQLITE_API
int sqlite3_bind_text(sqlite3_stmt
*, int, const char*, int n
, void(*)(void*));
3081 SQLITE_API
int sqlite3_bind_text16(sqlite3_stmt
*, int, const void*, int, void(*)(void*));
3082 SQLITE_API
int sqlite3_bind_value(sqlite3_stmt
*, int, const sqlite3_value
*);
3083 SQLITE_API
int sqlite3_bind_zeroblob(sqlite3_stmt
*, int, int n
);
3086 ** CAPI3REF: Number Of SQL Parameters
3088 ** ^This routine can be used to find the number of [SQL parameters]
3089 ** in a [prepared statement]. SQL parameters are tokens of the
3090 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3091 ** placeholders for values that are [sqlite3_bind_blob | bound]
3092 ** to the parameters at a later time.
3094 ** ^(This routine actually returns the index of the largest (rightmost)
3095 ** parameter. For all forms except ?NNN, this will correspond to the
3096 ** number of unique parameters. If parameters of the ?NNN form are used,
3097 ** there may be gaps in the list.)^
3099 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3100 ** [sqlite3_bind_parameter_name()], and
3101 ** [sqlite3_bind_parameter_index()].
3103 SQLITE_API
int sqlite3_bind_parameter_count(sqlite3_stmt
*);
3106 ** CAPI3REF: Name Of A Host Parameter
3108 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
3109 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
3110 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3111 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3113 ** In other words, the initial ":" or "$" or "@" or "?"
3114 ** is included as part of the name.)^
3115 ** ^Parameters of the form "?" without a following integer have no name
3116 ** and are referred to as "nameless" or "anonymous parameters".
3118 ** ^The first host parameter has an index of 1, not 0.
3120 ** ^If the value N is out of range or if the N-th parameter is
3121 ** nameless, then NULL is returned. ^The returned string is
3122 ** always in UTF-8 encoding even if the named parameter was
3123 ** originally specified as UTF-16 in [sqlite3_prepare16()] or
3124 ** [sqlite3_prepare16_v2()].
3126 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3127 ** [sqlite3_bind_parameter_count()], and
3128 ** [sqlite3_bind_parameter_index()].
3130 SQLITE_API
const char *sqlite3_bind_parameter_name(sqlite3_stmt
*, int);
3133 ** CAPI3REF: Index Of A Parameter With A Given Name
3135 ** ^Return the index of an SQL parameter given its name. ^The
3136 ** index value returned is suitable for use as the second
3137 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
3138 ** is returned if no matching parameter is found. ^The parameter
3139 ** name must be given in UTF-8 even if the original statement
3140 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3142 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3143 ** [sqlite3_bind_parameter_count()], and
3144 ** [sqlite3_bind_parameter_index()].
3146 SQLITE_API
int sqlite3_bind_parameter_index(sqlite3_stmt
*, const char *zName
);
3149 ** CAPI3REF: Reset All Bindings On A Prepared Statement
3151 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3152 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3153 ** ^Use this routine to reset all host parameters to NULL.
3155 SQLITE_API
int sqlite3_clear_bindings(sqlite3_stmt
*);
3158 ** CAPI3REF: Number Of Columns In A Result Set
3160 ** ^Return the number of columns in the result set returned by the
3161 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3162 ** statement that does not return data (for example an [UPDATE]).
3164 ** See also: [sqlite3_data_count()]
3166 SQLITE_API
int sqlite3_column_count(sqlite3_stmt
*pStmt
);
3169 ** CAPI3REF: Column Names In A Result Set
3171 ** ^These routines return the name assigned to a particular column
3172 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
3173 ** interface returns a pointer to a zero-terminated UTF-8 string
3174 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
3175 ** UTF-16 string. ^The first parameter is the [prepared statement]
3176 ** that implements the [SELECT] statement. ^The second parameter is the
3177 ** column number. ^The leftmost column is number 0.
3179 ** ^The returned string pointer is valid until either the [prepared statement]
3180 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3181 ** reprepared by the first call to [sqlite3_step()] for a particular run
3182 ** or until the next call to
3183 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3185 ** ^If sqlite3_malloc() fails during the processing of either routine
3186 ** (for example during a conversion from UTF-8 to UTF-16) then a
3187 ** NULL pointer is returned.
3189 ** ^The name of a result column is the value of the "AS" clause for
3190 ** that column, if there is an AS clause. If there is no AS clause
3191 ** then the name of the column is unspecified and may change from
3192 ** one release of SQLite to the next.
3194 SQLITE_API
const char *sqlite3_column_name(sqlite3_stmt
*, int N
);
3195 SQLITE_API
const void *sqlite3_column_name16(sqlite3_stmt
*, int N
);
3198 ** CAPI3REF: Source Of Data In A Query Result
3200 ** ^These routines provide a means to determine the database, table, and
3201 ** table column that is the origin of a particular result column in
3202 ** [SELECT] statement.
3203 ** ^The name of the database or table or column can be returned as
3204 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
3205 ** the database name, the _table_ routines return the table name, and
3206 ** the origin_ routines return the column name.
3207 ** ^The returned string is valid until the [prepared statement] is destroyed
3208 ** using [sqlite3_finalize()] or until the statement is automatically
3209 ** reprepared by the first call to [sqlite3_step()] for a particular run
3210 ** or until the same information is requested
3211 ** again in a different encoding.
3213 ** ^The names returned are the original un-aliased names of the
3214 ** database, table, and column.
3216 ** ^The first argument to these interfaces is a [prepared statement].
3217 ** ^These functions return information about the Nth result column returned by
3218 ** the statement, where N is the second function argument.
3219 ** ^The left-most column is column 0 for these routines.
3221 ** ^If the Nth column returned by the statement is an expression or
3222 ** subquery and is not a column value, then all of these functions return
3223 ** NULL. ^These routine might also return NULL if a memory allocation error
3224 ** occurs. ^Otherwise, they return the name of the attached database, table,
3225 ** or column that query result column was extracted from.
3227 ** ^As with all other SQLite APIs, those whose names end with "16" return
3228 ** UTF-16 encoded strings and the other functions return UTF-8.
3230 ** ^These APIs are only available if the library was compiled with the
3231 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3233 ** If two or more threads call one or more of these routines against the same
3234 ** prepared statement and column at the same time then the results are
3237 ** If two or more threads call one or more
3238 ** [sqlite3_column_database_name | column metadata interfaces]
3239 ** for the same [prepared statement] and result column
3240 ** at the same time then the results are undefined.
3242 SQLITE_API
const char *sqlite3_column_database_name(sqlite3_stmt
*,int);
3243 SQLITE_API
const void *sqlite3_column_database_name16(sqlite3_stmt
*,int);
3244 SQLITE_API
const char *sqlite3_column_table_name(sqlite3_stmt
*,int);
3245 SQLITE_API
const void *sqlite3_column_table_name16(sqlite3_stmt
*,int);
3246 SQLITE_API
const char *sqlite3_column_origin_name(sqlite3_stmt
*,int);
3247 SQLITE_API
const void *sqlite3_column_origin_name16(sqlite3_stmt
*,int);
3250 ** CAPI3REF: Declared Datatype Of A Query Result
3252 ** ^(The first parameter is a [prepared statement].
3253 ** If this statement is a [SELECT] statement and the Nth column of the
3254 ** returned result set of that [SELECT] is a table column (not an
3255 ** expression or subquery) then the declared type of the table
3256 ** column is returned.)^ ^If the Nth column of the result set is an
3257 ** expression or subquery, then a NULL pointer is returned.
3258 ** ^The returned string is always UTF-8 encoded.
3260 ** ^(For example, given the database schema:
3262 ** CREATE TABLE t1(c1 VARIANT);
3264 ** and the following statement to be compiled:
3266 ** SELECT c1 + 1, c1 FROM t1;
3268 ** this routine would return the string "VARIANT" for the second result
3269 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
3271 ** ^SQLite uses dynamic run-time typing. ^So just because a column
3272 ** is declared to contain a particular type does not mean that the
3273 ** data stored in that column is of the declared type. SQLite is
3274 ** strongly typed, but the typing is dynamic not static. ^Type
3275 ** is associated with individual values, not with the containers
3276 ** used to hold those values.
3278 SQLITE_API
const char *sqlite3_column_decltype(sqlite3_stmt
*,int);
3279 SQLITE_API
const void *sqlite3_column_decltype16(sqlite3_stmt
*,int);
3282 ** CAPI3REF: Evaluate An SQL Statement
3284 ** After a [prepared statement] has been prepared using either
3285 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3286 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3287 ** must be called one or more times to evaluate the statement.
3289 ** The details of the behavior of the sqlite3_step() interface depend
3290 ** on whether the statement was prepared using the newer "v2" interface
3291 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3292 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
3293 ** new "v2" interface is recommended for new applications but the legacy
3294 ** interface will continue to be supported.
3296 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
3297 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
3298 ** ^With the "v2" interface, any of the other [result codes] or
3299 ** [extended result codes] might be returned as well.
3301 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
3302 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
3303 ** or occurs outside of an explicit transaction, then you can retry the
3304 ** statement. If the statement is not a [COMMIT] and occurs within an
3305 ** explicit transaction then you should rollback the transaction before
3308 ** ^[SQLITE_DONE] means that the statement has finished executing
3309 ** successfully. sqlite3_step() should not be called again on this virtual
3310 ** machine without first calling [sqlite3_reset()] to reset the virtual
3311 ** machine back to its initial state.
3313 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
3314 ** is returned each time a new row of data is ready for processing by the
3315 ** caller. The values may be accessed using the [column access functions].
3316 ** sqlite3_step() is called again to retrieve the next row of data.
3318 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
3319 ** violation) has occurred. sqlite3_step() should not be called again on
3320 ** the VM. More information may be found by calling [sqlite3_errmsg()].
3321 ** ^With the legacy interface, a more specific error code (for example,
3322 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
3323 ** can be obtained by calling [sqlite3_reset()] on the
3324 ** [prepared statement]. ^In the "v2" interface,
3325 ** the more specific error code is returned directly by sqlite3_step().
3327 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3328 ** Perhaps it was called on a [prepared statement] that has
3329 ** already been [sqlite3_finalize | finalized] or on one that had
3330 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
3331 ** be the case that the same database connection is being used by two or
3332 ** more threads at the same moment in time.
3334 ** For all versions of SQLite up to and including 3.6.23.1, a call to
3335 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
3336 ** other than [SQLITE_ROW] before any subsequent invocation of
3337 ** sqlite3_step(). Failure to reset the prepared statement using
3338 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
3339 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began
3340 ** calling [sqlite3_reset()] automatically in this circumstance rather
3341 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
3342 ** break because any application that ever receives an SQLITE_MISUSE error
3343 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
3344 ** can be used to restore the legacy behavior.
3346 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3347 ** API always returns a generic error code, [SQLITE_ERROR], following any
3348 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
3349 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3350 ** specific [error codes] that better describes the error.
3351 ** We admit that this is a goofy design. The problem has been fixed
3352 ** with the "v2" interface. If you prepare all of your SQL statements
3353 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3354 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3355 ** then the more specific [error codes] are returned directly
3356 ** by sqlite3_step(). The use of the "v2" interface is recommended.
3358 SQLITE_API
int sqlite3_step(sqlite3_stmt
*);
3361 ** CAPI3REF: Number of columns in a result set
3363 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
3364 ** current row of the result set of [prepared statement] P.
3365 ** ^If prepared statement P does not have results ready to return
3366 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
3367 ** interfaces) then sqlite3_data_count(P) returns 0.
3368 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
3369 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
3370 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
3371 ** will return non-zero if previous call to [sqlite3_step](P) returned
3372 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
3373 ** where it always returns zero since each step of that multi-step
3374 ** pragma returns 0 columns of data.
3376 ** See also: [sqlite3_column_count()]
3378 SQLITE_API
int sqlite3_data_count(sqlite3_stmt
*pStmt
);
3381 ** CAPI3REF: Fundamental Datatypes
3382 ** KEYWORDS: SQLITE_TEXT
3384 ** ^(Every value in SQLite has one of five fundamental datatypes:
3387 ** <li> 64-bit signed integer
3388 ** <li> 64-bit IEEE floating point number
3394 ** These constants are codes for each of those types.
3396 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3397 ** for a completely different meaning. Software that links against both
3398 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3401 #define SQLITE_INTEGER 1
3402 #define SQLITE_FLOAT 2
3403 #define SQLITE_BLOB 4
3404 #define SQLITE_NULL 5
3408 # define SQLITE_TEXT 3
3410 #define SQLITE3_TEXT 3
3413 ** CAPI3REF: Result Values From A Query
3414 ** KEYWORDS: {column access functions}
3416 ** These routines form the "result set" interface.
3418 ** ^These routines return information about a single column of the current
3419 ** result row of a query. ^In every case the first argument is a pointer
3420 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3421 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3422 ** and the second argument is the index of the column for which information
3423 ** should be returned. ^The leftmost column of the result set has the index 0.
3424 ** ^The number of columns in the result can be determined using
3425 ** [sqlite3_column_count()].
3427 ** If the SQL statement does not currently point to a valid row, or if the
3428 ** column index is out of range, the result is undefined.
3429 ** These routines may only be called when the most recent call to
3430 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3431 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3432 ** If any of these routines are called after [sqlite3_reset()] or
3433 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3434 ** something other than [SQLITE_ROW], the results are undefined.
3435 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
3436 ** are called from a different thread while any of these routines
3437 ** are pending, then the results are undefined.
3439 ** ^The sqlite3_column_type() routine returns the
3440 ** [SQLITE_INTEGER | datatype code] for the initial data type
3441 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
3442 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
3443 ** returned by sqlite3_column_type() is only meaningful if no type
3444 ** conversions have occurred as described below. After a type conversion,
3445 ** the value returned by sqlite3_column_type() is undefined. Future
3446 ** versions of SQLite may change the behavior of sqlite3_column_type()
3447 ** following a type conversion.
3449 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
3450 ** routine returns the number of bytes in that BLOB or string.
3451 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
3452 ** the string to UTF-8 and then returns the number of bytes.
3453 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
3454 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
3455 ** the number of bytes in that string.
3456 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
3458 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
3459 ** routine returns the number of bytes in that BLOB or string.
3460 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
3461 ** the string to UTF-16 and then returns the number of bytes.
3462 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
3463 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
3464 ** the number of bytes in that string.
3465 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
3467 ** ^The values returned by [sqlite3_column_bytes()] and
3468 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
3469 ** of the string. ^For clarity: the values returned by
3470 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
3471 ** bytes in the string, not the number of characters.
3473 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
3474 ** even empty strings, are always zero terminated. ^The return
3475 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
3477 ** ^The object returned by [sqlite3_column_value()] is an
3478 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
3479 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
3480 ** If the [unprotected sqlite3_value] object returned by
3481 ** [sqlite3_column_value()] is used in any other way, including calls
3482 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
3483 ** or [sqlite3_value_bytes()], then the behavior is undefined.
3485 ** These routines attempt to convert the value where appropriate. ^For
3486 ** example, if the internal representation is FLOAT and a text result
3487 ** is requested, [sqlite3_snprintf()] is used internally to perform the
3488 ** conversion automatically. ^(The following table details the conversions
3489 ** that are applied:
3492 ** <table border="1">
3493 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
3495 ** <tr><td> NULL <td> INTEGER <td> Result is 0
3496 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
3497 ** <tr><td> NULL <td> TEXT <td> Result is NULL pointer
3498 ** <tr><td> NULL <td> BLOB <td> Result is NULL pointer
3499 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
3500 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
3501 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
3502 ** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer
3503 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
3504 ** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT
3505 ** <tr><td> TEXT <td> INTEGER <td> Use atoi()
3506 ** <tr><td> TEXT <td> FLOAT <td> Use atof()
3507 ** <tr><td> TEXT <td> BLOB <td> No change
3508 ** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi()
3509 ** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof()
3510 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
3514 ** The table above makes reference to standard C library functions atoi()
3515 ** and atof(). SQLite does not really use these functions. It has its
3516 ** own equivalent internal routines. The atoi() and atof() names are
3517 ** used in the table for brevity and because they are familiar to most
3520 ** Note that when type conversions occur, pointers returned by prior
3521 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
3522 ** sqlite3_column_text16() may be invalidated.
3523 ** Type conversions and pointer invalidations might occur
3524 ** in the following cases:
3527 ** <li> The initial content is a BLOB and sqlite3_column_text() or
3528 ** sqlite3_column_text16() is called. A zero-terminator might
3529 ** need to be added to the string.</li>
3530 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
3531 ** sqlite3_column_text16() is called. The content must be converted
3533 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
3534 ** sqlite3_column_text() is called. The content must be converted
3538 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
3539 ** not invalidate a prior pointer, though of course the content of the buffer
3540 ** that the prior pointer references will have been modified. Other kinds
3541 ** of conversion are done in place when it is possible, but sometimes they
3542 ** are not possible and in those cases prior pointers are invalidated.
3544 ** The safest and easiest to remember policy is to invoke these routines
3545 ** in one of the following ways:
3548 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
3549 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
3550 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
3553 ** In other words, you should call sqlite3_column_text(),
3554 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
3555 ** into the desired format, then invoke sqlite3_column_bytes() or
3556 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
3557 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
3558 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
3559 ** with calls to sqlite3_column_bytes().
3561 ** ^The pointers returned are valid until a type conversion occurs as
3562 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
3563 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
3564 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned
3565 ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
3566 ** [sqlite3_free()].
3568 ** ^(If a memory allocation error occurs during the evaluation of any
3569 ** of these routines, a default value is returned. The default value
3570 ** is either the integer 0, the floating point number 0.0, or a NULL
3571 ** pointer. Subsequent calls to [sqlite3_errcode()] will return
3572 ** [SQLITE_NOMEM].)^
3574 SQLITE_API
const void *sqlite3_column_blob(sqlite3_stmt
*, int iCol
);
3575 SQLITE_API
int sqlite3_column_bytes(sqlite3_stmt
*, int iCol
);
3576 SQLITE_API
int sqlite3_column_bytes16(sqlite3_stmt
*, int iCol
);
3577 SQLITE_API
double sqlite3_column_double(sqlite3_stmt
*, int iCol
);
3578 SQLITE_API
int sqlite3_column_int(sqlite3_stmt
*, int iCol
);
3579 SQLITE_API sqlite3_int64
sqlite3_column_int64(sqlite3_stmt
*, int iCol
);
3580 SQLITE_API
const unsigned char *sqlite3_column_text(sqlite3_stmt
*, int iCol
);
3581 SQLITE_API
const void *sqlite3_column_text16(sqlite3_stmt
*, int iCol
);
3582 SQLITE_API
int sqlite3_column_type(sqlite3_stmt
*, int iCol
);
3583 SQLITE_API sqlite3_value
*sqlite3_column_value(sqlite3_stmt
*, int iCol
);
3586 ** CAPI3REF: Destroy A Prepared Statement Object
3588 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
3589 ** ^If the most recent evaluation of the statement encountered no errors
3590 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
3591 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
3592 ** sqlite3_finalize(S) returns the appropriate [error code] or
3593 ** [extended error code].
3595 ** ^The sqlite3_finalize(S) routine can be called at any point during
3596 ** the life cycle of [prepared statement] S:
3597 ** before statement S is ever evaluated, after
3598 ** one or more calls to [sqlite3_reset()], or after any call
3599 ** to [sqlite3_step()] regardless of whether or not the statement has
3600 ** completed execution.
3602 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
3604 ** The application must finalize every [prepared statement] in order to avoid
3605 ** resource leaks. It is a grievous error for the application to try to use
3606 ** a prepared statement after it has been finalized. Any use of a prepared
3607 ** statement after it has been finalized can result in undefined and
3608 ** undesirable behavior such as segfaults and heap corruption.
3610 SQLITE_API
int sqlite3_finalize(sqlite3_stmt
*pStmt
);
3613 ** CAPI3REF: Reset A Prepared Statement Object
3615 ** The sqlite3_reset() function is called to reset a [prepared statement]
3616 ** object back to its initial state, ready to be re-executed.
3617 ** ^Any SQL statement variables that had values bound to them using
3618 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
3619 ** Use [sqlite3_clear_bindings()] to reset the bindings.
3621 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
3622 ** back to the beginning of its program.
3624 ** ^If the most recent call to [sqlite3_step(S)] for the
3625 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
3626 ** or if [sqlite3_step(S)] has never before been called on S,
3627 ** then [sqlite3_reset(S)] returns [SQLITE_OK].
3629 ** ^If the most recent call to [sqlite3_step(S)] for the
3630 ** [prepared statement] S indicated an error, then
3631 ** [sqlite3_reset(S)] returns an appropriate [error code].
3633 ** ^The [sqlite3_reset(S)] interface does not change the values
3634 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
3636 SQLITE_API
int sqlite3_reset(sqlite3_stmt
*pStmt
);
3639 ** CAPI3REF: Create Or Redefine SQL Functions
3640 ** KEYWORDS: {function creation routines}
3641 ** KEYWORDS: {application-defined SQL function}
3642 ** KEYWORDS: {application-defined SQL functions}
3644 ** ^These functions (collectively known as "function creation routines")
3645 ** are used to add SQL functions or aggregates or to redefine the behavior
3646 ** of existing SQL functions or aggregates. The only differences between
3647 ** these routines are the text encoding expected for
3648 ** the second parameter (the name of the function being created)
3649 ** and the presence or absence of a destructor callback for
3650 ** the application data pointer.
3652 ** ^The first parameter is the [database connection] to which the SQL
3653 ** function is to be added. ^If an application uses more than one database
3654 ** connection then application-defined SQL functions must be added
3655 ** to each database connection separately.
3657 ** ^The second parameter is the name of the SQL function to be created or
3658 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
3659 ** representation, exclusive of the zero-terminator. ^Note that the name
3660 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
3661 ** ^Any attempt to create a function with a longer name
3662 ** will result in [SQLITE_MISUSE] being returned.
3664 ** ^The third parameter (nArg)
3665 ** is the number of arguments that the SQL function or
3666 ** aggregate takes. ^If this parameter is -1, then the SQL function or
3667 ** aggregate may take any number of arguments between 0 and the limit
3668 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
3669 ** parameter is less than -1 or greater than 127 then the behavior is
3672 ** ^The fourth parameter, eTextRep, specifies what
3673 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
3674 ** its parameters. Every SQL function implementation must be able to work
3675 ** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
3676 ** more efficient with one encoding than another. ^An application may
3677 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
3678 ** times with the same function but with different values of eTextRep.
3679 ** ^When multiple implementations of the same function are available, SQLite
3680 ** will pick the one that involves the least amount of data conversion.
3681 ** If there is only a single implementation which does not care what text
3682 ** encoding is used, then the fourth argument should be [SQLITE_ANY].
3684 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
3685 ** function can gain access to this pointer using [sqlite3_user_data()].)^
3687 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
3688 ** pointers to C-language functions that implement the SQL function or
3689 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
3690 ** callback only; NULL pointers must be passed as the xStep and xFinal
3691 ** parameters. ^An aggregate SQL function requires an implementation of xStep
3692 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
3693 ** SQL function or aggregate, pass NULL pointers for all three function
3696 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
3697 ** then it is destructor for the application data pointer.
3698 ** The destructor is invoked when the function is deleted, either by being
3699 ** overloaded or when the database connection closes.)^
3700 ** ^The destructor is also invoked if the call to
3701 ** sqlite3_create_function_v2() fails.
3702 ** ^When the destructor callback of the tenth parameter is invoked, it
3703 ** is passed a single argument which is a copy of the application data
3704 ** pointer which was the fifth parameter to sqlite3_create_function_v2().
3706 ** ^It is permitted to register multiple implementations of the same
3707 ** functions with the same name but with either differing numbers of
3708 ** arguments or differing preferred text encodings. ^SQLite will use
3709 ** the implementation that most closely matches the way in which the
3710 ** SQL function is used. ^A function implementation with a non-negative
3711 ** nArg parameter is a better match than a function implementation with
3712 ** a negative nArg. ^A function where the preferred text encoding
3713 ** matches the database encoding is a better
3714 ** match than a function where the encoding is different.
3715 ** ^A function where the encoding difference is between UTF16le and UTF16be
3716 ** is a closer match than a function where the encoding difference is
3717 ** between UTF8 and UTF16.
3719 ** ^Built-in functions may be overloaded by new application-defined functions.
3721 ** ^An application-defined function is permitted to call other
3722 ** SQLite interfaces. However, such calls must not
3723 ** close the database connection nor finalize or reset the prepared
3724 ** statement in which the function is running.
3726 SQLITE_API
int sqlite3_create_function(
3728 const char *zFunctionName
,
3732 void (*xFunc
)(sqlite3_context
*,int,sqlite3_value
**),
3733 void (*xStep
)(sqlite3_context
*,int,sqlite3_value
**),
3734 void (*xFinal
)(sqlite3_context
*)
3736 SQLITE_API
int sqlite3_create_function16(
3738 const void *zFunctionName
,
3742 void (*xFunc
)(sqlite3_context
*,int,sqlite3_value
**),
3743 void (*xStep
)(sqlite3_context
*,int,sqlite3_value
**),
3744 void (*xFinal
)(sqlite3_context
*)
3746 SQLITE_API
int sqlite3_create_function_v2(
3748 const char *zFunctionName
,
3752 void (*xFunc
)(sqlite3_context
*,int,sqlite3_value
**),
3753 void (*xStep
)(sqlite3_context
*,int,sqlite3_value
**),
3754 void (*xFinal
)(sqlite3_context
*),
3755 void(*xDestroy
)(void*)
3759 ** CAPI3REF: Text Encodings
3761 ** These constant define integer codes that represent the various
3762 ** text encodings supported by SQLite.
3764 #define SQLITE_UTF8 1
3765 #define SQLITE_UTF16LE 2
3766 #define SQLITE_UTF16BE 3
3767 #define SQLITE_UTF16 4 /* Use native byte order */
3768 #define SQLITE_ANY 5 /* sqlite3_create_function only */
3769 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
3772 ** CAPI3REF: Deprecated Functions
3775 ** These functions are [deprecated]. In order to maintain
3776 ** backwards compatibility with older code, these functions continue
3777 ** to be supported. However, new applications should avoid
3778 ** the use of these functions. To help encourage people to avoid
3779 ** using these functions, we are not going to tell you what they do.
3781 #ifndef SQLITE_OMIT_DEPRECATED
3782 SQLITE_API SQLITE_DEPRECATED
int sqlite3_aggregate_count(sqlite3_context
*);
3783 SQLITE_API SQLITE_DEPRECATED
int sqlite3_expired(sqlite3_stmt
*);
3784 SQLITE_API SQLITE_DEPRECATED
int sqlite3_transfer_bindings(sqlite3_stmt
*, sqlite3_stmt
*);
3785 SQLITE_API SQLITE_DEPRECATED
int sqlite3_global_recover(void);
3786 SQLITE_API SQLITE_DEPRECATED
void sqlite3_thread_cleanup(void);
3787 SQLITE_API SQLITE_DEPRECATED
int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64
,int),void*,sqlite3_int64
);
3791 ** CAPI3REF: Obtaining SQL Function Parameter Values
3793 ** The C-language implementation of SQL functions and aggregates uses
3794 ** this set of interface routines to access the parameter values on
3795 ** the function or aggregate.
3797 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
3798 ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
3799 ** define callbacks that implement the SQL functions and aggregates.
3800 ** The 3rd parameter to these callbacks is an array of pointers to
3801 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
3802 ** each parameter to the SQL function. These routines are used to
3803 ** extract values from the [sqlite3_value] objects.
3805 ** These routines work only with [protected sqlite3_value] objects.
3806 ** Any attempt to use these routines on an [unprotected sqlite3_value]
3807 ** object results in undefined behavior.
3809 ** ^These routines work just like the corresponding [column access functions]
3810 ** except that these routines take a single [protected sqlite3_value] object
3811 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
3813 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
3814 ** in the native byte-order of the host machine. ^The
3815 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
3816 ** extract UTF-16 strings as big-endian and little-endian respectively.
3818 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
3819 ** numeric affinity to the value. This means that an attempt is
3820 ** made to convert the value to an integer or floating point. If
3821 ** such a conversion is possible without loss of information (in other
3822 ** words, if the value is a string that looks like a number)
3823 ** then the conversion is performed. Otherwise no conversion occurs.
3824 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
3826 ** Please pay particular attention to the fact that the pointer returned
3827 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
3828 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
3829 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
3830 ** or [sqlite3_value_text16()].
3832 ** These routines must be called from the same thread as
3833 ** the SQL function that supplied the [sqlite3_value*] parameters.
3835 SQLITE_API
const void *sqlite3_value_blob(sqlite3_value
*);
3836 SQLITE_API
int sqlite3_value_bytes(sqlite3_value
*);
3837 SQLITE_API
int sqlite3_value_bytes16(sqlite3_value
*);
3838 SQLITE_API
double sqlite3_value_double(sqlite3_value
*);
3839 SQLITE_API
int sqlite3_value_int(sqlite3_value
*);
3840 SQLITE_API sqlite3_int64
sqlite3_value_int64(sqlite3_value
*);
3841 SQLITE_API
const unsigned char *sqlite3_value_text(sqlite3_value
*);
3842 SQLITE_API
const void *sqlite3_value_text16(sqlite3_value
*);
3843 SQLITE_API
const void *sqlite3_value_text16le(sqlite3_value
*);
3844 SQLITE_API
const void *sqlite3_value_text16be(sqlite3_value
*);
3845 SQLITE_API
int sqlite3_value_type(sqlite3_value
*);
3846 SQLITE_API
int sqlite3_value_numeric_type(sqlite3_value
*);
3849 ** CAPI3REF: Obtain Aggregate Function Context
3851 ** Implementations of aggregate SQL functions use this
3852 ** routine to allocate memory for storing their state.
3854 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
3855 ** for a particular aggregate function, SQLite
3856 ** allocates N of memory, zeroes out that memory, and returns a pointer
3857 ** to the new memory. ^On second and subsequent calls to
3858 ** sqlite3_aggregate_context() for the same aggregate function instance,
3859 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
3860 ** called once for each invocation of the xStep callback and then one
3861 ** last time when the xFinal callback is invoked. ^(When no rows match
3862 ** an aggregate query, the xStep() callback of the aggregate function
3863 ** implementation is never called and xFinal() is called exactly once.
3864 ** In those cases, sqlite3_aggregate_context() might be called for the
3865 ** first time from within xFinal().)^
3867 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
3868 ** less than or equal to zero or if a memory allocate error occurs.
3870 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
3871 ** determined by the N parameter on first successful call. Changing the
3872 ** value of N in subsequent call to sqlite3_aggregate_context() within
3873 ** the same aggregate function instance will not resize the memory
3876 ** ^SQLite automatically frees the memory allocated by
3877 ** sqlite3_aggregate_context() when the aggregate query concludes.
3879 ** The first parameter must be a copy of the
3880 ** [sqlite3_context | SQL function context] that is the first parameter
3881 ** to the xStep or xFinal callback routine that implements the aggregate
3884 ** This routine must be called from the same thread in which
3885 ** the aggregate SQL function is running.
3887 SQLITE_API
void *sqlite3_aggregate_context(sqlite3_context
*, int nBytes
);
3890 ** CAPI3REF: User Data For Functions
3892 ** ^The sqlite3_user_data() interface returns a copy of
3893 ** the pointer that was the pUserData parameter (the 5th parameter)
3894 ** of the [sqlite3_create_function()]
3895 ** and [sqlite3_create_function16()] routines that originally
3896 ** registered the application defined function.
3898 ** This routine must be called from the same thread in which
3899 ** the application-defined function is running.
3901 SQLITE_API
void *sqlite3_user_data(sqlite3_context
*);
3904 ** CAPI3REF: Database Connection For Functions
3906 ** ^The sqlite3_context_db_handle() interface returns a copy of
3907 ** the pointer to the [database connection] (the 1st parameter)
3908 ** of the [sqlite3_create_function()]
3909 ** and [sqlite3_create_function16()] routines that originally
3910 ** registered the application defined function.
3912 SQLITE_API sqlite3
*sqlite3_context_db_handle(sqlite3_context
*);
3915 ** CAPI3REF: Function Auxiliary Data
3917 ** The following two functions may be used by scalar SQL functions to
3918 ** associate metadata with argument values. If the same value is passed to
3919 ** multiple invocations of the same SQL function during query execution, under
3920 ** some circumstances the associated metadata may be preserved. This may
3921 ** be used, for example, to add a regular-expression matching scalar
3922 ** function. The compiled version of the regular expression is stored as
3923 ** metadata associated with the SQL value passed as the regular expression
3924 ** pattern. The compiled regular expression can be reused on multiple
3925 ** invocations of the same function so that the original pattern string
3926 ** does not need to be recompiled on each invocation.
3928 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
3929 ** associated by the sqlite3_set_auxdata() function with the Nth argument
3930 ** value to the application-defined function. ^If no metadata has been ever
3931 ** been set for the Nth argument of the function, or if the corresponding
3932 ** function parameter has changed since the meta-data was set,
3933 ** then sqlite3_get_auxdata() returns a NULL pointer.
3935 ** ^The sqlite3_set_auxdata() interface saves the metadata
3936 ** pointed to by its 3rd parameter as the metadata for the N-th
3937 ** argument of the application-defined function. Subsequent
3938 ** calls to sqlite3_get_auxdata() might return this data, if it has
3939 ** not been destroyed.
3940 ** ^If it is not NULL, SQLite will invoke the destructor
3941 ** function given by the 4th parameter to sqlite3_set_auxdata() on
3942 ** the metadata when the corresponding function parameter changes
3943 ** or when the SQL statement completes, whichever comes first.
3945 ** SQLite is free to call the destructor and drop metadata on any
3946 ** parameter of any function at any time. ^The only guarantee is that
3947 ** the destructor will be called before the metadata is dropped.
3949 ** ^(In practice, metadata is preserved between function calls for
3950 ** expressions that are constant at compile time. This includes literal
3951 ** values and [parameters].)^
3953 ** These routines must be called from the same thread in which
3954 ** the SQL function is running.
3956 SQLITE_API
void *sqlite3_get_auxdata(sqlite3_context
*, int N
);
3957 SQLITE_API
void sqlite3_set_auxdata(sqlite3_context
*, int N
, void*, void (*)(void*));
3961 ** CAPI3REF: Constants Defining Special Destructor Behavior
3963 ** These are special values for the destructor that is passed in as the
3964 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
3965 ** argument is SQLITE_STATIC, it means that the content pointer is constant
3966 ** and will never change. It does not need to be destroyed. ^The
3967 ** SQLITE_TRANSIENT value means that the content will likely change in
3968 ** the near future and that SQLite should make its own private copy of
3969 ** the content before returning.
3971 ** The typedef is necessary to work around problems in certain
3972 ** C++ compilers. See ticket #2191.
3974 typedef void (*sqlite3_destructor_type
)(void*);
3975 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
3976 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
3979 ** CAPI3REF: Setting The Result Of An SQL Function
3981 ** These routines are used by the xFunc or xFinal callbacks that
3982 ** implement SQL functions and aggregates. See
3983 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
3984 ** for additional information.
3986 ** These functions work very much like the [parameter binding] family of
3987 ** functions used to bind values to host parameters in prepared statements.
3988 ** Refer to the [SQL parameter] documentation for additional information.
3990 ** ^The sqlite3_result_blob() interface sets the result from
3991 ** an application-defined function to be the BLOB whose content is pointed
3992 ** to by the second parameter and which is N bytes long where N is the
3995 ** ^The sqlite3_result_zeroblob() interfaces set the result of
3996 ** the application-defined function to be a BLOB containing all zero
3997 ** bytes and N bytes in size, where N is the value of the 2nd parameter.
3999 ** ^The sqlite3_result_double() interface sets the result from
4000 ** an application-defined function to be a floating point value specified
4001 ** by its 2nd argument.
4003 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4004 ** cause the implemented SQL function to throw an exception.
4005 ** ^SQLite uses the string pointed to by the
4006 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4007 ** as the text of an error message. ^SQLite interprets the error
4008 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
4009 ** interprets the string from sqlite3_result_error16() as UTF-16 in native
4010 ** byte order. ^If the third parameter to sqlite3_result_error()
4011 ** or sqlite3_result_error16() is negative then SQLite takes as the error
4012 ** message all text up through the first zero character.
4013 ** ^If the third parameter to sqlite3_result_error() or
4014 ** sqlite3_result_error16() is non-negative then SQLite takes that many
4015 ** bytes (not characters) from the 2nd parameter as the error message.
4016 ** ^The sqlite3_result_error() and sqlite3_result_error16()
4017 ** routines make a private copy of the error message text before
4018 ** they return. Hence, the calling function can deallocate or
4019 ** modify the text after they return without harm.
4020 ** ^The sqlite3_result_error_code() function changes the error code
4021 ** returned by SQLite as a result of an error in a function. ^By default,
4022 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
4023 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4025 ** ^The sqlite3_result_toobig() interface causes SQLite to throw an error
4026 ** indicating that a string or BLOB is too long to represent.
4028 ** ^The sqlite3_result_nomem() interface causes SQLite to throw an error
4029 ** indicating that a memory allocation failed.
4031 ** ^The sqlite3_result_int() interface sets the return value
4032 ** of the application-defined function to be the 32-bit signed integer
4033 ** value given in the 2nd argument.
4034 ** ^The sqlite3_result_int64() interface sets the return value
4035 ** of the application-defined function to be the 64-bit signed integer
4036 ** value given in the 2nd argument.
4038 ** ^The sqlite3_result_null() interface sets the return value
4039 ** of the application-defined function to be NULL.
4041 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
4042 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4043 ** set the return value of the application-defined function to be
4044 ** a text string which is represented as UTF-8, UTF-16 native byte order,
4045 ** UTF-16 little endian, or UTF-16 big endian, respectively.
4046 ** ^SQLite takes the text result from the application from
4047 ** the 2nd parameter of the sqlite3_result_text* interfaces.
4048 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4049 ** is negative, then SQLite takes result text from the 2nd parameter
4050 ** through the first zero character.
4051 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4052 ** is non-negative, then as many bytes (not characters) of the text
4053 ** pointed to by the 2nd parameter are taken as the application-defined
4054 ** function result. If the 3rd parameter is non-negative, then it
4055 ** must be the byte offset into the string where the NUL terminator would
4056 ** appear if the string where NUL terminated. If any NUL characters occur
4057 ** in the string at a byte offset that is less than the value of the 3rd
4058 ** parameter, then the resulting string will contain embedded NULs and the
4059 ** result of expressions operating on strings with embedded NULs is undefined.
4060 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4061 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4062 ** function as the destructor on the text or BLOB result when it has
4063 ** finished using that result.
4064 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4065 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4066 ** assumes that the text or BLOB result is in constant space and does not
4067 ** copy the content of the parameter nor call a destructor on the content
4068 ** when it has finished using that result.
4069 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4070 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4071 ** then SQLite makes a copy of the result into space obtained from
4072 ** from [sqlite3_malloc()] before it returns.
4074 ** ^The sqlite3_result_value() interface sets the result of
4075 ** the application-defined function to be a copy the
4076 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
4077 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4078 ** so that the [sqlite3_value] specified in the parameter may change or
4079 ** be deallocated after sqlite3_result_value() returns without harm.
4080 ** ^A [protected sqlite3_value] object may always be used where an
4081 ** [unprotected sqlite3_value] object is required, so either
4082 ** kind of [sqlite3_value] object can be used with this interface.
4084 ** If these routines are called from within the different thread
4085 ** than the one containing the application-defined function that received
4086 ** the [sqlite3_context] pointer, the results are undefined.
4088 SQLITE_API
void sqlite3_result_blob(sqlite3_context
*, const void*, int, void(*)(void*));
4089 SQLITE_API
void sqlite3_result_double(sqlite3_context
*, double);
4090 SQLITE_API
void sqlite3_result_error(sqlite3_context
*, const char*, int);
4091 SQLITE_API
void sqlite3_result_error16(sqlite3_context
*, const void*, int);
4092 SQLITE_API
void sqlite3_result_error_toobig(sqlite3_context
*);
4093 SQLITE_API
void sqlite3_result_error_nomem(sqlite3_context
*);
4094 SQLITE_API
void sqlite3_result_error_code(sqlite3_context
*, int);
4095 SQLITE_API
void sqlite3_result_int(sqlite3_context
*, int);
4096 SQLITE_API
void sqlite3_result_int64(sqlite3_context
*, sqlite3_int64
);
4097 SQLITE_API
void sqlite3_result_null(sqlite3_context
*);
4098 SQLITE_API
void sqlite3_result_text(sqlite3_context
*, const char*, int, void(*)(void*));
4099 SQLITE_API
void sqlite3_result_text16(sqlite3_context
*, const void*, int, void(*)(void*));
4100 SQLITE_API
void sqlite3_result_text16le(sqlite3_context
*, const void*, int,void(*)(void*));
4101 SQLITE_API
void sqlite3_result_text16be(sqlite3_context
*, const void*, int,void(*)(void*));
4102 SQLITE_API
void sqlite3_result_value(sqlite3_context
*, sqlite3_value
*);
4103 SQLITE_API
void sqlite3_result_zeroblob(sqlite3_context
*, int n
);
4106 ** CAPI3REF: Define New Collating Sequences
4108 ** ^These functions add, remove, or modify a [collation] associated
4109 ** with the [database connection] specified as the first argument.
4111 ** ^The name of the collation is a UTF-8 string
4112 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4113 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4114 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4115 ** considered to be the same name.
4117 ** ^(The third argument (eTextRep) must be one of the constants:
4119 ** <li> [SQLITE_UTF8],
4120 ** <li> [SQLITE_UTF16LE],
4121 ** <li> [SQLITE_UTF16BE],
4122 ** <li> [SQLITE_UTF16], or
4123 ** <li> [SQLITE_UTF16_ALIGNED].
4125 ** ^The eTextRep argument determines the encoding of strings passed
4126 ** to the collating function callback, xCallback.
4127 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4128 ** force strings to be UTF16 with native byte order.
4129 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4130 ** on an even byte address.
4132 ** ^The fourth argument, pArg, is an application data pointer that is passed
4133 ** through as the first argument to the collating function callback.
4135 ** ^The fifth argument, xCallback, is a pointer to the collating function.
4136 ** ^Multiple collating functions can be registered using the same name but
4137 ** with different eTextRep parameters and SQLite will use whichever
4138 ** function requires the least amount of data transformation.
4139 ** ^If the xCallback argument is NULL then the collating function is
4140 ** deleted. ^When all collating functions having the same name are deleted,
4141 ** that collation is no longer usable.
4143 ** ^The collating function callback is invoked with a copy of the pArg
4144 ** application data pointer and with two strings in the encoding specified
4145 ** by the eTextRep argument. The collating function must return an
4146 ** integer that is negative, zero, or positive
4147 ** if the first string is less than, equal to, or greater than the second,
4148 ** respectively. A collating function must always return the same answer
4149 ** given the same inputs. If two or more collating functions are registered
4150 ** to the same collation name (using different eTextRep values) then all
4151 ** must give an equivalent answer when invoked with equivalent strings.
4152 ** The collating function must obey the following properties for all
4153 ** strings A, B, and C:
4156 ** <li> If A==B then B==A.
4157 ** <li> If A==B and B==C then A==C.
4158 ** <li> If A<B THEN B>A.
4159 ** <li> If A<B and B<C then A<C.
4162 ** If a collating function fails any of the above constraints and that
4163 ** collating function is registered and used, then the behavior of SQLite
4166 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4167 ** with the addition that the xDestroy callback is invoked on pArg when
4168 ** the collating function is deleted.
4169 ** ^Collating functions are deleted when they are overridden by later
4170 ** calls to the collation creation functions or when the
4171 ** [database connection] is closed using [sqlite3_close()].
4173 ** ^The xDestroy callback is <u>not</u> called if the
4174 ** sqlite3_create_collation_v2() function fails. Applications that invoke
4175 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
4176 ** check the return code and dispose of the application data pointer
4177 ** themselves rather than expecting SQLite to deal with it for them.
4178 ** This is different from every other SQLite interface. The inconsistency
4179 ** is unfortunate but cannot be changed without breaking backwards
4182 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4184 SQLITE_API
int sqlite3_create_collation(
4189 int(*xCompare
)(void*,int,const void*,int,const void*)
4191 SQLITE_API
int sqlite3_create_collation_v2(
4196 int(*xCompare
)(void*,int,const void*,int,const void*),
4197 void(*xDestroy
)(void*)
4199 SQLITE_API
int sqlite3_create_collation16(
4204 int(*xCompare
)(void*,int,const void*,int,const void*)
4208 ** CAPI3REF: Collation Needed Callbacks
4210 ** ^To avoid having to register all collation sequences before a database
4211 ** can be used, a single callback function may be registered with the
4212 ** [database connection] to be invoked whenever an undefined collation
4213 ** sequence is required.
4215 ** ^If the function is registered using the sqlite3_collation_needed() API,
4216 ** then it is passed the names of undefined collation sequences as strings
4217 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
4218 ** the names are passed as UTF-16 in machine native byte order.
4219 ** ^A call to either function replaces the existing collation-needed callback.
4221 ** ^(When the callback is invoked, the first argument passed is a copy
4222 ** of the second argument to sqlite3_collation_needed() or
4223 ** sqlite3_collation_needed16(). The second argument is the database
4224 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4225 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4226 ** sequence function required. The fourth parameter is the name of the
4227 ** required collation sequence.)^
4229 ** The callback function should register the desired collation using
4230 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4231 ** [sqlite3_create_collation_v2()].
4233 SQLITE_API
int sqlite3_collation_needed(
4236 void(*)(void*,sqlite3
*,int eTextRep
,const char*)
4238 SQLITE_API
int sqlite3_collation_needed16(
4241 void(*)(void*,sqlite3
*,int eTextRep
,const void*)
4244 #ifdef SQLITE_HAS_CODEC
4246 ** Specify the key for an encrypted database. This routine should be
4247 ** called right after sqlite3_open().
4249 ** The code to implement this API is not available in the public release
4252 SQLITE_API
int sqlite3_key(
4253 sqlite3
*db
, /* Database to be rekeyed */
4254 const void *pKey
, int nKey
/* The key */
4258 ** Change the key on an open database. If the current database is not
4259 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
4260 ** database is decrypted.
4262 ** The code to implement this API is not available in the public release
4265 SQLITE_API
int sqlite3_rekey(
4266 sqlite3
*db
, /* Database to be rekeyed */
4267 const void *pKey
, int nKey
/* The new key */
4271 ** Specify the activation key for a SEE database. Unless
4272 ** activated, none of the SEE routines will work.
4274 SQLITE_API
void sqlite3_activate_see(
4275 const char *zPassPhrase
/* Activation phrase */
4279 #ifdef SQLITE_ENABLE_CEROD
4281 ** Specify the activation key for a CEROD database. Unless
4282 ** activated, none of the CEROD routines will work.
4284 SQLITE_API
void sqlite3_activate_cerod(
4285 const char *zPassPhrase
/* Activation phrase */
4290 ** CAPI3REF: Suspend Execution For A Short Time
4292 ** The sqlite3_sleep() function causes the current thread to suspend execution
4293 ** for at least a number of milliseconds specified in its parameter.
4295 ** If the operating system does not support sleep requests with
4296 ** millisecond time resolution, then the time will be rounded up to
4297 ** the nearest second. The number of milliseconds of sleep actually
4298 ** requested from the operating system is returned.
4300 ** ^SQLite implements this interface by calling the xSleep()
4301 ** method of the default [sqlite3_vfs] object. If the xSleep() method
4302 ** of the default VFS is not implemented correctly, or not implemented at
4303 ** all, then the behavior of sqlite3_sleep() may deviate from the description
4304 ** in the previous paragraphs.
4306 SQLITE_API
int sqlite3_sleep(int);
4309 ** CAPI3REF: Name Of The Folder Holding Temporary Files
4311 ** ^(If this global variable is made to point to a string which is
4312 ** the name of a folder (a.k.a. directory), then all temporary files
4313 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
4314 ** will be placed in that directory.)^ ^If this variable
4315 ** is a NULL pointer, then SQLite performs a search for an appropriate
4316 ** temporary file directory.
4318 ** It is not safe to read or modify this variable in more than one
4319 ** thread at a time. It is not safe to read or modify this variable
4320 ** if a [database connection] is being used at the same time in a separate
4322 ** It is intended that this variable be set once
4323 ** as part of process initialization and before any SQLite interface
4324 ** routines have been called and that this variable remain unchanged
4327 ** ^The [temp_store_directory pragma] may modify this variable and cause
4328 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
4329 ** the [temp_store_directory pragma] always assumes that any string
4330 ** that this variable points to is held in memory obtained from
4331 ** [sqlite3_malloc] and the pragma may attempt to free that memory
4332 ** using [sqlite3_free].
4333 ** Hence, if this variable is modified directly, either it should be
4334 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
4335 ** or else the use of the [temp_store_directory pragma] should be avoided.
4337 SQLITE_API SQLITE_EXTERN
char *sqlite3_temp_directory
;
4340 ** CAPI3REF: Test For Auto-Commit Mode
4341 ** KEYWORDS: {autocommit mode}
4343 ** ^The sqlite3_get_autocommit() interface returns non-zero or
4344 ** zero if the given database connection is or is not in autocommit mode,
4345 ** respectively. ^Autocommit mode is on by default.
4346 ** ^Autocommit mode is disabled by a [BEGIN] statement.
4347 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
4349 ** If certain kinds of errors occur on a statement within a multi-statement
4350 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
4351 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
4352 ** transaction might be rolled back automatically. The only way to
4353 ** find out whether SQLite automatically rolled back the transaction after
4354 ** an error is to use this function.
4356 ** If another thread changes the autocommit status of the database
4357 ** connection while this routine is running, then the return value
4360 SQLITE_API
int sqlite3_get_autocommit(sqlite3
*);
4363 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
4365 ** ^The sqlite3_db_handle interface returns the [database connection] handle
4366 ** to which a [prepared statement] belongs. ^The [database connection]
4367 ** returned by sqlite3_db_handle is the same [database connection]
4368 ** that was the first argument
4369 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
4370 ** create the statement in the first place.
4372 SQLITE_API sqlite3
*sqlite3_db_handle(sqlite3_stmt
*);
4375 ** CAPI3REF: Find the next prepared statement
4377 ** ^This interface returns a pointer to the next [prepared statement] after
4378 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
4379 ** then this interface returns a pointer to the first prepared statement
4380 ** associated with the database connection pDb. ^If no prepared statement
4381 ** satisfies the conditions of this routine, it returns NULL.
4383 ** The [database connection] pointer D in a call to
4384 ** [sqlite3_next_stmt(D,S)] must refer to an open database
4385 ** connection and in particular must not be a NULL pointer.
4387 SQLITE_API sqlite3_stmt
*sqlite3_next_stmt(sqlite3
*pDb
, sqlite3_stmt
*pStmt
);
4390 ** CAPI3REF: Commit And Rollback Notification Callbacks
4392 ** ^The sqlite3_commit_hook() interface registers a callback
4393 ** function to be invoked whenever a transaction is [COMMIT | committed].
4394 ** ^Any callback set by a previous call to sqlite3_commit_hook()
4395 ** for the same database connection is overridden.
4396 ** ^The sqlite3_rollback_hook() interface registers a callback
4397 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
4398 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
4399 ** for the same database connection is overridden.
4400 ** ^The pArg argument is passed through to the callback.
4401 ** ^If the callback on a commit hook function returns non-zero,
4402 ** then the commit is converted into a rollback.
4404 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
4405 ** return the P argument from the previous call of the same function
4406 ** on the same [database connection] D, or NULL for
4407 ** the first call for each function on D.
4409 ** The callback implementation must not do anything that will modify
4410 ** the database connection that invoked the callback. Any actions
4411 ** to modify the database connection must be deferred until after the
4412 ** completion of the [sqlite3_step()] call that triggered the commit
4413 ** or rollback hook in the first place.
4414 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
4415 ** database connections for the meaning of "modify" in this paragraph.
4417 ** ^Registering a NULL function disables the callback.
4419 ** ^When the commit hook callback routine returns zero, the [COMMIT]
4420 ** operation is allowed to continue normally. ^If the commit hook
4421 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
4422 ** ^The rollback hook is invoked on a rollback that results from a commit
4423 ** hook returning non-zero, just as it would be with any other rollback.
4425 ** ^For the purposes of this API, a transaction is said to have been
4426 ** rolled back if an explicit "ROLLBACK" statement is executed, or
4427 ** an error or constraint causes an implicit rollback to occur.
4428 ** ^The rollback callback is not invoked if a transaction is
4429 ** automatically rolled back because the database connection is closed.
4431 ** See also the [sqlite3_update_hook()] interface.
4433 SQLITE_API
void *sqlite3_commit_hook(sqlite3
*, int(*)(void*), void*);
4434 SQLITE_API
void *sqlite3_rollback_hook(sqlite3
*, void(*)(void *), void*);
4437 ** CAPI3REF: Data Change Notification Callbacks
4439 ** ^The sqlite3_update_hook() interface registers a callback function
4440 ** with the [database connection] identified by the first argument
4441 ** to be invoked whenever a row is updated, inserted or deleted.
4442 ** ^Any callback set by a previous call to this function
4443 ** for the same database connection is overridden.
4445 ** ^The second argument is a pointer to the function to invoke when a
4446 ** row is updated, inserted or deleted.
4447 ** ^The first argument to the callback is a copy of the third argument
4448 ** to sqlite3_update_hook().
4449 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
4450 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
4452 ** ^The third and fourth arguments to the callback contain pointers to the
4453 ** database and table name containing the affected row.
4454 ** ^The final callback parameter is the [rowid] of the row.
4455 ** ^In the case of an update, this is the [rowid] after the update takes place.
4457 ** ^(The update hook is not invoked when internal system tables are
4458 ** modified (i.e. sqlite_master and sqlite_sequence).)^
4460 ** ^In the current implementation, the update hook
4461 ** is not invoked when duplication rows are deleted because of an
4462 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
4463 ** invoked when rows are deleted using the [truncate optimization].
4464 ** The exceptions defined in this paragraph might change in a future
4465 ** release of SQLite.
4467 ** The update hook implementation must not do anything that will modify
4468 ** the database connection that invoked the update hook. Any actions
4469 ** to modify the database connection must be deferred until after the
4470 ** completion of the [sqlite3_step()] call that triggered the update hook.
4471 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
4472 ** database connections for the meaning of "modify" in this paragraph.
4474 ** ^The sqlite3_update_hook(D,C,P) function
4475 ** returns the P argument from the previous call
4476 ** on the same [database connection] D, or NULL for
4477 ** the first call on D.
4479 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
4482 SQLITE_API
void *sqlite3_update_hook(
4484 void(*)(void *,int ,char const *,char const *,sqlite3_int64
),
4489 ** CAPI3REF: Enable Or Disable Shared Pager Cache
4490 ** KEYWORDS: {shared cache}
4492 ** ^(This routine enables or disables the sharing of the database cache
4493 ** and schema data structures between [database connection | connections]
4494 ** to the same database. Sharing is enabled if the argument is true
4495 ** and disabled if the argument is false.)^
4497 ** ^Cache sharing is enabled and disabled for an entire process.
4498 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
4499 ** sharing was enabled or disabled for each thread separately.
4501 ** ^(The cache sharing mode set by this interface effects all subsequent
4502 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
4503 ** Existing database connections continue use the sharing mode
4504 ** that was in effect at the time they were opened.)^
4506 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
4507 ** successfully. An [error code] is returned otherwise.)^
4509 ** ^Shared cache is disabled by default. But this might change in
4510 ** future releases of SQLite. Applications that care about shared
4511 ** cache setting should set it explicitly.
4513 ** See Also: [SQLite Shared-Cache Mode]
4515 SQLITE_API
int sqlite3_enable_shared_cache(int);
4518 ** CAPI3REF: Attempt To Free Heap Memory
4520 ** ^The sqlite3_release_memory() interface attempts to free N bytes
4521 ** of heap memory by deallocating non-essential memory allocations
4522 ** held by the database library. Memory used to cache database
4523 ** pages to improve performance is an example of non-essential memory.
4524 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
4525 ** which might be more or less than the amount requested.
4526 ** ^The sqlite3_release_memory() routine is a no-op returning zero
4527 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
4529 SQLITE_API
int sqlite3_release_memory(int);
4532 ** CAPI3REF: Impose A Limit On Heap Size
4534 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
4535 ** soft limit on the amount of heap memory that may be allocated by SQLite.
4536 ** ^SQLite strives to keep heap memory utilization below the soft heap
4537 ** limit by reducing the number of pages held in the page cache
4538 ** as heap memory usages approaches the limit.
4539 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
4540 ** below the limit, it will exceed the limit rather than generate
4541 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
4542 ** is advisory only.
4544 ** ^The return value from sqlite3_soft_heap_limit64() is the size of
4545 ** the soft heap limit prior to the call. ^If the argument N is negative
4546 ** then no change is made to the soft heap limit. Hence, the current
4547 ** size of the soft heap limit can be determined by invoking
4548 ** sqlite3_soft_heap_limit64() with a negative argument.
4550 ** ^If the argument N is zero then the soft heap limit is disabled.
4552 ** ^(The soft heap limit is not enforced in the current implementation
4553 ** if one or more of following conditions are true:
4556 ** <li> The soft heap limit is set to zero.
4557 ** <li> Memory accounting is disabled using a combination of the
4558 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
4559 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
4560 ** <li> An alternative page cache implementation is specified using
4561 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE],...).
4562 ** <li> The page cache allocates from its own memory pool supplied
4563 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
4567 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
4568 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
4569 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
4570 ** the soft heap limit is enforced on every memory allocation. Without
4571 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
4572 ** when memory is allocated by the page cache. Testing suggests that because
4573 ** the page cache is the predominate memory user in SQLite, most
4574 ** applications will achieve adequate soft heap limit enforcement without
4575 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
4577 ** The circumstances under which SQLite will enforce the soft heap limit may
4578 ** changes in future releases of SQLite.
4580 SQLITE_API sqlite3_int64
sqlite3_soft_heap_limit64(sqlite3_int64 N
);
4583 ** CAPI3REF: Deprecated Soft Heap Limit Interface
4586 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
4587 ** interface. This routine is provided for historical compatibility
4588 ** only. All new applications should use the
4589 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
4591 SQLITE_API SQLITE_DEPRECATED
void sqlite3_soft_heap_limit(int N
);
4595 ** CAPI3REF: Extract Metadata About A Column Of A Table
4597 ** ^This routine returns metadata about a specific column of a specific
4598 ** database table accessible using the [database connection] handle
4599 ** passed as the first function argument.
4601 ** ^The column is identified by the second, third and fourth parameters to
4602 ** this function. ^The second parameter is either the name of the database
4603 ** (i.e. "main", "temp", or an attached database) containing the specified
4604 ** table or NULL. ^If it is NULL, then all attached databases are searched
4605 ** for the table using the same algorithm used by the database engine to
4606 ** resolve unqualified table references.
4608 ** ^The third and fourth parameters to this function are the table and column
4609 ** name of the desired column, respectively. Neither of these parameters
4612 ** ^Metadata is returned by writing to the memory locations passed as the 5th
4613 ** and subsequent parameters to this function. ^Any of these arguments may be
4614 ** NULL, in which case the corresponding element of metadata is omitted.
4617 ** <table border="1">
4618 ** <tr><th> Parameter <th> Output<br>Type <th> Description
4620 ** <tr><td> 5th <td> const char* <td> Data type
4621 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
4622 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
4623 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
4624 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
4628 ** ^The memory pointed to by the character pointers returned for the
4629 ** declaration type and collation sequence is valid only until the next
4630 ** call to any SQLite API function.
4632 ** ^If the specified table is actually a view, an [error code] is returned.
4634 ** ^If the specified column is "rowid", "oid" or "_rowid_" and an
4635 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
4636 ** parameters are set for the explicitly declared column. ^(If there is no
4637 ** explicitly declared [INTEGER PRIMARY KEY] column, then the output
4638 ** parameters are set as follows:
4641 ** data type: "INTEGER"
4642 ** collation sequence: "BINARY"
4645 ** auto increment: 0
4648 ** ^(This function may load one or more schemas from database files. If an
4649 ** error occurs during this process, or if the requested table or column
4650 ** cannot be found, an [error code] is returned and an error message left
4651 ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
4653 ** ^This API is only available if the library was compiled with the
4654 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
4656 SQLITE_API
int sqlite3_table_column_metadata(
4657 sqlite3
*db
, /* Connection handle */
4658 const char *zDbName
, /* Database name or NULL */
4659 const char *zTableName
, /* Table name */
4660 const char *zColumnName
, /* Column name */
4661 char const **pzDataType
, /* OUTPUT: Declared data type */
4662 char const **pzCollSeq
, /* OUTPUT: Collation sequence name */
4663 int *pNotNull
, /* OUTPUT: True if NOT NULL constraint exists */
4664 int *pPrimaryKey
, /* OUTPUT: True if column part of PK */
4665 int *pAutoinc
/* OUTPUT: True if column is auto-increment */
4669 ** CAPI3REF: Load An Extension
4671 ** ^This interface loads an SQLite extension library from the named file.
4673 ** ^The sqlite3_load_extension() interface attempts to load an
4674 ** SQLite extension library contained in the file zFile.
4676 ** ^The entry point is zProc.
4677 ** ^zProc may be 0, in which case the name of the entry point
4678 ** defaults to "sqlite3_extension_init".
4679 ** ^The sqlite3_load_extension() interface returns
4680 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
4681 ** ^If an error occurs and pzErrMsg is not 0, then the
4682 ** [sqlite3_load_extension()] interface shall attempt to
4683 ** fill *pzErrMsg with error message text stored in memory
4684 ** obtained from [sqlite3_malloc()]. The calling function
4685 ** should free this memory by calling [sqlite3_free()].
4687 ** ^Extension loading must be enabled using
4688 ** [sqlite3_enable_load_extension()] prior to calling this API,
4689 ** otherwise an error will be returned.
4691 ** See also the [load_extension() SQL function].
4693 SQLITE_API
int sqlite3_load_extension(
4694 sqlite3
*db
, /* Load the extension into this database connection */
4695 const char *zFile
, /* Name of the shared library containing extension */
4696 const char *zProc
, /* Entry point. Derived from zFile if 0 */
4697 char **pzErrMsg
/* Put error message here if not 0 */
4701 ** CAPI3REF: Enable Or Disable Extension Loading
4703 ** ^So as not to open security holes in older applications that are
4704 ** unprepared to deal with extension loading, and as a means of disabling
4705 ** extension loading while evaluating user-entered SQL, the following API
4706 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
4708 ** ^Extension loading is off by default. See ticket #1863.
4709 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
4710 ** to turn extension loading on and call it with onoff==0 to turn
4711 ** it back off again.
4713 SQLITE_API
int sqlite3_enable_load_extension(sqlite3
*db
, int onoff
);
4716 ** CAPI3REF: Automatically Load Statically Linked Extensions
4718 ** ^This interface causes the xEntryPoint() function to be invoked for
4719 ** each new [database connection] that is created. The idea here is that
4720 ** xEntryPoint() is the entry point for a statically linked SQLite extension
4721 ** that is to be automatically loaded into all new database connections.
4723 ** ^(Even though the function prototype shows that xEntryPoint() takes
4724 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
4725 ** arguments and expects and integer result as if the signature of the
4726 ** entry point where as follows:
4728 ** <blockquote><pre>
4729 ** int xEntryPoint(
4730 ** sqlite3 *db,
4731 ** const char **pzErrMsg,
4732 ** const struct sqlite3_api_routines *pThunk
4734 ** </pre></blockquote>)^
4736 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
4737 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
4738 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
4739 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
4740 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
4741 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
4742 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
4744 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
4745 ** on the list of automatic extensions is a harmless no-op. ^No entry point
4746 ** will be called more than once for each database connection that is opened.
4748 ** See also: [sqlite3_reset_auto_extension()].
4750 SQLITE_API
int sqlite3_auto_extension(void (*xEntryPoint
)(void));
4753 ** CAPI3REF: Reset Automatic Extension Loading
4755 ** ^This interface disables all automatic extensions previously
4756 ** registered using [sqlite3_auto_extension()].
4758 SQLITE_API
void sqlite3_reset_auto_extension(void);
4761 ** The interface to the virtual-table mechanism is currently considered
4762 ** to be experimental. The interface might change in incompatible ways.
4763 ** If this is a problem for you, do not use the interface at this time.
4765 ** When the virtual-table mechanism stabilizes, we will declare the
4766 ** interface fixed, support it indefinitely, and remove this comment.
4770 ** Structures used by the virtual table interface
4772 typedef struct sqlite3_vtab sqlite3_vtab
;
4773 typedef struct sqlite3_index_info sqlite3_index_info
;
4774 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor
;
4775 typedef struct sqlite3_module sqlite3_module
;
4778 ** CAPI3REF: Virtual Table Object
4779 ** KEYWORDS: sqlite3_module {virtual table module}
4781 ** This structure, sometimes called a "virtual table module",
4782 ** defines the implementation of a [virtual tables].
4783 ** This structure consists mostly of methods for the module.
4785 ** ^A virtual table module is created by filling in a persistent
4786 ** instance of this structure and passing a pointer to that instance
4787 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
4788 ** ^The registration remains valid until it is replaced by a different
4789 ** module or until the [database connection] closes. The content
4790 ** of this structure must not change while it is registered with
4791 ** any database connection.
4793 struct sqlite3_module
{
4795 int (*xCreate
)(sqlite3
*, void *pAux
,
4796 int argc
, const char *const*argv
,
4797 sqlite3_vtab
**ppVTab
, char**);
4798 int (*xConnect
)(sqlite3
*, void *pAux
,
4799 int argc
, const char *const*argv
,
4800 sqlite3_vtab
**ppVTab
, char**);
4801 int (*xBestIndex
)(sqlite3_vtab
*pVTab
, sqlite3_index_info
*);
4802 int (*xDisconnect
)(sqlite3_vtab
*pVTab
);
4803 int (*xDestroy
)(sqlite3_vtab
*pVTab
);
4804 int (*xOpen
)(sqlite3_vtab
*pVTab
, sqlite3_vtab_cursor
**ppCursor
);
4805 int (*xClose
)(sqlite3_vtab_cursor
*);
4806 int (*xFilter
)(sqlite3_vtab_cursor
*, int idxNum
, const char *idxStr
,
4807 int argc
, sqlite3_value
**argv
);
4808 int (*xNext
)(sqlite3_vtab_cursor
*);
4809 int (*xEof
)(sqlite3_vtab_cursor
*);
4810 int (*xColumn
)(sqlite3_vtab_cursor
*, sqlite3_context
*, int);
4811 int (*xRowid
)(sqlite3_vtab_cursor
*, sqlite3_int64
*pRowid
);
4812 int (*xUpdate
)(sqlite3_vtab
*, int, sqlite3_value
**, sqlite3_int64
*);
4813 int (*xBegin
)(sqlite3_vtab
*pVTab
);
4814 int (*xSync
)(sqlite3_vtab
*pVTab
);
4815 int (*xCommit
)(sqlite3_vtab
*pVTab
);
4816 int (*xRollback
)(sqlite3_vtab
*pVTab
);
4817 int (*xFindFunction
)(sqlite3_vtab
*pVtab
, int nArg
, const char *zName
,
4818 void (**pxFunc
)(sqlite3_context
*,int,sqlite3_value
**),
4820 int (*xRename
)(sqlite3_vtab
*pVtab
, const char *zNew
);
4821 /* The methods above are in version 1 of the sqlite_module object. Those
4822 ** below are for version 2 and greater. */
4823 int (*xSavepoint
)(sqlite3_vtab
*pVTab
, int);
4824 int (*xRelease
)(sqlite3_vtab
*pVTab
, int);
4825 int (*xRollbackTo
)(sqlite3_vtab
*pVTab
, int);
4829 ** CAPI3REF: Virtual Table Indexing Information
4830 ** KEYWORDS: sqlite3_index_info
4832 ** The sqlite3_index_info structure and its substructures is used as part
4833 ** of the [virtual table] interface to
4834 ** pass information into and receive the reply from the [xBestIndex]
4835 ** method of a [virtual table module]. The fields under **Inputs** are the
4836 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
4837 ** results into the **Outputs** fields.
4839 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
4841 ** <blockquote>column OP expr</blockquote>
4843 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
4844 ** stored in aConstraint[].op using one of the
4845 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
4846 ** ^(The index of the column is stored in
4847 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
4848 ** expr on the right-hand side can be evaluated (and thus the constraint
4849 ** is usable) and false if it cannot.)^
4851 ** ^The optimizer automatically inverts terms of the form "expr OP column"
4852 ** and makes other simplifications to the WHERE clause in an attempt to
4853 ** get as many WHERE clause terms into the form shown above as possible.
4854 ** ^The aConstraint[] array only reports WHERE clause terms that are
4855 ** relevant to the particular virtual table being queried.
4857 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
4858 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
4860 ** The [xBestIndex] method must fill aConstraintUsage[] with information
4861 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
4862 ** the right-hand side of the corresponding aConstraint[] is evaluated
4863 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
4864 ** is true, then the constraint is assumed to be fully handled by the
4865 ** virtual table and is not checked again by SQLite.)^
4867 ** ^The idxNum and idxPtr values are recorded and passed into the
4868 ** [xFilter] method.
4869 ** ^[sqlite3_free()] is used to free idxPtr if and only if
4870 ** needToFreeIdxPtr is true.
4872 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
4873 ** the correct order to satisfy the ORDER BY clause so that no separate
4874 ** sorting step is required.
4876 ** ^The estimatedCost value is an estimate of the cost of doing the
4877 ** particular lookup. A full scan of a table with N entries should have
4878 ** a cost of N. A binary search of a table of N entries should have a
4879 ** cost of approximately log(N).
4881 struct sqlite3_index_info
{
4883 int nConstraint
; /* Number of entries in aConstraint */
4884 struct sqlite3_index_constraint
{
4885 int iColumn
; /* Column on left-hand side of constraint */
4886 unsigned char op
; /* Constraint operator */
4887 unsigned char usable
; /* True if this constraint is usable */
4888 int iTermOffset
; /* Used internally - xBestIndex should ignore */
4889 } *aConstraint
; /* Table of WHERE clause constraints */
4890 int nOrderBy
; /* Number of terms in the ORDER BY clause */
4891 struct sqlite3_index_orderby
{
4892 int iColumn
; /* Column number */
4893 unsigned char desc
; /* True for DESC. False for ASC. */
4894 } *aOrderBy
; /* The ORDER BY clause */
4896 struct sqlite3_index_constraint_usage
{
4897 int argvIndex
; /* if >0, constraint is part of argv to xFilter */
4898 unsigned char omit
; /* Do not code a test for this constraint */
4899 } *aConstraintUsage
;
4900 int idxNum
; /* Number used to identify the index */
4901 char *idxStr
; /* String, possibly obtained from sqlite3_malloc */
4902 int needToFreeIdxStr
; /* Free idxStr using sqlite3_free() if true */
4903 int orderByConsumed
; /* True if output is already ordered */
4904 double estimatedCost
; /* Estimated cost of using this index */
4908 ** CAPI3REF: Virtual Table Constraint Operator Codes
4910 ** These macros defined the allowed values for the
4911 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
4912 ** an operator that is part of a constraint term in the wHERE clause of
4913 ** a query that uses a [virtual table].
4915 #define SQLITE_INDEX_CONSTRAINT_EQ 2
4916 #define SQLITE_INDEX_CONSTRAINT_GT 4
4917 #define SQLITE_INDEX_CONSTRAINT_LE 8
4918 #define SQLITE_INDEX_CONSTRAINT_LT 16
4919 #define SQLITE_INDEX_CONSTRAINT_GE 32
4920 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
4923 ** CAPI3REF: Register A Virtual Table Implementation
4925 ** ^These routines are used to register a new [virtual table module] name.
4926 ** ^Module names must be registered before
4927 ** creating a new [virtual table] using the module and before using a
4928 ** preexisting [virtual table] for the module.
4930 ** ^The module name is registered on the [database connection] specified
4931 ** by the first parameter. ^The name of the module is given by the
4932 ** second parameter. ^The third parameter is a pointer to
4933 ** the implementation of the [virtual table module]. ^The fourth
4934 ** parameter is an arbitrary client data pointer that is passed through
4935 ** into the [xCreate] and [xConnect] methods of the virtual table module
4936 ** when a new virtual table is be being created or reinitialized.
4938 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
4939 ** is a pointer to a destructor for the pClientData. ^SQLite will
4940 ** invoke the destructor function (if it is not NULL) when SQLite
4941 ** no longer needs the pClientData pointer. ^The destructor will also
4942 ** be invoked if the call to sqlite3_create_module_v2() fails.
4943 ** ^The sqlite3_create_module()
4944 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
4947 SQLITE_API
int sqlite3_create_module(
4948 sqlite3
*db
, /* SQLite connection to register module with */
4949 const char *zName
, /* Name of the module */
4950 const sqlite3_module
*p
, /* Methods for the module */
4951 void *pClientData
/* Client data for xCreate/xConnect */
4953 SQLITE_API
int sqlite3_create_module_v2(
4954 sqlite3
*db
, /* SQLite connection to register module with */
4955 const char *zName
, /* Name of the module */
4956 const sqlite3_module
*p
, /* Methods for the module */
4957 void *pClientData
, /* Client data for xCreate/xConnect */
4958 void(*xDestroy
)(void*) /* Module destructor function */
4962 ** CAPI3REF: Virtual Table Instance Object
4963 ** KEYWORDS: sqlite3_vtab
4965 ** Every [virtual table module] implementation uses a subclass
4966 ** of this object to describe a particular instance
4967 ** of the [virtual table]. Each subclass will
4968 ** be tailored to the specific needs of the module implementation.
4969 ** The purpose of this superclass is to define certain fields that are
4970 ** common to all module implementations.
4972 ** ^Virtual tables methods can set an error message by assigning a
4973 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
4974 ** take care that any prior string is freed by a call to [sqlite3_free()]
4975 ** prior to assigning a new string to zErrMsg. ^After the error message
4976 ** is delivered up to the client application, the string will be automatically
4977 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
4979 struct sqlite3_vtab
{
4980 const sqlite3_module
*pModule
; /* The module for this virtual table */
4981 int nRef
; /* NO LONGER USED */
4982 char *zErrMsg
; /* Error message from sqlite3_mprintf() */
4983 /* Virtual table implementations will typically add additional fields */
4987 ** CAPI3REF: Virtual Table Cursor Object
4988 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
4990 ** Every [virtual table module] implementation uses a subclass of the
4991 ** following structure to describe cursors that point into the
4992 ** [virtual table] and are used
4993 ** to loop through the virtual table. Cursors are created using the
4994 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
4995 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
4996 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
4997 ** of the module. Each module implementation will define
4998 ** the content of a cursor structure to suit its own needs.
5000 ** This superclass exists in order to define fields of the cursor that
5001 ** are common to all implementations.
5003 struct sqlite3_vtab_cursor
{
5004 sqlite3_vtab
*pVtab
; /* Virtual table of this cursor */
5005 /* Virtual table implementations will typically add additional fields */
5009 ** CAPI3REF: Declare The Schema Of A Virtual Table
5011 ** ^The [xCreate] and [xConnect] methods of a
5012 ** [virtual table module] call this interface
5013 ** to declare the format (the names and datatypes of the columns) of
5014 ** the virtual tables they implement.
5016 SQLITE_API
int sqlite3_declare_vtab(sqlite3
*, const char *zSQL
);
5019 ** CAPI3REF: Overload A Function For A Virtual Table
5021 ** ^(Virtual tables can provide alternative implementations of functions
5022 ** using the [xFindFunction] method of the [virtual table module].
5023 ** But global versions of those functions
5024 ** must exist in order to be overloaded.)^
5026 ** ^(This API makes sure a global version of a function with a particular
5027 ** name and number of parameters exists. If no such function exists
5028 ** before this API is called, a new function is created.)^ ^The implementation
5029 ** of the new function always causes an exception to be thrown. So
5030 ** the new function is not good for anything by itself. Its only
5031 ** purpose is to be a placeholder function that can be overloaded
5032 ** by a [virtual table].
5034 SQLITE_API
int sqlite3_overload_function(sqlite3
*, const char *zFuncName
, int nArg
);
5037 ** The interface to the virtual-table mechanism defined above (back up
5038 ** to a comment remarkably similar to this one) is currently considered
5039 ** to be experimental. The interface might change in incompatible ways.
5040 ** If this is a problem for you, do not use the interface at this time.
5042 ** When the virtual-table mechanism stabilizes, we will declare the
5043 ** interface fixed, support it indefinitely, and remove this comment.
5047 ** CAPI3REF: A Handle To An Open BLOB
5048 ** KEYWORDS: {BLOB handle} {BLOB handles}
5050 ** An instance of this object represents an open BLOB on which
5051 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5052 ** ^Objects of this type are created by [sqlite3_blob_open()]
5053 ** and destroyed by [sqlite3_blob_close()].
5054 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5055 ** can be used to read or write small subsections of the BLOB.
5056 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5058 typedef struct sqlite3_blob sqlite3_blob
;
5061 ** CAPI3REF: Open A BLOB For Incremental I/O
5063 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
5064 ** in row iRow, column zColumn, table zTable in database zDb;
5065 ** in other words, the same BLOB that would be selected by:
5068 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
5071 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
5072 ** and write access. ^If it is zero, the BLOB is opened for read access.
5073 ** ^It is not possible to open a column that is part of an index or primary
5074 ** key for writing. ^If [foreign key constraints] are enabled, it is
5075 ** not possible to open a column that is part of a [child key] for writing.
5077 ** ^Note that the database name is not the filename that contains
5078 ** the database but rather the symbolic name of the database that
5079 ** appears after the AS keyword when the database is connected using [ATTACH].
5080 ** ^For the main database file, the database name is "main".
5081 ** ^For TEMP tables, the database name is "temp".
5083 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
5084 ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
5085 ** to be a null pointer.)^
5086 ** ^This function sets the [database connection] error code and message
5087 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
5088 ** functions. ^Note that the *ppBlob variable is always initialized in a
5089 ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
5090 ** regardless of the success or failure of this routine.
5092 ** ^(If the row that a BLOB handle points to is modified by an
5093 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
5094 ** then the BLOB handle is marked as "expired".
5095 ** This is true if any column of the row is changed, even a column
5096 ** other than the one the BLOB handle is open on.)^
5097 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
5098 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
5099 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
5100 ** rolled back by the expiration of the BLOB. Such changes will eventually
5101 ** commit if the transaction continues to completion.)^
5103 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
5104 ** the opened blob. ^The size of a blob may not be changed by this
5105 ** interface. Use the [UPDATE] SQL command to change the size of a
5108 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
5109 ** and the built-in [zeroblob] SQL function can be used, if desired,
5110 ** to create an empty, zero-filled blob in which to read or write using
5113 ** To avoid a resource leak, every open [BLOB handle] should eventually
5114 ** be released by a call to [sqlite3_blob_close()].
5116 SQLITE_API
int sqlite3_blob_open(
5120 const char *zColumn
,
5123 sqlite3_blob
**ppBlob
5127 ** CAPI3REF: Move a BLOB Handle to a New Row
5129 ** ^This function is used to move an existing blob handle so that it points
5130 ** to a different row of the same database table. ^The new row is identified
5131 ** by the rowid value passed as the second argument. Only the row can be
5132 ** changed. ^The database, table and column on which the blob handle is open
5133 ** remain the same. Moving an existing blob handle to a new row can be
5134 ** faster than closing the existing handle and opening a new one.
5136 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
5137 ** it must exist and there must be either a blob or text value stored in
5138 ** the nominated column.)^ ^If the new row is not present in the table, or if
5139 ** it does not contain a blob or text value, or if another error occurs, an
5140 ** SQLite error code is returned and the blob handle is considered aborted.
5141 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
5142 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
5143 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
5144 ** always returns zero.
5146 ** ^This function sets the database handle error code and message.
5148 SQLITE_API SQLITE_EXPERIMENTAL
int sqlite3_blob_reopen(sqlite3_blob
*, sqlite3_int64
);
5151 ** CAPI3REF: Close A BLOB Handle
5153 ** ^Closes an open [BLOB handle].
5155 ** ^Closing a BLOB shall cause the current transaction to commit
5156 ** if there are no other BLOBs, no pending prepared statements, and the
5157 ** database connection is in [autocommit mode].
5158 ** ^If any writes were made to the BLOB, they might be held in cache
5159 ** until the close operation if they will fit.
5161 ** ^(Closing the BLOB often forces the changes
5162 ** out to disk and so if any I/O errors occur, they will likely occur
5163 ** at the time when the BLOB is closed. Any errors that occur during
5164 ** closing are reported as a non-zero return value.)^
5166 ** ^(The BLOB is closed unconditionally. Even if this routine returns
5167 ** an error code, the BLOB is still closed.)^
5169 ** ^Calling this routine with a null pointer (such as would be returned
5170 ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
5172 SQLITE_API
int sqlite3_blob_close(sqlite3_blob
*);
5175 ** CAPI3REF: Return The Size Of An Open BLOB
5177 ** ^Returns the size in bytes of the BLOB accessible via the
5178 ** successfully opened [BLOB handle] in its only argument. ^The
5179 ** incremental blob I/O routines can only read or overwriting existing
5180 ** blob content; they cannot change the size of a blob.
5182 ** This routine only works on a [BLOB handle] which has been created
5183 ** by a prior successful call to [sqlite3_blob_open()] and which has not
5184 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5185 ** to this routine results in undefined and probably undesirable behavior.
5187 SQLITE_API
int sqlite3_blob_bytes(sqlite3_blob
*);
5190 ** CAPI3REF: Read Data From A BLOB Incrementally
5192 ** ^(This function is used to read data from an open [BLOB handle] into a
5193 ** caller-supplied buffer. N bytes of data are copied into buffer Z
5194 ** from the open BLOB, starting at offset iOffset.)^
5196 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
5197 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
5198 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
5199 ** ^The size of the blob (and hence the maximum value of N+iOffset)
5200 ** can be determined using the [sqlite3_blob_bytes()] interface.
5202 ** ^An attempt to read from an expired [BLOB handle] fails with an
5203 ** error code of [SQLITE_ABORT].
5205 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
5206 ** Otherwise, an [error code] or an [extended error code] is returned.)^
5208 ** This routine only works on a [BLOB handle] which has been created
5209 ** by a prior successful call to [sqlite3_blob_open()] and which has not
5210 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5211 ** to this routine results in undefined and probably undesirable behavior.
5213 ** See also: [sqlite3_blob_write()].
5215 SQLITE_API
int sqlite3_blob_read(sqlite3_blob
*, void *Z
, int N
, int iOffset
);
5218 ** CAPI3REF: Write Data Into A BLOB Incrementally
5220 ** ^This function is used to write data into an open [BLOB handle] from a
5221 ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
5222 ** into the open BLOB, starting at offset iOffset.
5224 ** ^If the [BLOB handle] passed as the first argument was not opened for
5225 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
5226 ** this function returns [SQLITE_READONLY].
5228 ** ^This function may only modify the contents of the BLOB; it is
5229 ** not possible to increase the size of a BLOB using this API.
5230 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
5231 ** [SQLITE_ERROR] is returned and no data is written. ^If N is
5232 ** less than zero [SQLITE_ERROR] is returned and no data is written.
5233 ** The size of the BLOB (and hence the maximum value of N+iOffset)
5234 ** can be determined using the [sqlite3_blob_bytes()] interface.
5236 ** ^An attempt to write to an expired [BLOB handle] fails with an
5237 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
5238 ** before the [BLOB handle] expired are not rolled back by the
5239 ** expiration of the handle, though of course those changes might
5240 ** have been overwritten by the statement that expired the BLOB handle
5241 ** or by other independent statements.
5243 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
5244 ** Otherwise, an [error code] or an [extended error code] is returned.)^
5246 ** This routine only works on a [BLOB handle] which has been created
5247 ** by a prior successful call to [sqlite3_blob_open()] and which has not
5248 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5249 ** to this routine results in undefined and probably undesirable behavior.
5251 ** See also: [sqlite3_blob_read()].
5253 SQLITE_API
int sqlite3_blob_write(sqlite3_blob
*, const void *z
, int n
, int iOffset
);
5256 ** CAPI3REF: Virtual File System Objects
5258 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
5259 ** that SQLite uses to interact
5260 ** with the underlying operating system. Most SQLite builds come with a
5261 ** single default VFS that is appropriate for the host computer.
5262 ** New VFSes can be registered and existing VFSes can be unregistered.
5263 ** The following interfaces are provided.
5265 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
5266 ** ^Names are case sensitive.
5267 ** ^Names are zero-terminated UTF-8 strings.
5268 ** ^If there is no match, a NULL pointer is returned.
5269 ** ^If zVfsName is NULL then the default VFS is returned.
5271 ** ^New VFSes are registered with sqlite3_vfs_register().
5272 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
5273 ** ^The same VFS can be registered multiple times without injury.
5274 ** ^To make an existing VFS into the default VFS, register it again
5275 ** with the makeDflt flag set. If two different VFSes with the
5276 ** same name are registered, the behavior is undefined. If a
5277 ** VFS is registered with a name that is NULL or an empty string,
5278 ** then the behavior is undefined.
5280 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
5281 ** ^(If the default VFS is unregistered, another VFS is chosen as
5282 ** the default. The choice for the new VFS is arbitrary.)^
5284 SQLITE_API sqlite3_vfs
*sqlite3_vfs_find(const char *zVfsName
);
5285 SQLITE_API
int sqlite3_vfs_register(sqlite3_vfs
*, int makeDflt
);
5286 SQLITE_API
int sqlite3_vfs_unregister(sqlite3_vfs
*);
5289 ** CAPI3REF: Mutexes
5291 ** The SQLite core uses these routines for thread
5292 ** synchronization. Though they are intended for internal
5293 ** use by SQLite, code that links against SQLite is
5294 ** permitted to use any of these routines.
5296 ** The SQLite source code contains multiple implementations
5297 ** of these mutex routines. An appropriate implementation
5298 ** is selected automatically at compile-time. ^(The following
5299 ** implementations are available in the SQLite core:
5302 ** <li> SQLITE_MUTEX_OS2
5303 ** <li> SQLITE_MUTEX_PTHREAD
5304 ** <li> SQLITE_MUTEX_W32
5305 ** <li> SQLITE_MUTEX_NOOP
5308 ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
5309 ** that does no real locking and is appropriate for use in
5310 ** a single-threaded application. ^The SQLITE_MUTEX_OS2,
5311 ** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
5312 ** are appropriate for use on OS/2, Unix, and Windows.
5314 ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
5315 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
5316 ** implementation is included with the library. In this case the
5317 ** application must supply a custom mutex implementation using the
5318 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
5319 ** before calling sqlite3_initialize() or any other public sqlite3_
5320 ** function that calls sqlite3_initialize().)^
5322 ** ^The sqlite3_mutex_alloc() routine allocates a new
5323 ** mutex and returns a pointer to it. ^If it returns NULL
5324 ** that means that a mutex could not be allocated. ^SQLite
5325 ** will unwind its stack and return an error. ^(The argument
5326 ** to sqlite3_mutex_alloc() is one of these integer constants:
5329 ** <li> SQLITE_MUTEX_FAST
5330 ** <li> SQLITE_MUTEX_RECURSIVE
5331 ** <li> SQLITE_MUTEX_STATIC_MASTER
5332 ** <li> SQLITE_MUTEX_STATIC_MEM
5333 ** <li> SQLITE_MUTEX_STATIC_MEM2
5334 ** <li> SQLITE_MUTEX_STATIC_PRNG
5335 ** <li> SQLITE_MUTEX_STATIC_LRU
5336 ** <li> SQLITE_MUTEX_STATIC_LRU2
5339 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
5340 ** cause sqlite3_mutex_alloc() to create
5341 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
5342 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
5343 ** The mutex implementation does not need to make a distinction
5344 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
5345 ** not want to. ^SQLite will only request a recursive mutex in
5346 ** cases where it really needs one. ^If a faster non-recursive mutex
5347 ** implementation is available on the host platform, the mutex subsystem
5348 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
5350 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
5351 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
5352 ** a pointer to a static preexisting mutex. ^Six static mutexes are
5353 ** used by the current version of SQLite. Future versions of SQLite
5354 ** may add additional static mutexes. Static mutexes are for internal
5355 ** use by SQLite only. Applications that use SQLite mutexes should
5356 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
5357 ** SQLITE_MUTEX_RECURSIVE.
5359 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
5360 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
5361 ** returns a different mutex on every call. ^But for the static
5362 ** mutex types, the same mutex is returned on every call that has
5363 ** the same type number.
5365 ** ^The sqlite3_mutex_free() routine deallocates a previously
5366 ** allocated dynamic mutex. ^SQLite is careful to deallocate every
5367 ** dynamic mutex that it allocates. The dynamic mutexes must not be in
5368 ** use when they are deallocated. Attempting to deallocate a static
5369 ** mutex results in undefined behavior. ^SQLite never deallocates
5372 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
5373 ** to enter a mutex. ^If another thread is already within the mutex,
5374 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
5375 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
5376 ** upon successful entry. ^(Mutexes created using
5377 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
5378 ** In such cases the,
5379 ** mutex must be exited an equal number of times before another thread
5380 ** can enter.)^ ^(If the same thread tries to enter any other
5381 ** kind of mutex more than once, the behavior is undefined.
5382 ** SQLite will never exhibit
5383 ** such behavior in its own use of mutexes.)^
5385 ** ^(Some systems (for example, Windows 95) do not support the operation
5386 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
5387 ** will always return SQLITE_BUSY. The SQLite core only ever uses
5388 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
5390 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
5391 ** previously entered by the same thread. ^(The behavior
5392 ** is undefined if the mutex is not currently entered by the
5393 ** calling thread or is not currently allocated. SQLite will
5394 ** never do either.)^
5396 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
5397 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
5398 ** behave as no-ops.
5400 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
5402 SQLITE_API sqlite3_mutex
*sqlite3_mutex_alloc(int);
5403 SQLITE_API
void sqlite3_mutex_free(sqlite3_mutex
*);
5404 SQLITE_API
void sqlite3_mutex_enter(sqlite3_mutex
*);
5405 SQLITE_API
int sqlite3_mutex_try(sqlite3_mutex
*);
5406 SQLITE_API
void sqlite3_mutex_leave(sqlite3_mutex
*);
5409 ** CAPI3REF: Mutex Methods Object
5411 ** An instance of this structure defines the low-level routines
5412 ** used to allocate and use mutexes.
5414 ** Usually, the default mutex implementations provided by SQLite are
5415 ** sufficient, however the user has the option of substituting a custom
5416 ** implementation for specialized deployments or systems for which SQLite
5417 ** does not provide a suitable implementation. In this case, the user
5418 ** creates and populates an instance of this structure to pass
5419 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
5420 ** Additionally, an instance of this structure can be used as an
5421 ** output variable when querying the system for the current mutex
5422 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
5424 ** ^The xMutexInit method defined by this structure is invoked as
5425 ** part of system initialization by the sqlite3_initialize() function.
5426 ** ^The xMutexInit routine is called by SQLite exactly once for each
5427 ** effective call to [sqlite3_initialize()].
5429 ** ^The xMutexEnd method defined by this structure is invoked as
5430 ** part of system shutdown by the sqlite3_shutdown() function. The
5431 ** implementation of this method is expected to release all outstanding
5432 ** resources obtained by the mutex methods implementation, especially
5433 ** those obtained by the xMutexInit method. ^The xMutexEnd()
5434 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
5436 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
5437 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
5438 ** xMutexNotheld) implement the following interfaces (respectively):
5441 ** <li> [sqlite3_mutex_alloc()] </li>
5442 ** <li> [sqlite3_mutex_free()] </li>
5443 ** <li> [sqlite3_mutex_enter()] </li>
5444 ** <li> [sqlite3_mutex_try()] </li>
5445 ** <li> [sqlite3_mutex_leave()] </li>
5446 ** <li> [sqlite3_mutex_held()] </li>
5447 ** <li> [sqlite3_mutex_notheld()] </li>
5450 ** The only difference is that the public sqlite3_XXX functions enumerated
5451 ** above silently ignore any invocations that pass a NULL pointer instead
5452 ** of a valid mutex handle. The implementations of the methods defined
5453 ** by this structure are not required to handle this case, the results
5454 ** of passing a NULL pointer instead of a valid mutex handle are undefined
5455 ** (i.e. it is acceptable to provide an implementation that segfaults if
5456 ** it is passed a NULL pointer).
5458 ** The xMutexInit() method must be threadsafe. ^It must be harmless to
5459 ** invoke xMutexInit() multiple times within the same process and without
5460 ** intervening calls to xMutexEnd(). Second and subsequent calls to
5461 ** xMutexInit() must be no-ops.
5463 ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
5464 ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory
5465 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
5466 ** memory allocation for a fast or recursive mutex.
5468 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
5469 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
5470 ** If xMutexInit fails in any way, it is expected to clean up after itself
5471 ** prior to returning.
5473 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods
;
5474 struct sqlite3_mutex_methods
{
5475 int (*xMutexInit
)(void);
5476 int (*xMutexEnd
)(void);
5477 sqlite3_mutex
*(*xMutexAlloc
)(int);
5478 void (*xMutexFree
)(sqlite3_mutex
*);
5479 void (*xMutexEnter
)(sqlite3_mutex
*);
5480 int (*xMutexTry
)(sqlite3_mutex
*);
5481 void (*xMutexLeave
)(sqlite3_mutex
*);
5482 int (*xMutexHeld
)(sqlite3_mutex
*);
5483 int (*xMutexNotheld
)(sqlite3_mutex
*);
5487 ** CAPI3REF: Mutex Verification Routines
5489 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
5490 ** are intended for use inside assert() statements. ^The SQLite core
5491 ** never uses these routines except inside an assert() and applications
5492 ** are advised to follow the lead of the core. ^The SQLite core only
5493 ** provides implementations for these routines when it is compiled
5494 ** with the SQLITE_DEBUG flag. ^External mutex implementations
5495 ** are only required to provide these routines if SQLITE_DEBUG is
5496 ** defined and if NDEBUG is not defined.
5498 ** ^These routines should return true if the mutex in their argument
5499 ** is held or not held, respectively, by the calling thread.
5501 ** ^The implementation is not required to provided versions of these
5502 ** routines that actually work. If the implementation does not provide working
5503 ** versions of these routines, it should at least provide stubs that always
5504 ** return true so that one does not get spurious assertion failures.
5506 ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
5507 ** the routine should return 1. This seems counter-intuitive since
5508 ** clearly the mutex cannot be held if it does not exist. But
5509 ** the reason the mutex does not exist is because the build is not
5510 ** using mutexes. And we do not want the assert() containing the
5511 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
5512 ** the appropriate thing to do. ^The sqlite3_mutex_notheld()
5513 ** interface should also return 1 when given a NULL pointer.
5516 SQLITE_API
int sqlite3_mutex_held(sqlite3_mutex
*);
5517 SQLITE_API
int sqlite3_mutex_notheld(sqlite3_mutex
*);
5521 ** CAPI3REF: Mutex Types
5523 ** The [sqlite3_mutex_alloc()] interface takes a single argument
5524 ** which is one of these integer constants.
5526 ** The set of static mutexes may change from one SQLite release to the
5527 ** next. Applications that override the built-in mutex logic must be
5528 ** prepared to accommodate additional static mutexes.
5530 #define SQLITE_MUTEX_FAST 0
5531 #define SQLITE_MUTEX_RECURSIVE 1
5532 #define SQLITE_MUTEX_STATIC_MASTER 2
5533 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
5534 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
5535 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
5536 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */
5537 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
5538 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
5539 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
5542 ** CAPI3REF: Retrieve the mutex for a database connection
5544 ** ^This interface returns a pointer the [sqlite3_mutex] object that
5545 ** serializes access to the [database connection] given in the argument
5546 ** when the [threading mode] is Serialized.
5547 ** ^If the [threading mode] is Single-thread or Multi-thread then this
5548 ** routine returns a NULL pointer.
5550 SQLITE_API sqlite3_mutex
*sqlite3_db_mutex(sqlite3
*);
5553 ** CAPI3REF: Low-Level Control Of Database Files
5555 ** ^The [sqlite3_file_control()] interface makes a direct call to the
5556 ** xFileControl method for the [sqlite3_io_methods] object associated
5557 ** with a particular database identified by the second argument. ^The
5558 ** name of the database is "main" for the main database or "temp" for the
5559 ** TEMP database, or the name that appears after the AS keyword for
5560 ** databases that are added using the [ATTACH] SQL command.
5561 ** ^A NULL pointer can be used in place of "main" to refer to the
5562 ** main database file.
5563 ** ^The third and fourth parameters to this routine
5564 ** are passed directly through to the second and third parameters of
5565 ** the xFileControl method. ^The return value of the xFileControl
5566 ** method becomes the return value of this routine.
5568 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
5569 ** a pointer to the underlying [sqlite3_file] object to be written into
5570 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
5571 ** case is a short-circuit path which does not actually invoke the
5572 ** underlying sqlite3_io_methods.xFileControl method.
5574 ** ^If the second parameter (zDbName) does not match the name of any
5575 ** open database file, then SQLITE_ERROR is returned. ^This error
5576 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
5577 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
5578 ** also return SQLITE_ERROR. There is no way to distinguish between
5579 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
5580 ** xFileControl method.
5582 ** See also: [SQLITE_FCNTL_LOCKSTATE]
5584 SQLITE_API
int sqlite3_file_control(sqlite3
*, const char *zDbName
, int op
, void*);
5587 ** CAPI3REF: Testing Interface
5589 ** ^The sqlite3_test_control() interface is used to read out internal
5590 ** state of SQLite and to inject faults into SQLite for testing
5591 ** purposes. ^The first parameter is an operation code that determines
5592 ** the number, meaning, and operation of all subsequent parameters.
5594 ** This interface is not for use by applications. It exists solely
5595 ** for verifying the correct operation of the SQLite library. Depending
5596 ** on how the SQLite library is compiled, this interface might not exist.
5598 ** The details of the operation codes, their meanings, the parameters
5599 ** they take, and what they do are all subject to change without notice.
5600 ** Unlike most of the SQLite API, this function is not guaranteed to
5601 ** operate consistently from one release to the next.
5603 SQLITE_API
int sqlite3_test_control(int op
, ...);
5606 ** CAPI3REF: Testing Interface Operation Codes
5608 ** These constants are the valid operation code parameters used
5609 ** as the first argument to [sqlite3_test_control()].
5611 ** These parameters and their meanings are subject to change
5612 ** without notice. These values are for testing purposes only.
5613 ** Applications should not use any of these parameters or the
5614 ** [sqlite3_test_control()] interface.
5616 #define SQLITE_TESTCTRL_FIRST 5
5617 #define SQLITE_TESTCTRL_PRNG_SAVE 5
5618 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
5619 #define SQLITE_TESTCTRL_PRNG_RESET 7
5620 #define SQLITE_TESTCTRL_BITVEC_TEST 8
5621 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
5622 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
5623 #define SQLITE_TESTCTRL_PENDING_BYTE 11
5624 #define SQLITE_TESTCTRL_ASSERT 12
5625 #define SQLITE_TESTCTRL_ALWAYS 13
5626 #define SQLITE_TESTCTRL_RESERVE 14
5627 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
5628 #define SQLITE_TESTCTRL_ISKEYWORD 16
5629 #define SQLITE_TESTCTRL_PGHDRSZ 17
5630 #define SQLITE_TESTCTRL_SCRATCHMALLOC 18
5631 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 19
5632 #define SQLITE_TESTCTRL_LAST 19
5635 ** CAPI3REF: SQLite Runtime Status
5637 ** ^This interface is used to retrieve runtime status information
5638 ** about the performance of SQLite, and optionally to reset various
5639 ** highwater marks. ^The first argument is an integer code for
5640 ** the specific parameter to measure. ^(Recognized integer codes
5641 ** are of the form [status parameters | SQLITE_STATUS_...].)^
5642 ** ^The current value of the parameter is returned into *pCurrent.
5643 ** ^The highest recorded value is returned in *pHighwater. ^If the
5644 ** resetFlag is true, then the highest record value is reset after
5645 ** *pHighwater is written. ^(Some parameters do not record the highest
5646 ** value. For those parameters
5647 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
5648 ** ^(Other parameters record only the highwater mark and not the current
5649 ** value. For these latter parameters nothing is written into *pCurrent.)^
5651 ** ^The sqlite3_status() routine returns SQLITE_OK on success and a
5652 ** non-zero [error code] on failure.
5654 ** This routine is threadsafe but is not atomic. This routine can be
5655 ** called while other threads are running the same or different SQLite
5656 ** interfaces. However the values returned in *pCurrent and
5657 ** *pHighwater reflect the status of SQLite at different points in time
5658 ** and it is possible that another thread might change the parameter
5659 ** in between the times when *pCurrent and *pHighwater are written.
5661 ** See also: [sqlite3_db_status()]
5663 SQLITE_API
int sqlite3_status(int op
, int *pCurrent
, int *pHighwater
, int resetFlag
);
5667 ** CAPI3REF: Status Parameters
5668 ** KEYWORDS: {status parameters}
5670 ** These integer constants designate various run-time status parameters
5671 ** that can be returned by [sqlite3_status()].
5674 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
5675 ** <dd>This parameter is the current amount of memory checked out
5676 ** using [sqlite3_malloc()], either directly or indirectly. The
5677 ** figure includes calls made to [sqlite3_malloc()] by the application
5678 ** and internal memory usage by the SQLite library. Scratch memory
5679 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
5680 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
5681 ** this parameter. The amount returned is the sum of the allocation
5682 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
5684 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
5685 ** <dd>This parameter records the largest memory allocation request
5686 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
5687 ** internal equivalents). Only the value returned in the
5688 ** *pHighwater parameter to [sqlite3_status()] is of interest.
5689 ** The value written into the *pCurrent parameter is undefined.</dd>)^
5691 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
5692 ** <dd>This parameter records the number of separate memory allocations
5693 ** currently checked out.</dd>)^
5695 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
5696 ** <dd>This parameter returns the number of pages used out of the
5697 ** [pagecache memory allocator] that was configured using
5698 ** [SQLITE_CONFIG_PAGECACHE]. The
5699 ** value returned is in pages, not in bytes.</dd>)^
5701 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
5702 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
5703 ** <dd>This parameter returns the number of bytes of page cache
5704 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
5705 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
5706 ** returned value includes allocations that overflowed because they
5707 ** where too large (they were larger than the "sz" parameter to
5708 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
5709 ** no space was left in the page cache.</dd>)^
5711 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
5712 ** <dd>This parameter records the largest memory allocation request
5713 ** handed to [pagecache memory allocator]. Only the value returned in the
5714 ** *pHighwater parameter to [sqlite3_status()] is of interest.
5715 ** The value written into the *pCurrent parameter is undefined.</dd>)^
5717 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
5718 ** <dd>This parameter returns the number of allocations used out of the
5719 ** [scratch memory allocator] configured using
5720 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
5721 ** in bytes. Since a single thread may only have one scratch allocation
5722 ** outstanding at time, this parameter also reports the number of threads
5723 ** using scratch memory at the same time.</dd>)^
5725 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
5726 ** <dd>This parameter returns the number of bytes of scratch memory
5727 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
5728 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values
5729 ** returned include overflows because the requested allocation was too
5730 ** larger (that is, because the requested allocation was larger than the
5731 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
5732 ** slots were available.
5735 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
5736 ** <dd>This parameter records the largest memory allocation request
5737 ** handed to [scratch memory allocator]. Only the value returned in the
5738 ** *pHighwater parameter to [sqlite3_status()] is of interest.
5739 ** The value written into the *pCurrent parameter is undefined.</dd>)^
5741 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
5742 ** <dd>This parameter records the deepest parser stack. It is only
5743 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
5746 ** New status parameters may be added from time to time.
5748 #define SQLITE_STATUS_MEMORY_USED 0
5749 #define SQLITE_STATUS_PAGECACHE_USED 1
5750 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
5751 #define SQLITE_STATUS_SCRATCH_USED 3
5752 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4
5753 #define SQLITE_STATUS_MALLOC_SIZE 5
5754 #define SQLITE_STATUS_PARSER_STACK 6
5755 #define SQLITE_STATUS_PAGECACHE_SIZE 7
5756 #define SQLITE_STATUS_SCRATCH_SIZE 8
5757 #define SQLITE_STATUS_MALLOC_COUNT 9
5760 ** CAPI3REF: Database Connection Status
5762 ** ^This interface is used to retrieve runtime status information
5763 ** about a single [database connection]. ^The first argument is the
5764 ** database connection object to be interrogated. ^The second argument
5765 ** is an integer constant, taken from the set of
5766 ** [SQLITE_DBSTATUS options], that
5767 ** determines the parameter to interrogate. The set of
5768 ** [SQLITE_DBSTATUS options] is likely
5769 ** to grow in future releases of SQLite.
5771 ** ^The current value of the requested parameter is written into *pCur
5772 ** and the highest instantaneous value is written into *pHiwtr. ^If
5773 ** the resetFlg is true, then the highest instantaneous value is
5774 ** reset back down to the current value.
5776 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
5777 ** non-zero [error code] on failure.
5779 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
5781 SQLITE_API
int sqlite3_db_status(sqlite3
*, int op
, int *pCur
, int *pHiwtr
, int resetFlg
);
5784 ** CAPI3REF: Status Parameters for database connections
5785 ** KEYWORDS: {SQLITE_DBSTATUS options}
5787 ** These constants are the available integer "verbs" that can be passed as
5788 ** the second argument to the [sqlite3_db_status()] interface.
5790 ** New verbs may be added in future releases of SQLite. Existing verbs
5791 ** might be discontinued. Applications should check the return code from
5792 ** [sqlite3_db_status()] to make sure that the call worked.
5793 ** The [sqlite3_db_status()] interface will return a non-zero error code
5794 ** if a discontinued or unsupported verb is invoked.
5797 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
5798 ** <dd>This parameter returns the number of lookaside memory slots currently
5799 ** checked out.</dd>)^
5801 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
5802 ** <dd>This parameter returns the number malloc attempts that were
5803 ** satisfied using lookaside memory. Only the high-water value is meaningful;
5804 ** the current value is always zero.)^
5806 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
5807 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
5808 ** <dd>This parameter returns the number malloc attempts that might have
5809 ** been satisfied using lookaside memory but failed due to the amount of
5810 ** memory requested being larger than the lookaside slot size.
5811 ** Only the high-water value is meaningful;
5812 ** the current value is always zero.)^
5814 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
5815 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
5816 ** <dd>This parameter returns the number malloc attempts that might have
5817 ** been satisfied using lookaside memory but failed due to all lookaside
5818 ** memory already being in use.
5819 ** Only the high-water value is meaningful;
5820 ** the current value is always zero.)^
5822 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
5823 ** <dd>This parameter returns the approximate number of of bytes of heap
5824 ** memory used by all pager caches associated with the database connection.)^
5825 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
5827 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
5828 ** <dd>This parameter returns the approximate number of of bytes of heap
5829 ** memory used to store the schema for all databases associated
5830 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
5831 ** ^The full amount of memory used by the schemas is reported, even if the
5832 ** schema memory is shared with other database connections due to
5833 ** [shared cache mode] being enabled.
5834 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
5836 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
5837 ** <dd>This parameter returns the approximate number of of bytes of heap
5838 ** and lookaside memory used by all prepared statements associated with
5839 ** the database connection.)^
5840 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
5843 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
5844 ** <dd>This parameter returns the number of pager cache hits that have
5845 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
5849 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
5850 ** <dd>This parameter returns the number of pager cache misses that have
5851 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
5856 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
5857 #define SQLITE_DBSTATUS_CACHE_USED 1
5858 #define SQLITE_DBSTATUS_SCHEMA_USED 2
5859 #define SQLITE_DBSTATUS_STMT_USED 3
5860 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
5861 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
5862 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
5863 #define SQLITE_DBSTATUS_CACHE_HIT 7
5864 #define SQLITE_DBSTATUS_CACHE_MISS 8
5865 #define SQLITE_DBSTATUS_MAX 8 /* Largest defined DBSTATUS */
5869 ** CAPI3REF: Prepared Statement Status
5871 ** ^(Each prepared statement maintains various
5872 ** [SQLITE_STMTSTATUS counters] that measure the number
5873 ** of times it has performed specific operations.)^ These counters can
5874 ** be used to monitor the performance characteristics of the prepared
5875 ** statements. For example, if the number of table steps greatly exceeds
5876 ** the number of table searches or result rows, that would tend to indicate
5877 ** that the prepared statement is using a full table scan rather than
5880 ** ^(This interface is used to retrieve and reset counter values from
5881 ** a [prepared statement]. The first argument is the prepared statement
5882 ** object to be interrogated. The second argument
5883 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
5884 ** to be interrogated.)^
5885 ** ^The current value of the requested counter is returned.
5886 ** ^If the resetFlg is true, then the counter is reset to zero after this
5887 ** interface call returns.
5889 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
5891 SQLITE_API
int sqlite3_stmt_status(sqlite3_stmt
*, int op
,int resetFlg
);
5894 ** CAPI3REF: Status Parameters for prepared statements
5895 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
5897 ** These preprocessor macros define integer codes that name counter
5898 ** values associated with the [sqlite3_stmt_status()] interface.
5899 ** The meanings of the various counters are as follows:
5902 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
5903 ** <dd>^This is the number of times that SQLite has stepped forward in
5904 ** a table as part of a full table scan. Large numbers for this counter
5905 ** may indicate opportunities for performance improvement through
5906 ** careful use of indices.</dd>
5908 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
5909 ** <dd>^This is the number of sort operations that have occurred.
5910 ** A non-zero value in this counter may indicate an opportunity to
5911 ** improvement performance through careful use of indices.</dd>
5913 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
5914 ** <dd>^This is the number of rows inserted into transient indices that
5915 ** were created automatically in order to help joins run faster.
5916 ** A non-zero value in this counter may indicate an opportunity to
5917 ** improvement performance by adding permanent indices that do not
5918 ** need to be reinitialized each time the statement is run.</dd>
5921 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
5922 #define SQLITE_STMTSTATUS_SORT 2
5923 #define SQLITE_STMTSTATUS_AUTOINDEX 3
5926 ** CAPI3REF: Custom Page Cache Object
5928 ** The sqlite3_pcache type is opaque. It is implemented by
5929 ** the pluggable module. The SQLite core has no knowledge of
5930 ** its size or internal structure and never deals with the
5931 ** sqlite3_pcache object except by holding and passing pointers
5934 ** See [sqlite3_pcache_methods] for additional information.
5936 typedef struct sqlite3_pcache sqlite3_pcache
;
5939 ** CAPI3REF: Application Defined Page Cache.
5940 ** KEYWORDS: {page cache}
5942 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can
5943 ** register an alternative page cache implementation by passing in an
5944 ** instance of the sqlite3_pcache_methods structure.)^
5945 ** In many applications, most of the heap memory allocated by
5946 ** SQLite is used for the page cache.
5947 ** By implementing a
5948 ** custom page cache using this API, an application can better control
5949 ** the amount of memory consumed by SQLite, the way in which
5950 ** that memory is allocated and released, and the policies used to
5951 ** determine exactly which parts of a database file are cached and for
5954 ** The alternative page cache mechanism is an
5955 ** extreme measure that is only needed by the most demanding applications.
5956 ** The built-in page cache is recommended for most uses.
5958 ** ^(The contents of the sqlite3_pcache_methods structure are copied to an
5959 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
5960 ** the application may discard the parameter after the call to
5961 ** [sqlite3_config()] returns.)^
5963 ** [[the xInit() page cache method]]
5964 ** ^(The xInit() method is called once for each effective
5965 ** call to [sqlite3_initialize()])^
5966 ** (usually only once during the lifetime of the process). ^(The xInit()
5967 ** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^
5968 ** The intent of the xInit() method is to set up global data structures
5969 ** required by the custom page cache implementation.
5970 ** ^(If the xInit() method is NULL, then the
5971 ** built-in default page cache is used instead of the application defined
5974 ** [[the xShutdown() page cache method]]
5975 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
5976 ** It can be used to clean up
5977 ** any outstanding resources before process shutdown, if required.
5978 ** ^The xShutdown() method may be NULL.
5980 ** ^SQLite automatically serializes calls to the xInit method,
5981 ** so the xInit method need not be threadsafe. ^The
5982 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
5983 ** not need to be threadsafe either. All other methods must be threadsafe
5984 ** in multithreaded applications.
5986 ** ^SQLite will never invoke xInit() more than once without an intervening
5987 ** call to xShutdown().
5989 ** [[the xCreate() page cache methods]]
5990 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
5991 ** SQLite will typically create one cache instance for each open database file,
5992 ** though this is not guaranteed. ^The
5993 ** first parameter, szPage, is the size in bytes of the pages that must
5994 ** be allocated by the cache. ^szPage will not be a power of two. ^szPage
5995 ** will the page size of the database file that is to be cached plus an
5996 ** increment (here called "R") of less than 250. SQLite will use the
5997 ** extra R bytes on each page to store metadata about the underlying
5998 ** database page on disk. The value of R depends
5999 ** on the SQLite version, the target platform, and how SQLite was compiled.
6000 ** ^(R is constant for a particular build of SQLite. Except, there are two
6001 ** distinct values of R when SQLite is compiled with the proprietary
6002 ** ZIPVFS extension.)^ ^The second argument to
6003 ** xCreate(), bPurgeable, is true if the cache being created will
6004 ** be used to cache database pages of a file stored on disk, or
6005 ** false if it is used for an in-memory database. The cache implementation
6006 ** does not have to do anything special based with the value of bPurgeable;
6007 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
6008 ** never invoke xUnpin() except to deliberately delete a page.
6009 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
6010 ** false will always have the "discard" flag set to true.
6011 ** ^Hence, a cache created with bPurgeable false will
6012 ** never contain any unpinned pages.
6014 ** [[the xCachesize() page cache method]]
6015 ** ^(The xCachesize() method may be called at any time by SQLite to set the
6016 ** suggested maximum cache-size (number of pages stored by) the cache
6017 ** instance passed as the first argument. This is the value configured using
6018 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
6019 ** parameter, the implementation is not required to do anything with this
6020 ** value; it is advisory only.
6022 ** [[the xPagecount() page cache methods]]
6023 ** The xPagecount() method must return the number of pages currently
6024 ** stored in the cache, both pinned and unpinned.
6026 ** [[the xFetch() page cache methods]]
6027 ** The xFetch() method locates a page in the cache and returns a pointer to
6028 ** the page, or a NULL pointer.
6029 ** A "page", in this context, means a buffer of szPage bytes aligned at an
6030 ** 8-byte boundary. The page to be fetched is determined by the key. ^The
6031 ** minimum key value is 1. After it has been retrieved using xFetch, the page
6032 ** is considered to be "pinned".
6034 ** If the requested page is already in the page cache, then the page cache
6035 ** implementation must return a pointer to the page buffer with its content
6036 ** intact. If the requested page is not already in the cache, then the
6037 ** cache implementation should use the value of the createFlag
6038 ** parameter to help it determined what action to take:
6040 ** <table border=1 width=85% align=center>
6041 ** <tr><th> createFlag <th> Behaviour when page is not already in cache
6042 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
6043 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
6044 ** Otherwise return NULL.
6045 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
6046 ** NULL if allocating a new page is effectively impossible.
6049 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
6050 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
6051 ** failed.)^ In between the to xFetch() calls, SQLite may
6052 ** attempt to unpin one or more cache pages by spilling the content of
6053 ** pinned pages to disk and synching the operating system disk cache.
6055 ** [[the xUnpin() page cache method]]
6056 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
6057 ** as its second argument. If the third parameter, discard, is non-zero,
6058 ** then the page must be evicted from the cache.
6059 ** ^If the discard parameter is
6060 ** zero, then the page may be discarded or retained at the discretion of
6061 ** page cache implementation. ^The page cache implementation
6062 ** may choose to evict unpinned pages at any time.
6064 ** The cache must not perform any reference counting. A single
6065 ** call to xUnpin() unpins the page regardless of the number of prior calls
6068 ** [[the xRekey() page cache methods]]
6069 ** The xRekey() method is used to change the key value associated with the
6070 ** page passed as the second argument. If the cache
6071 ** previously contains an entry associated with newKey, it must be
6072 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
6075 ** When SQLite calls the xTruncate() method, the cache must discard all
6076 ** existing cache entries with page numbers (keys) greater than or equal
6077 ** to the value of the iLimit parameter passed to xTruncate(). If any
6078 ** of these pages are pinned, they are implicitly unpinned, meaning that
6079 ** they can be safely discarded.
6081 ** [[the xDestroy() page cache method]]
6082 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
6083 ** All resources associated with the specified cache should be freed. ^After
6084 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
6085 ** handle invalid, and will not use it with any other sqlite3_pcache_methods
6088 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods
;
6089 struct sqlite3_pcache_methods
{
6091 int (*xInit
)(void*);
6092 void (*xShutdown
)(void*);
6093 sqlite3_pcache
*(*xCreate
)(int szPage
, int bPurgeable
);
6094 void (*xCachesize
)(sqlite3_pcache
*, int nCachesize
);
6095 int (*xPagecount
)(sqlite3_pcache
*);
6096 void *(*xFetch
)(sqlite3_pcache
*, unsigned key
, int createFlag
);
6097 void (*xUnpin
)(sqlite3_pcache
*, void*, int discard
);
6098 void (*xRekey
)(sqlite3_pcache
*, void*, unsigned oldKey
, unsigned newKey
);
6099 void (*xTruncate
)(sqlite3_pcache
*, unsigned iLimit
);
6100 void (*xDestroy
)(sqlite3_pcache
*);
6104 ** CAPI3REF: Online Backup Object
6106 ** The sqlite3_backup object records state information about an ongoing
6107 ** online backup operation. ^The sqlite3_backup object is created by
6108 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
6109 ** [sqlite3_backup_finish()].
6111 ** See Also: [Using the SQLite Online Backup API]
6113 typedef struct sqlite3_backup sqlite3_backup
;
6116 ** CAPI3REF: Online Backup API.
6118 ** The backup API copies the content of one database into another.
6119 ** It is useful either for creating backups of databases or
6120 ** for copying in-memory databases to or from persistent files.
6122 ** See Also: [Using the SQLite Online Backup API]
6124 ** ^SQLite holds a write transaction open on the destination database file
6125 ** for the duration of the backup operation.
6126 ** ^The source database is read-locked only while it is being read;
6127 ** it is not locked continuously for the entire backup operation.
6128 ** ^Thus, the backup may be performed on a live source database without
6129 ** preventing other database connections from
6130 ** reading or writing to the source database while the backup is underway.
6132 ** ^(To perform a backup operation:
6134 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
6136 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
6137 ** the data between the two databases, and finally
6138 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
6139 ** associated with the backup operation.
6141 ** There should be exactly one call to sqlite3_backup_finish() for each
6142 ** successful call to sqlite3_backup_init().
6144 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
6146 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
6147 ** [database connection] associated with the destination database
6148 ** and the database name, respectively.
6149 ** ^The database name is "main" for the main database, "temp" for the
6150 ** temporary database, or the name specified after the AS keyword in
6151 ** an [ATTACH] statement for an attached database.
6152 ** ^The S and M arguments passed to
6153 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
6154 ** and database name of the source database, respectively.
6155 ** ^The source and destination [database connections] (parameters S and D)
6156 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
6159 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
6160 ** returned and an error code and error message are stored in the
6161 ** destination [database connection] D.
6162 ** ^The error code and message for the failed call to sqlite3_backup_init()
6163 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
6164 ** [sqlite3_errmsg16()] functions.
6165 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
6166 ** [sqlite3_backup] object.
6167 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
6168 ** sqlite3_backup_finish() functions to perform the specified backup
6171 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
6173 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
6174 ** the source and destination databases specified by [sqlite3_backup] object B.
6175 ** ^If N is negative, all remaining source pages are copied.
6176 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
6177 ** are still more pages to be copied, then the function returns [SQLITE_OK].
6178 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
6179 ** from source to destination, then it returns [SQLITE_DONE].
6180 ** ^If an error occurs while running sqlite3_backup_step(B,N),
6181 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
6182 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
6183 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
6184 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
6186 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
6188 ** <li> the destination database was opened read-only, or
6189 ** <li> the destination database is using write-ahead-log journaling
6190 ** and the destination and source page sizes differ, or
6191 ** <li> the destination database is an in-memory database and the
6192 ** destination and source page sizes differ.
6195 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
6196 ** the [sqlite3_busy_handler | busy-handler function]
6197 ** is invoked (if one is specified). ^If the
6198 ** busy-handler returns non-zero before the lock is available, then
6199 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
6200 ** sqlite3_backup_step() can be retried later. ^If the source
6201 ** [database connection]
6202 ** is being used to write to the source database when sqlite3_backup_step()
6203 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
6204 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
6205 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
6206 ** [SQLITE_READONLY] is returned, then
6207 ** there is no point in retrying the call to sqlite3_backup_step(). These
6208 ** errors are considered fatal.)^ The application must accept
6209 ** that the backup operation has failed and pass the backup operation handle
6210 ** to the sqlite3_backup_finish() to release associated resources.
6212 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
6213 ** on the destination file. ^The exclusive lock is not released until either
6214 ** sqlite3_backup_finish() is called or the backup operation is complete
6215 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
6216 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
6217 ** lasts for the duration of the sqlite3_backup_step() call.
6218 ** ^Because the source database is not locked between calls to
6219 ** sqlite3_backup_step(), the source database may be modified mid-way
6220 ** through the backup process. ^If the source database is modified by an
6221 ** external process or via a database connection other than the one being
6222 ** used by the backup operation, then the backup will be automatically
6223 ** restarted by the next call to sqlite3_backup_step(). ^If the source
6224 ** database is modified by the using the same database connection as is used
6225 ** by the backup operation, then the backup database is automatically
6226 ** updated at the same time.
6228 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
6230 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
6231 ** application wishes to abandon the backup operation, the application
6232 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
6233 ** ^The sqlite3_backup_finish() interfaces releases all
6234 ** resources associated with the [sqlite3_backup] object.
6235 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
6236 ** active write-transaction on the destination database is rolled back.
6237 ** The [sqlite3_backup] object is invalid
6238 ** and may not be used following a call to sqlite3_backup_finish().
6240 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
6241 ** sqlite3_backup_step() errors occurred, regardless or whether or not
6242 ** sqlite3_backup_step() completed.
6243 ** ^If an out-of-memory condition or IO error occurred during any prior
6244 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
6245 ** sqlite3_backup_finish() returns the corresponding [error code].
6247 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
6248 ** is not a permanent error and does not affect the return value of
6249 ** sqlite3_backup_finish().
6251 ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
6252 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
6254 ** ^Each call to sqlite3_backup_step() sets two values inside
6255 ** the [sqlite3_backup] object: the number of pages still to be backed
6256 ** up and the total number of pages in the source database file.
6257 ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
6258 ** retrieve these two values, respectively.
6260 ** ^The values returned by these functions are only updated by
6261 ** sqlite3_backup_step(). ^If the source database is modified during a backup
6262 ** operation, then the values are not updated to account for any extra
6263 ** pages that need to be updated or the size of the source database file
6266 ** <b>Concurrent Usage of Database Handles</b>
6268 ** ^The source [database connection] may be used by the application for other
6269 ** purposes while a backup operation is underway or being initialized.
6270 ** ^If SQLite is compiled and configured to support threadsafe database
6271 ** connections, then the source database connection may be used concurrently
6272 ** from within other threads.
6274 ** However, the application must guarantee that the destination
6275 ** [database connection] is not passed to any other API (by any thread) after
6276 ** sqlite3_backup_init() is called and before the corresponding call to
6277 ** sqlite3_backup_finish(). SQLite does not currently check to see
6278 ** if the application incorrectly accesses the destination [database connection]
6279 ** and so no error code is reported, but the operations may malfunction
6280 ** nevertheless. Use of the destination database connection while a
6281 ** backup is in progress might also also cause a mutex deadlock.
6283 ** If running in [shared cache mode], the application must
6284 ** guarantee that the shared cache used by the destination database
6285 ** is not accessed while the backup is running. In practice this means
6286 ** that the application must guarantee that the disk file being
6287 ** backed up to is not accessed by any connection within the process,
6288 ** not just the specific connection that was passed to sqlite3_backup_init().
6290 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
6291 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
6292 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
6293 ** APIs are not strictly speaking threadsafe. If they are invoked at the
6294 ** same time as another thread is invoking sqlite3_backup_step() it is
6295 ** possible that they return invalid values.
6297 SQLITE_API sqlite3_backup
*sqlite3_backup_init(
6298 sqlite3
*pDest
, /* Destination database handle */
6299 const char *zDestName
, /* Destination database name */
6300 sqlite3
*pSource
, /* Source database handle */
6301 const char *zSourceName
/* Source database name */
6303 SQLITE_API
int sqlite3_backup_step(sqlite3_backup
*p
, int nPage
);
6304 SQLITE_API
int sqlite3_backup_finish(sqlite3_backup
*p
);
6305 SQLITE_API
int sqlite3_backup_remaining(sqlite3_backup
*p
);
6306 SQLITE_API
int sqlite3_backup_pagecount(sqlite3_backup
*p
);
6309 ** CAPI3REF: Unlock Notification
6311 ** ^When running in shared-cache mode, a database operation may fail with
6312 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
6313 ** individual tables within the shared-cache cannot be obtained. See
6314 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
6315 ** ^This API may be used to register a callback that SQLite will invoke
6316 ** when the connection currently holding the required lock relinquishes it.
6317 ** ^This API is only available if the library was compiled with the
6318 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
6320 ** See Also: [Using the SQLite Unlock Notification Feature].
6322 ** ^Shared-cache locks are released when a database connection concludes
6323 ** its current transaction, either by committing it or rolling it back.
6325 ** ^When a connection (known as the blocked connection) fails to obtain a
6326 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
6327 ** identity of the database connection (the blocking connection) that
6328 ** has locked the required resource is stored internally. ^After an
6329 ** application receives an SQLITE_LOCKED error, it may call the
6330 ** sqlite3_unlock_notify() method with the blocked connection handle as
6331 ** the first argument to register for a callback that will be invoked
6332 ** when the blocking connections current transaction is concluded. ^The
6333 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
6334 ** call that concludes the blocking connections transaction.
6336 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
6337 ** there is a chance that the blocking connection will have already
6338 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
6339 ** If this happens, then the specified callback is invoked immediately,
6340 ** from within the call to sqlite3_unlock_notify().)^
6342 ** ^If the blocked connection is attempting to obtain a write-lock on a
6343 ** shared-cache table, and more than one other connection currently holds
6344 ** a read-lock on the same table, then SQLite arbitrarily selects one of
6345 ** the other connections to use as the blocking connection.
6347 ** ^(There may be at most one unlock-notify callback registered by a
6348 ** blocked connection. If sqlite3_unlock_notify() is called when the
6349 ** blocked connection already has a registered unlock-notify callback,
6350 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
6351 ** called with a NULL pointer as its second argument, then any existing
6352 ** unlock-notify callback is canceled. ^The blocked connections
6353 ** unlock-notify callback may also be canceled by closing the blocked
6354 ** connection using [sqlite3_close()].
6356 ** The unlock-notify callback is not reentrant. If an application invokes
6357 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
6358 ** crash or deadlock may be the result.
6360 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
6361 ** returns SQLITE_OK.
6363 ** <b>Callback Invocation Details</b>
6365 ** When an unlock-notify callback is registered, the application provides a
6366 ** single void* pointer that is passed to the callback when it is invoked.
6367 ** However, the signature of the callback function allows SQLite to pass
6368 ** it an array of void* context pointers. The first argument passed to
6369 ** an unlock-notify callback is a pointer to an array of void* pointers,
6370 ** and the second is the number of entries in the array.
6372 ** When a blocking connections transaction is concluded, there may be
6373 ** more than one blocked connection that has registered for an unlock-notify
6374 ** callback. ^If two or more such blocked connections have specified the
6375 ** same callback function, then instead of invoking the callback function
6376 ** multiple times, it is invoked once with the set of void* context pointers
6377 ** specified by the blocked connections bundled together into an array.
6378 ** This gives the application an opportunity to prioritize any actions
6379 ** related to the set of unblocked database connections.
6381 ** <b>Deadlock Detection</b>
6383 ** Assuming that after registering for an unlock-notify callback a
6384 ** database waits for the callback to be issued before taking any further
6385 ** action (a reasonable assumption), then using this API may cause the
6386 ** application to deadlock. For example, if connection X is waiting for
6387 ** connection Y's transaction to be concluded, and similarly connection
6388 ** Y is waiting on connection X's transaction, then neither connection
6389 ** will proceed and the system may remain deadlocked indefinitely.
6391 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
6392 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
6393 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
6394 ** unlock-notify callback is registered. The system is said to be in
6395 ** a deadlocked state if connection A has registered for an unlock-notify
6396 ** callback on the conclusion of connection B's transaction, and connection
6397 ** B has itself registered for an unlock-notify callback when connection
6398 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
6399 ** the system is also considered to be deadlocked if connection B has
6400 ** registered for an unlock-notify callback on the conclusion of connection
6401 ** C's transaction, where connection C is waiting on connection A. ^Any
6402 ** number of levels of indirection are allowed.
6404 ** <b>The "DROP TABLE" Exception</b>
6406 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
6407 ** always appropriate to call sqlite3_unlock_notify(). There is however,
6408 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
6409 ** SQLite checks if there are any currently executing SELECT statements
6410 ** that belong to the same connection. If there are, SQLITE_LOCKED is
6411 ** returned. In this case there is no "blocking connection", so invoking
6412 ** sqlite3_unlock_notify() results in the unlock-notify callback being
6413 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
6414 ** or "DROP INDEX" query, an infinite loop might be the result.
6416 ** One way around this problem is to check the extended error code returned
6417 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
6418 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
6419 ** the special "DROP TABLE/INDEX" case, the extended error code is just
6422 SQLITE_API
int sqlite3_unlock_notify(
6423 sqlite3
*pBlocked
, /* Waiting connection */
6424 void (*xNotify
)(void **apArg
, int nArg
), /* Callback function to invoke */
6425 void *pNotifyArg
/* Argument to pass to xNotify */
6430 ** CAPI3REF: String Comparison
6432 ** ^The [sqlite3_strnicmp()] API allows applications and extensions to
6433 ** compare the contents of two buffers containing UTF-8 strings in a
6434 ** case-independent fashion, using the same definition of case independence
6435 ** that SQLite uses internally when comparing identifiers.
6437 SQLITE_API
int sqlite3_strnicmp(const char *, const char *, int);
6440 ** CAPI3REF: Error Logging Interface
6442 ** ^The [sqlite3_log()] interface writes a message into the error log
6443 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
6444 ** ^If logging is enabled, the zFormat string and subsequent arguments are
6445 ** used with [sqlite3_snprintf()] to generate the final output string.
6447 ** The sqlite3_log() interface is intended for use by extensions such as
6448 ** virtual tables, collating functions, and SQL functions. While there is
6449 ** nothing to prevent an application from calling sqlite3_log(), doing so
6450 ** is considered bad form.
6452 ** The zFormat string must not be NULL.
6454 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
6455 ** will not use dynamically allocated memory. The log message is stored in
6456 ** a fixed-length buffer on the stack. If the log message is longer than
6457 ** a few hundred characters, it will be truncated to the length of the
6460 SQLITE_API
void sqlite3_log(int iErrCode
, const char *zFormat
, ...);
6463 ** CAPI3REF: Write-Ahead Log Commit Hook
6465 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
6466 ** will be invoked each time a database connection commits data to a
6467 ** [write-ahead log] (i.e. whenever a transaction is committed in
6468 ** [journal_mode | journal_mode=WAL mode]).
6470 ** ^The callback is invoked by SQLite after the commit has taken place and
6471 ** the associated write-lock on the database released, so the implementation
6472 ** may read, write or [checkpoint] the database as required.
6474 ** ^The first parameter passed to the callback function when it is invoked
6475 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
6476 ** registering the callback. ^The second is a copy of the database handle.
6477 ** ^The third parameter is the name of the database that was written to -
6478 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
6479 ** is the number of pages currently in the write-ahead log file,
6480 ** including those that were just committed.
6482 ** The callback function should normally return [SQLITE_OK]. ^If an error
6483 ** code is returned, that error will propagate back up through the
6484 ** SQLite code base to cause the statement that provoked the callback
6485 ** to report an error, though the commit will have still occurred. If the
6486 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
6487 ** that does not correspond to any valid SQLite error code, the results
6490 ** A single database handle may have at most a single write-ahead log callback
6491 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
6492 ** previously registered write-ahead log callback. ^Note that the
6493 ** [sqlite3_wal_autocheckpoint()] interface and the
6494 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
6495 ** those overwrite any prior [sqlite3_wal_hook()] settings.
6497 SQLITE_API
void *sqlite3_wal_hook(
6499 int(*)(void *,sqlite3
*,const char*,int),
6504 ** CAPI3REF: Configure an auto-checkpoint
6506 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
6507 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
6508 ** to automatically [checkpoint]
6509 ** after committing a transaction if there are N or
6510 ** more frames in the [write-ahead log] file. ^Passing zero or
6511 ** a negative value as the nFrame parameter disables automatic
6512 ** checkpoints entirely.
6514 ** ^The callback registered by this function replaces any existing callback
6515 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
6516 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
6517 ** configured by this function.
6519 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
6522 ** ^Every new [database connection] defaults to having the auto-checkpoint
6523 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
6524 ** pages. The use of this interface
6525 ** is only necessary if the default setting is found to be suboptimal
6526 ** for a particular application.
6528 SQLITE_API
int sqlite3_wal_autocheckpoint(sqlite3
*db
, int N
);
6531 ** CAPI3REF: Checkpoint a database
6533 ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
6534 ** on [database connection] D to be [checkpointed]. ^If X is NULL or an
6535 ** empty string, then a checkpoint is run on all databases of
6536 ** connection D. ^If the database connection D is not in
6537 ** [WAL | write-ahead log mode] then this interface is a harmless no-op.
6539 ** ^The [wal_checkpoint pragma] can be used to invoke this interface
6540 ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the
6541 ** [wal_autocheckpoint pragma] can be used to cause this interface to be
6542 ** run whenever the WAL reaches a certain size threshold.
6544 ** See also: [sqlite3_wal_checkpoint_v2()]
6546 SQLITE_API
int sqlite3_wal_checkpoint(sqlite3
*db
, const char *zDb
);
6549 ** CAPI3REF: Checkpoint a database
6551 ** Run a checkpoint operation on WAL database zDb attached to database
6552 ** handle db. The specific operation is determined by the value of the
6556 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
6557 ** Checkpoint as many frames as possible without waiting for any database
6558 ** readers or writers to finish. Sync the db file if all frames in the log
6559 ** are checkpointed. This mode is the same as calling
6560 ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
6562 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
6563 ** This mode blocks (calls the busy-handler callback) until there is no
6564 ** database writer and all readers are reading from the most recent database
6565 ** snapshot. It then checkpoints all frames in the log file and syncs the
6566 ** database file. This call blocks database writers while it is running,
6567 ** but not database readers.
6569 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
6570 ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
6571 ** checkpointing the log file it blocks (calls the busy-handler callback)
6572 ** until all readers are reading from the database file only. This ensures
6573 ** that the next client to write to the database file restarts the log file
6574 ** from the beginning. This call blocks database writers while it is running,
6575 ** but not database readers.
6578 ** If pnLog is not NULL, then *pnLog is set to the total number of frames in
6579 ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
6580 ** the total number of checkpointed frames (including any that were already
6581 ** checkpointed when this function is called). *pnLog and *pnCkpt may be
6582 ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
6583 ** If no values are available because of an error, they are both set to -1
6584 ** before returning to communicate this to the caller.
6586 ** All calls obtain an exclusive "checkpoint" lock on the database file. If
6587 ** any other process is running a checkpoint operation at the same time, the
6588 ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
6589 ** busy-handler configured, it will not be invoked in this case.
6591 ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
6592 ** "writer" lock on the database file. If the writer lock cannot be obtained
6593 ** immediately, and a busy-handler is configured, it is invoked and the writer
6594 ** lock retried until either the busy-handler returns 0 or the lock is
6595 ** successfully obtained. The busy-handler is also invoked while waiting for
6596 ** database readers as described above. If the busy-handler returns 0 before
6597 ** the writer lock is obtained or while waiting for database readers, the
6598 ** checkpoint operation proceeds from that point in the same way as
6599 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
6600 ** without blocking any further. SQLITE_BUSY is returned in this case.
6602 ** If parameter zDb is NULL or points to a zero length string, then the
6603 ** specified operation is attempted on all WAL databases. In this case the
6604 ** values written to output parameters *pnLog and *pnCkpt are undefined. If
6605 ** an SQLITE_BUSY error is encountered when processing one or more of the
6606 ** attached WAL databases, the operation is still attempted on any remaining
6607 ** attached databases and SQLITE_BUSY is returned to the caller. If any other
6608 ** error occurs while processing an attached database, processing is abandoned
6609 ** and the error code returned to the caller immediately. If no error
6610 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
6611 ** databases, SQLITE_OK is returned.
6613 ** If database zDb is the name of an attached database that is not in WAL
6614 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
6615 ** zDb is not NULL (or a zero length string) and is not the name of any
6616 ** attached database, SQLITE_ERROR is returned to the caller.
6618 SQLITE_API
int sqlite3_wal_checkpoint_v2(
6619 sqlite3
*db
, /* Database handle */
6620 const char *zDb
, /* Name of attached database (or NULL) */
6621 int eMode
, /* SQLITE_CHECKPOINT_* value */
6622 int *pnLog
, /* OUT: Size of WAL log in frames */
6623 int *pnCkpt
/* OUT: Total number of frames checkpointed */
6627 ** CAPI3REF: Checkpoint operation parameters
6629 ** These constants can be used as the 3rd parameter to
6630 ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()]
6631 ** documentation for additional information about the meaning and use of
6632 ** each of these values.
6634 #define SQLITE_CHECKPOINT_PASSIVE 0
6635 #define SQLITE_CHECKPOINT_FULL 1
6636 #define SQLITE_CHECKPOINT_RESTART 2
6639 ** CAPI3REF: Virtual Table Interface Configuration
6641 ** This function may be called by either the [xConnect] or [xCreate] method
6642 ** of a [virtual table] implementation to configure
6643 ** various facets of the virtual table interface.
6645 ** If this interface is invoked outside the context of an xConnect or
6646 ** xCreate virtual table method then the behavior is undefined.
6648 ** At present, there is only one option that may be configured using
6649 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
6650 ** may be added in the future.
6652 SQLITE_API
int sqlite3_vtab_config(sqlite3
*, int op
, ...);
6655 ** CAPI3REF: Virtual Table Configuration Options
6657 ** These macros define the various options to the
6658 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
6659 ** can use to customize and optimize their behavior.
6662 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
6663 ** <dd>Calls of the form
6664 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
6665 ** where X is an integer. If X is zero, then the [virtual table] whose
6666 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
6667 ** support constraints. In this configuration (which is the default) if
6668 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
6669 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
6670 ** specified as part of the users SQL statement, regardless of the actual
6671 ** ON CONFLICT mode specified.
6673 ** If X is non-zero, then the virtual table implementation guarantees
6674 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
6675 ** any modifications to internal or persistent data structures have been made.
6676 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
6677 ** is able to roll back a statement or database transaction, and abandon
6678 ** or continue processing the current SQL statement as appropriate.
6679 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
6680 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
6683 ** Virtual table implementations that are required to handle OR REPLACE
6684 ** must do so within the [xUpdate] method. If a call to the
6685 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
6686 ** CONFLICT policy is REPLACE, the virtual table implementation should
6687 ** silently replace the appropriate rows within the xUpdate callback and
6688 ** return SQLITE_OK. Or, if this is not possible, it may return
6689 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
6690 ** constraint handling.
6693 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
6696 ** CAPI3REF: Determine The Virtual Table Conflict Policy
6698 ** This function may only be called from within a call to the [xUpdate] method
6699 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
6700 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
6701 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
6702 ** of the SQL statement that triggered the call to the [xUpdate] method of the
6705 SQLITE_API
int sqlite3_vtab_on_conflict(sqlite3
*);
6708 ** CAPI3REF: Conflict resolution modes
6710 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
6711 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
6712 ** is for the SQL statement being evaluated.
6714 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
6715 ** return value from the [sqlite3_set_authorizer()] callback and that
6716 ** [SQLITE_ABORT] is also a [result code].
6718 #define SQLITE_ROLLBACK 1
6719 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
6720 #define SQLITE_FAIL 3
6721 /* #define SQLITE_ABORT 4 // Also an error code */
6722 #define SQLITE_REPLACE 5
6727 ** Undo the hack that converts floating point types to integer for
6728 ** builds on processors without floating point support.
6730 #ifdef SQLITE_OMIT_FLOATING_POINT
6735 } /* End of the 'extern "C"' block */
6742 ** The author disclaims copyright to this source code. In place of
6743 ** a legal notice, here is a blessing:
6745 ** May you do good and not evil.
6746 ** May you find forgiveness for yourself and forgive others.
6747 ** May you share freely, never taking more than you give.
6749 *************************************************************************
6752 #ifndef _SQLITE3RTREE_H_
6753 #define _SQLITE3RTREE_H_
6760 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry
;
6763 ** Register a geometry callback named zGeom that can be used as part of an
6764 ** R-Tree geometry query as follows:
6766 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
6768 SQLITE_API
int sqlite3_rtree_geometry_callback(
6771 int (*xGeom
)(sqlite3_rtree_geometry
*, int nCoord
, double *aCoord
, int *pRes
),
6777 ** A pointer to a structure of the following type is passed as the first
6778 ** argument to callbacks registered using rtree_geometry_callback().
6780 struct sqlite3_rtree_geometry
{
6781 void *pContext
; /* Copy of pContext passed to s_r_g_c() */
6782 int nParam
; /* Size of array aParam[] */
6783 double *aParam
; /* Parameters passed to SQL geom function */
6784 void *pUser
; /* Callback implementation user data */
6785 void (*xDelUser
)(void *); /* Called by SQLite to clean up pUser */
6790 } /* end of the 'extern "C"' block */
6793 #endif /* ifndef _SQLITE3RTREE_H_ */