1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are suppose to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef _SQLITE3_H_ 34#define _SQLITE3_H_ 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Add the ability to override 'extern' 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51 52/* 53** These no-op macros are used in front of interfaces to mark those 54** interfaces as either deprecated or experimental. New applications 55** should not use deprecated interfaces - they are support for backwards 56** compatibility only. Application writers should be aware that 57** experimental interfaces are subject to change in point releases. 58** 59** These macros used to resolve to various kinds of compiler magic that 60** would generate warning messages when they were used. But that 61** compiler magic ended up generating such a flurry of bug reports 62** that we have taken it all out and gone back to using simple 63** noop macros. 64*/ 65#define SQLITE_DEPRECATED 66#define SQLITE_EXPERIMENTAL 67 68/* 69** Ensure these symbols were not defined by some previous header file. 70*/ 71#ifdef SQLITE_VERSION 72# undef SQLITE_VERSION 73#endif 74#ifdef SQLITE_VERSION_NUMBER 75# undef SQLITE_VERSION_NUMBER 76#endif 77 78/* 79** CAPI3REF: Compile-Time Library Version Numbers 80** 81** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 82** evaluates to a string literal that is the SQLite version in the 83** format "X.Y.Z" where X is the major version number (always 3 for 84** SQLite3) and Y is the minor version number and Z is the release number.)^ 85** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 86** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 87** numbers used in [SQLITE_VERSION].)^ 88** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 89** be larger than the release from which it is derived. Either Y will 90** be held constant and Z will be incremented or else Y will be incremented 91** and Z will be reset to zero. 92** 93** Since version 3.6.18, SQLite source code has been stored in the 94** <a href="http://www.fossil-scm.org/">Fossil configuration management 95** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 96** a string which identifies a particular check-in of SQLite 97** within its configuration management system. ^The SQLITE_SOURCE_ID 98** string contains the date and time of the check-in (UTC) and an SHA1 99** hash of the entire source tree. 100** 101** See also: [sqlite3_libversion()], 102** [sqlite3_libversion_number()], [sqlite3_sourceid()], 103** [sqlite_version()] and [sqlite_source_id()]. 104*/ 105#define SQLITE_VERSION "--VERS--" 106#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 107#define SQLITE_SOURCE_ID "--SOURCE-ID--" 108 109/* 110** CAPI3REF: Run-Time Library Version Numbers 111** KEYWORDS: sqlite3_version, sqlite3_sourceid 112** 113** These interfaces provide the same information as the [SQLITE_VERSION], 114** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 115** but are associated with the library instead of the header file. ^(Cautious 116** programmers might include assert() statements in their application to 117** verify that values returned by these interfaces match the macros in 118** the header, and thus insure that the application is 119** compiled with matching library and header files. 120** 121** <blockquote><pre> 122** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 123** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 124** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 125** </pre></blockquote>)^ 126** 127** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 128** macro. ^The sqlite3_libversion() function returns a pointer to the 129** to the sqlite3_version[] string constant. The sqlite3_libversion() 130** function is provided for use in DLLs since DLL users usually do not have 131** direct access to string constants within the DLL. ^The 132** sqlite3_libversion_number() function returns an integer equal to 133** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 134** a pointer to a string constant whose value is the same as the 135** [SQLITE_SOURCE_ID] C preprocessor macro. 136** 137** See also: [sqlite_version()] and [sqlite_source_id()]. 138*/ 139SQLITE_EXTERN const char sqlite3_version[]; 140const char *sqlite3_libversion(void); 141const char *sqlite3_sourceid(void); 142int sqlite3_libversion_number(void); 143 144/* 145** CAPI3REF: Run-Time Library Compilation Options Diagnostics 146** 147** ^The sqlite3_compileoption_used() function returns 0 or 1 148** indicating whether the specified option was defined at 149** compile time. ^The SQLITE_ prefix may be omitted from the 150** option name passed to sqlite3_compileoption_used(). 151** 152** ^The sqlite3_compileoption_get() function allows iterating 153** over the list of options that were defined at compile time by 154** returning the N-th compile time option string. ^If N is out of range, 155** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 156** prefix is omitted from any strings returned by 157** sqlite3_compileoption_get(). 158** 159** ^Support for the diagnostic functions sqlite3_compileoption_used() 160** and sqlite3_compileoption_get() may be omitted by specifying the 161** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 162** 163** See also: SQL functions [sqlite_compileoption_used()] and 164** [sqlite_compileoption_get()] and the [compile_options pragma]. 165*/ 166#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 167int sqlite3_compileoption_used(const char *zOptName); 168const char *sqlite3_compileoption_get(int N); 169#endif 170 171/* 172** CAPI3REF: Test To See If The Library Is Threadsafe 173** 174** ^The sqlite3_threadsafe() function returns zero if and only if 175** SQLite was compiled with mutexing code omitted due to the 176** [SQLITE_THREADSAFE] compile-time option being set to 0. 177** 178** SQLite can be compiled with or without mutexes. When 179** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 180** are enabled and SQLite is threadsafe. When the 181** [SQLITE_THREADSAFE] macro is 0, 182** the mutexes are omitted. Without the mutexes, it is not safe 183** to use SQLite concurrently from more than one thread. 184** 185** Enabling mutexes incurs a measurable performance penalty. 186** So if speed is of utmost importance, it makes sense to disable 187** the mutexes. But for maximum safety, mutexes should be enabled. 188** ^The default behavior is for mutexes to be enabled. 189** 190** This interface can be used by an application to make sure that the 191** version of SQLite that it is linking against was compiled with 192** the desired setting of the [SQLITE_THREADSAFE] macro. 193** 194** This interface only reports on the compile-time mutex setting 195** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 196** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 197** can be fully or partially disabled using a call to [sqlite3_config()] 198** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 199** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 200** sqlite3_threadsafe() function shows only the compile-time setting of 201** thread safety, not any run-time changes to that setting made by 202** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 203** is unchanged by calls to sqlite3_config().)^ 204** 205** See the [threading mode] documentation for additional information. 206*/ 207int sqlite3_threadsafe(void); 208 209/* 210** CAPI3REF: Database Connection Handle 211** KEYWORDS: {database connection} {database connections} 212** 213** Each open SQLite database is represented by a pointer to an instance of 214** the opaque structure named "sqlite3". It is useful to think of an sqlite3 215** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 216** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 217** and [sqlite3_close_v2()] are its destructors. There are many other 218** interfaces (such as 219** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 220** [sqlite3_busy_timeout()] to name but three) that are methods on an 221** sqlite3 object. 222*/ 223typedef struct sqlite3 sqlite3; 224 225/* 226** CAPI3REF: 64-Bit Integer Types 227** KEYWORDS: sqlite_int64 sqlite_uint64 228** 229** Because there is no cross-platform way to specify 64-bit integer types 230** SQLite includes typedefs for 64-bit signed and unsigned integers. 231** 232** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 233** The sqlite_int64 and sqlite_uint64 types are supported for backwards 234** compatibility only. 235** 236** ^The sqlite3_int64 and sqlite_int64 types can store integer values 237** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 238** sqlite3_uint64 and sqlite_uint64 types can store integer values 239** between 0 and +18446744073709551615 inclusive. 240*/ 241#ifdef SQLITE_INT64_TYPE 242 typedef SQLITE_INT64_TYPE sqlite_int64; 243 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 244#elif defined(_MSC_VER) || defined(__BORLANDC__) 245 typedef __int64 sqlite_int64; 246 typedef unsigned __int64 sqlite_uint64; 247#else 248 typedef long long int sqlite_int64; 249 typedef unsigned long long int sqlite_uint64; 250#endif 251typedef sqlite_int64 sqlite3_int64; 252typedef sqlite_uint64 sqlite3_uint64; 253 254/* 255** If compiling for a processor that lacks floating point support, 256** substitute integer for floating-point. 257*/ 258#ifdef SQLITE_OMIT_FLOATING_POINT 259# define double sqlite3_int64 260#endif 261 262/* 263** CAPI3REF: Closing A Database Connection 264** 265** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 266** for the [sqlite3] object. 267** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if 268** the [sqlite3] object is successfully destroyed and all associated 269** resources are deallocated. 270** 271** ^If the database connection is associated with unfinalized prepared 272** statements or unfinished sqlite3_backup objects then sqlite3_close() 273** will leave the database connection open and return [SQLITE_BUSY]. 274** ^If sqlite3_close_v2() is called with unfinalized prepared statements 275** and unfinished sqlite3_backups, then the database connection becomes 276** an unusable "zombie" which will automatically be deallocated when the 277** last prepared statement is finalized or the last sqlite3_backup is 278** finished. The sqlite3_close_v2() interface is intended for use with 279** host languages that are garbage collected, and where the order in which 280** destructors are called is arbitrary. 281** 282** Applications should [sqlite3_finalize | finalize] all [prepared statements], 283** [sqlite3_blob_close | close] all [BLOB handles], and 284** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 285** with the [sqlite3] object prior to attempting to close the object. ^If 286** sqlite3_close() is called on a [database connection] that still has 287** outstanding [prepared statements], [BLOB handles], and/or 288** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation 289** of resources is deferred until all [prepared statements], [BLOB handles], 290** and [sqlite3_backup] objects are also destroyed. 291** 292** ^If an [sqlite3] object is destroyed while a transaction is open, 293** the transaction is automatically rolled back. 294** 295** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 296** must be either a NULL 297** pointer or an [sqlite3] object pointer obtained 298** from [sqlite3_open()], [sqlite3_open16()], or 299** [sqlite3_open_v2()], and not previously closed. 300** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 301** argument is a harmless no-op. 302*/ 303int sqlite3_close(sqlite3*); 304int sqlite3_close_v2(sqlite3*); 305 306/* 307** The type for a callback function. 308** This is legacy and deprecated. It is included for historical 309** compatibility and is not documented. 310*/ 311typedef int (*sqlite3_callback)(void*,int,char**, char**); 312 313/* 314** CAPI3REF: One-Step Query Execution Interface 315** 316** The sqlite3_exec() interface is a convenience wrapper around 317** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 318** that allows an application to run multiple statements of SQL 319** without having to use a lot of C code. 320** 321** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 322** semicolon-separate SQL statements passed into its 2nd argument, 323** in the context of the [database connection] passed in as its 1st 324** argument. ^If the callback function of the 3rd argument to 325** sqlite3_exec() is not NULL, then it is invoked for each result row 326** coming out of the evaluated SQL statements. ^The 4th argument to 327** sqlite3_exec() is relayed through to the 1st argument of each 328** callback invocation. ^If the callback pointer to sqlite3_exec() 329** is NULL, then no callback is ever invoked and result rows are 330** ignored. 331** 332** ^If an error occurs while evaluating the SQL statements passed into 333** sqlite3_exec(), then execution of the current statement stops and 334** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 335** is not NULL then any error message is written into memory obtained 336** from [sqlite3_malloc()] and passed back through the 5th parameter. 337** To avoid memory leaks, the application should invoke [sqlite3_free()] 338** on error message strings returned through the 5th parameter of 339** of sqlite3_exec() after the error message string is no longer needed. 340** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 341** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 342** NULL before returning. 343** 344** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 345** routine returns SQLITE_ABORT without invoking the callback again and 346** without running any subsequent SQL statements. 347** 348** ^The 2nd argument to the sqlite3_exec() callback function is the 349** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 350** callback is an array of pointers to strings obtained as if from 351** [sqlite3_column_text()], one for each column. ^If an element of a 352** result row is NULL then the corresponding string pointer for the 353** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 354** sqlite3_exec() callback is an array of pointers to strings where each 355** entry represents the name of corresponding result column as obtained 356** from [sqlite3_column_name()]. 357** 358** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 359** to an empty string, or a pointer that contains only whitespace and/or 360** SQL comments, then no SQL statements are evaluated and the database 361** is not changed. 362** 363** Restrictions: 364** 365** <ul> 366** <li> The application must insure that the 1st parameter to sqlite3_exec() 367** is a valid and open [database connection]. 368** <li> The application must not close [database connection] specified by 369** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 370** <li> The application must not modify the SQL statement text passed into 371** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 372** </ul> 373*/ 374int sqlite3_exec( 375 sqlite3*, /* An open database */ 376 const char *sql, /* SQL to be evaluated */ 377 int (*callback)(void*,int,char**,char**), /* Callback function */ 378 void *, /* 1st argument to callback */ 379 char **errmsg /* Error msg written here */ 380); 381 382/* 383** CAPI3REF: Result Codes 384** KEYWORDS: SQLITE_OK {error code} {error codes} 385** KEYWORDS: {result code} {result codes} 386** 387** Many SQLite functions return an integer result code from the set shown 388** here in order to indicate success or failure. 389** 390** New error codes may be added in future versions of SQLite. 391** 392** See also: [SQLITE_IOERR_READ | extended result codes], 393** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. 394*/ 395#define SQLITE_OK 0 /* Successful result */ 396/* beginning-of-error-codes */ 397#define SQLITE_ERROR 1 /* SQL error or missing database */ 398#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 399#define SQLITE_PERM 3 /* Access permission denied */ 400#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 401#define SQLITE_BUSY 5 /* The database file is locked */ 402#define SQLITE_LOCKED 6 /* A table in the database is locked */ 403#define SQLITE_NOMEM 7 /* A malloc() failed */ 404#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 405#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 406#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 407#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 408#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 409#define SQLITE_FULL 13 /* Insertion failed because database is full */ 410#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 411#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 412#define SQLITE_EMPTY 16 /* Database is empty */ 413#define SQLITE_SCHEMA 17 /* The database schema changed */ 414#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 415#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 416#define SQLITE_MISMATCH 20 /* Data type mismatch */ 417#define SQLITE_MISUSE 21 /* Library used incorrectly */ 418#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 419#define SQLITE_AUTH 23 /* Authorization denied */ 420#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 421#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 422#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 423#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 424#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 425/* end-of-error-codes */ 426 427/* 428** CAPI3REF: Extended Result Codes 429** KEYWORDS: {extended error code} {extended error codes} 430** KEYWORDS: {extended result code} {extended result codes} 431** 432** In its default configuration, SQLite API routines return one of 26 integer 433** [SQLITE_OK | result codes]. However, experience has shown that many of 434** these result codes are too coarse-grained. They do not provide as 435** much information about problems as programmers might like. In an effort to 436** address this, newer versions of SQLite (version 3.3.8 and later) include 437** support for additional result codes that provide more detailed information 438** about errors. The extended result codes are enabled or disabled 439** on a per database connection basis using the 440** [sqlite3_extended_result_codes()] API. 441** 442** Some of the available extended result codes are listed here. 443** One may expect the number of extended result codes will be expand 444** over time. Software that uses extended result codes should expect 445** to see new result codes in future releases of SQLite. 446** 447** The SQLITE_OK result code will never be extended. It will always 448** be exactly zero. 449*/ 450#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 451#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 452#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 453#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 454#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 455#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 456#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 457#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 458#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 459#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 460#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 461#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 462#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 463#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 464#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 465#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 466#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 467#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 468#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 469#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 470#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 471#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 472#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 473#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 474#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 475#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 476#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 477#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 478#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 479#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 480 481/* 482** CAPI3REF: Flags For File Open Operations 483** 484** These bit values are intended for use in the 485** 3rd parameter to the [sqlite3_open_v2()] interface and 486** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 487*/ 488#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 489#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 490#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 491#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 492#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 493#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 494#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 495#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 496#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 497#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 498#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 499#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 500#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 501#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 502#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 503#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 504#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 505#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 506#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 507#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 508 509/* Reserved: 0x00F00000 */ 510 511/* 512** CAPI3REF: Device Characteristics 513** 514** The xDeviceCharacteristics method of the [sqlite3_io_methods] 515** object returns an integer which is a vector of these 516** bit values expressing I/O characteristics of the mass storage 517** device that holds the file that the [sqlite3_io_methods] 518** refers to. 519** 520** The SQLITE_IOCAP_ATOMIC property means that all writes of 521** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 522** mean that writes of blocks that are nnn bytes in size and 523** are aligned to an address which is an integer multiple of 524** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 525** that when data is appended to a file, the data is appended 526** first then the size of the file is extended, never the other 527** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 528** information is written to disk in the same order as calls 529** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 530** after reboot following a crash or power loss, the only bytes in a 531** file that were written at the application level might have changed 532** and that adjacent bytes, even bytes within the same sector are 533** guaranteed to be unchanged. 534*/ 535#define SQLITE_IOCAP_ATOMIC 0x00000001 536#define SQLITE_IOCAP_ATOMIC512 0x00000002 537#define SQLITE_IOCAP_ATOMIC1K 0x00000004 538#define SQLITE_IOCAP_ATOMIC2K 0x00000008 539#define SQLITE_IOCAP_ATOMIC4K 0x00000010 540#define SQLITE_IOCAP_ATOMIC8K 0x00000020 541#define SQLITE_IOCAP_ATOMIC16K 0x00000040 542#define SQLITE_IOCAP_ATOMIC32K 0x00000080 543#define SQLITE_IOCAP_ATOMIC64K 0x00000100 544#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 545#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 546#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 547#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 548 549/* 550** CAPI3REF: File Locking Levels 551** 552** SQLite uses one of these integer values as the second 553** argument to calls it makes to the xLock() and xUnlock() methods 554** of an [sqlite3_io_methods] object. 555*/ 556#define SQLITE_LOCK_NONE 0 557#define SQLITE_LOCK_SHARED 1 558#define SQLITE_LOCK_RESERVED 2 559#define SQLITE_LOCK_PENDING 3 560#define SQLITE_LOCK_EXCLUSIVE 4 561 562/* 563** CAPI3REF: Synchronization Type Flags 564** 565** When SQLite invokes the xSync() method of an 566** [sqlite3_io_methods] object it uses a combination of 567** these integer values as the second argument. 568** 569** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 570** sync operation only needs to flush data to mass storage. Inode 571** information need not be flushed. If the lower four bits of the flag 572** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 573** If the lower four bits equal SQLITE_SYNC_FULL, that means 574** to use Mac OS X style fullsync instead of fsync(). 575** 576** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 577** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 578** settings. The [synchronous pragma] determines when calls to the 579** xSync VFS method occur and applies uniformly across all platforms. 580** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 581** energetic or rigorous or forceful the sync operations are and 582** only make a difference on Mac OSX for the default SQLite code. 583** (Third-party VFS implementations might also make the distinction 584** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 585** operating systems natively supported by SQLite, only Mac OSX 586** cares about the difference.) 587*/ 588#define SQLITE_SYNC_NORMAL 0x00002 589#define SQLITE_SYNC_FULL 0x00003 590#define SQLITE_SYNC_DATAONLY 0x00010 591 592/* 593** CAPI3REF: OS Interface Open File Handle 594** 595** An [sqlite3_file] object represents an open file in the 596** [sqlite3_vfs | OS interface layer]. Individual OS interface 597** implementations will 598** want to subclass this object by appending additional fields 599** for their own use. The pMethods entry is a pointer to an 600** [sqlite3_io_methods] object that defines methods for performing 601** I/O operations on the open file. 602*/ 603typedef struct sqlite3_file sqlite3_file; 604struct sqlite3_file { 605 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 606}; 607 608/* 609** CAPI3REF: OS Interface File Virtual Methods Object 610** 611** Every file opened by the [sqlite3_vfs.xOpen] method populates an 612** [sqlite3_file] object (or, more commonly, a subclass of the 613** [sqlite3_file] object) with a pointer to an instance of this object. 614** This object defines the methods used to perform various operations 615** against the open file represented by the [sqlite3_file] object. 616** 617** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 618** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 619** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 620** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 621** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 622** to NULL. 623** 624** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 625** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 626** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 627** flag may be ORed in to indicate that only the data of the file 628** and not its inode needs to be synced. 629** 630** The integer values to xLock() and xUnlock() are one of 631** <ul> 632** <li> [SQLITE_LOCK_NONE], 633** <li> [SQLITE_LOCK_SHARED], 634** <li> [SQLITE_LOCK_RESERVED], 635** <li> [SQLITE_LOCK_PENDING], or 636** <li> [SQLITE_LOCK_EXCLUSIVE]. 637** </ul> 638** xLock() increases the lock. xUnlock() decreases the lock. 639** The xCheckReservedLock() method checks whether any database connection, 640** either in this process or in some other process, is holding a RESERVED, 641** PENDING, or EXCLUSIVE lock on the file. It returns true 642** if such a lock exists and false otherwise. 643** 644** The xFileControl() method is a generic interface that allows custom 645** VFS implementations to directly control an open file using the 646** [sqlite3_file_control()] interface. The second "op" argument is an 647** integer opcode. The third argument is a generic pointer intended to 648** point to a structure that may contain arguments or space in which to 649** write return values. Potential uses for xFileControl() might be 650** functions to enable blocking locks with timeouts, to change the 651** locking strategy (for example to use dot-file locks), to inquire 652** about the status of a lock, or to break stale locks. The SQLite 653** core reserves all opcodes less than 100 for its own use. 654** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 655** Applications that define a custom xFileControl method should use opcodes 656** greater than 100 to avoid conflicts. VFS implementations should 657** return [SQLITE_NOTFOUND] for file control opcodes that they do not 658** recognize. 659** 660** The xSectorSize() method returns the sector size of the 661** device that underlies the file. The sector size is the 662** minimum write that can be performed without disturbing 663** other bytes in the file. The xDeviceCharacteristics() 664** method returns a bit vector describing behaviors of the 665** underlying device: 666** 667** <ul> 668** <li> [SQLITE_IOCAP_ATOMIC] 669** <li> [SQLITE_IOCAP_ATOMIC512] 670** <li> [SQLITE_IOCAP_ATOMIC1K] 671** <li> [SQLITE_IOCAP_ATOMIC2K] 672** <li> [SQLITE_IOCAP_ATOMIC4K] 673** <li> [SQLITE_IOCAP_ATOMIC8K] 674** <li> [SQLITE_IOCAP_ATOMIC16K] 675** <li> [SQLITE_IOCAP_ATOMIC32K] 676** <li> [SQLITE_IOCAP_ATOMIC64K] 677** <li> [SQLITE_IOCAP_SAFE_APPEND] 678** <li> [SQLITE_IOCAP_SEQUENTIAL] 679** </ul> 680** 681** The SQLITE_IOCAP_ATOMIC property means that all writes of 682** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 683** mean that writes of blocks that are nnn bytes in size and 684** are aligned to an address which is an integer multiple of 685** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 686** that when data is appended to a file, the data is appended 687** first then the size of the file is extended, never the other 688** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 689** information is written to disk in the same order as calls 690** to xWrite(). 691** 692** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 693** in the unread portions of the buffer with zeros. A VFS that 694** fails to zero-fill short reads might seem to work. However, 695** failure to zero-fill short reads will eventually lead to 696** database corruption. 697*/ 698typedef struct sqlite3_io_methods sqlite3_io_methods; 699struct sqlite3_io_methods { 700 int iVersion; 701 int (*xClose)(sqlite3_file*); 702 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 703 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 704 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 705 int (*xSync)(sqlite3_file*, int flags); 706 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 707 int (*xLock)(sqlite3_file*, int); 708 int (*xUnlock)(sqlite3_file*, int); 709 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 710 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 711 int (*xSectorSize)(sqlite3_file*); 712 int (*xDeviceCharacteristics)(sqlite3_file*); 713 /* Methods above are valid for version 1 */ 714 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 715 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 716 void (*xShmBarrier)(sqlite3_file*); 717 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 718 /* Methods above are valid for version 2 */ 719 /* Additional methods may be added in future releases */ 720}; 721 722/* 723** CAPI3REF: Standard File Control Opcodes 724** 725** These integer constants are opcodes for the xFileControl method 726** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 727** interface. 728** 729** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 730** opcode causes the xFileControl method to write the current state of 731** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 732** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 733** into an integer that the pArg argument points to. This capability 734** is used during testing and only needs to be supported when SQLITE_TEST 735** is defined. 736** <ul> 737** <li>[[SQLITE_FCNTL_SIZE_HINT]] 738** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 739** layer a hint of how large the database file will grow to be during the 740** current transaction. This hint is not guaranteed to be accurate but it 741** is often close. The underlying VFS might choose to preallocate database 742** file space based on this hint in order to help writes to the database 743** file run faster. 744** 745** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 746** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 747** extends and truncates the database file in chunks of a size specified 748** by the user. The fourth argument to [sqlite3_file_control()] should 749** point to an integer (type int) containing the new chunk-size to use 750** for the nominated database. Allocating database file space in large 751** chunks (say 1MB at a time), may reduce file-system fragmentation and 752** improve performance on some systems. 753** 754** <li>[[SQLITE_FCNTL_FILE_POINTER]] 755** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 756** to the [sqlite3_file] object associated with a particular database 757** connection. See the [sqlite3_file_control()] documentation for 758** additional information. 759** 760** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 761** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by 762** SQLite and sent to all VFSes in place of a call to the xSync method 763** when the database connection has [PRAGMA synchronous] set to OFF.)^ 764** Some specialized VFSes need this signal in order to operate correctly 765** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 766** VFSes do not need this signal and should silently ignore this opcode. 767** Applications should not call [sqlite3_file_control()] with this 768** opcode as doing so may disrupt the operation of the specialized VFSes 769** that do require it. 770** 771** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 772** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 773** retry counts and intervals for certain disk I/O operations for the 774** windows [VFS] in order to provide robustness in the presence of 775** anti-virus programs. By default, the windows VFS will retry file read, 776** file write, and file delete operations up to 10 times, with a delay 777** of 25 milliseconds before the first retry and with the delay increasing 778** by an additional 25 milliseconds with each subsequent retry. This 779** opcode allows these two values (10 retries and 25 milliseconds of delay) 780** to be adjusted. The values are changed for all database connections 781** within the same process. The argument is a pointer to an array of two 782** integers where the first integer i the new retry count and the second 783** integer is the delay. If either integer is negative, then the setting 784** is not changed but instead the prior value of that setting is written 785** into the array entry, allowing the current retry settings to be 786** interrogated. The zDbName parameter is ignored. 787** 788** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 789** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 790** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 791** write ahead log and shared memory files used for transaction control 792** are automatically deleted when the latest connection to the database 793** closes. Setting persistent WAL mode causes those files to persist after 794** close. Persisting the files is useful when other processes that do not 795** have write permission on the directory containing the database file want 796** to read the database file, as the WAL and shared memory files must exist 797** in order for the database to be readable. The fourth parameter to 798** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 799** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 800** WAL mode. If the integer is -1, then it is overwritten with the current 801** WAL persistence setting. 802** 803** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 804** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 805** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 806** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 807** xDeviceCharacteristics methods. The fourth parameter to 808** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 809** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 810** mode. If the integer is -1, then it is overwritten with the current 811** zero-damage mode setting. 812** 813** <li>[[SQLITE_FCNTL_OVERWRITE]] 814** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 815** a write transaction to indicate that, unless it is rolled back for some 816** reason, the entire database file will be overwritten by the current 817** transaction. This is used by VACUUM operations. 818** 819** <li>[[SQLITE_FCNTL_VFSNAME]] 820** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 821** all [VFSes] in the VFS stack. The names are of all VFS shims and the 822** final bottom-level VFS are written into memory obtained from 823** [sqlite3_malloc()] and the result is stored in the char* variable 824** that the fourth parameter of [sqlite3_file_control()] points to. 825** The caller is responsible for freeing the memory when done. As with 826** all file-control actions, there is no guarantee that this will actually 827** do anything. Callers should initialize the char* variable to a NULL 828** pointer in case this file-control is not implemented. This file-control 829** is intended for diagnostic use only. 830** 831** <li>[[SQLITE_FCNTL_PRAGMA]] 832** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 833** file control is sent to the open [sqlite3_file] object corresponding 834** to the database file to which the pragma statement refers. ^The argument 835** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 836** pointers to strings (char**) in which the second element of the array 837** is the name of the pragma and the third element is the argument to the 838** pragma or NULL if the pragma has no argument. ^The handler for an 839** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 840** of the char** argument point to a string obtained from [sqlite3_mprintf()] 841** or the equivalent and that string will become the result of the pragma or 842** the error message if the pragma fails. ^If the 843** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 844** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 845** file control returns [SQLITE_OK], then the parser assumes that the 846** VFS has handled the PRAGMA itself and the parser generates a no-op 847** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns 848** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 849** that the VFS encountered an error while handling the [PRAGMA] and the 850** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 851** file control occurs at the beginning of pragma statement analysis and so 852** it is able to override built-in [PRAGMA] statements. 853** </ul> 854*/ 855#define SQLITE_FCNTL_LOCKSTATE 1 856#define SQLITE_GET_LOCKPROXYFILE 2 857#define SQLITE_SET_LOCKPROXYFILE 3 858#define SQLITE_LAST_ERRNO 4 859#define SQLITE_FCNTL_SIZE_HINT 5 860#define SQLITE_FCNTL_CHUNK_SIZE 6 861#define SQLITE_FCNTL_FILE_POINTER 7 862#define SQLITE_FCNTL_SYNC_OMITTED 8 863#define SQLITE_FCNTL_WIN32_AV_RETRY 9 864#define SQLITE_FCNTL_PERSIST_WAL 10 865#define SQLITE_FCNTL_OVERWRITE 11 866#define SQLITE_FCNTL_VFSNAME 12 867#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 868#define SQLITE_FCNTL_PRAGMA 14 869 870/* 871** CAPI3REF: Mutex Handle 872** 873** The mutex module within SQLite defines [sqlite3_mutex] to be an 874** abstract type for a mutex object. The SQLite core never looks 875** at the internal representation of an [sqlite3_mutex]. It only 876** deals with pointers to the [sqlite3_mutex] object. 877** 878** Mutexes are created using [sqlite3_mutex_alloc()]. 879*/ 880typedef struct sqlite3_mutex sqlite3_mutex; 881 882/* 883** CAPI3REF: OS Interface Object 884** 885** An instance of the sqlite3_vfs object defines the interface between 886** the SQLite core and the underlying operating system. The "vfs" 887** in the name of the object stands for "virtual file system". See 888** the [VFS | VFS documentation] for further information. 889** 890** The value of the iVersion field is initially 1 but may be larger in 891** future versions of SQLite. Additional fields may be appended to this 892** object when the iVersion value is increased. Note that the structure 893** of the sqlite3_vfs object changes in the transaction between 894** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 895** modified. 896** 897** The szOsFile field is the size of the subclassed [sqlite3_file] 898** structure used by this VFS. mxPathname is the maximum length of 899** a pathname in this VFS. 900** 901** Registered sqlite3_vfs objects are kept on a linked list formed by 902** the pNext pointer. The [sqlite3_vfs_register()] 903** and [sqlite3_vfs_unregister()] interfaces manage this list 904** in a thread-safe way. The [sqlite3_vfs_find()] interface 905** searches the list. Neither the application code nor the VFS 906** implementation should use the pNext pointer. 907** 908** The pNext field is the only field in the sqlite3_vfs 909** structure that SQLite will ever modify. SQLite will only access 910** or modify this field while holding a particular static mutex. 911** The application should never modify anything within the sqlite3_vfs 912** object once the object has been registered. 913** 914** The zName field holds the name of the VFS module. The name must 915** be unique across all VFS modules. 916** 917** [[sqlite3_vfs.xOpen]] 918** ^SQLite guarantees that the zFilename parameter to xOpen 919** is either a NULL pointer or string obtained 920** from xFullPathname() with an optional suffix added. 921** ^If a suffix is added to the zFilename parameter, it will 922** consist of a single "-" character followed by no more than 923** 11 alphanumeric and/or "-" characters. 924** ^SQLite further guarantees that 925** the string will be valid and unchanged until xClose() is 926** called. Because of the previous sentence, 927** the [sqlite3_file] can safely store a pointer to the 928** filename if it needs to remember the filename for some reason. 929** If the zFilename parameter to xOpen is a NULL pointer then xOpen 930** must invent its own temporary name for the file. ^Whenever the 931** xFilename parameter is NULL it will also be the case that the 932** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 933** 934** The flags argument to xOpen() includes all bits set in 935** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 936** or [sqlite3_open16()] is used, then flags includes at least 937** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 938** If xOpen() opens a file read-only then it sets *pOutFlags to 939** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 940** 941** ^(SQLite will also add one of the following flags to the xOpen() 942** call, depending on the object being opened: 943** 944** <ul> 945** <li> [SQLITE_OPEN_MAIN_DB] 946** <li> [SQLITE_OPEN_MAIN_JOURNAL] 947** <li> [SQLITE_OPEN_TEMP_DB] 948** <li> [SQLITE_OPEN_TEMP_JOURNAL] 949** <li> [SQLITE_OPEN_TRANSIENT_DB] 950** <li> [SQLITE_OPEN_SUBJOURNAL] 951** <li> [SQLITE_OPEN_MASTER_JOURNAL] 952** <li> [SQLITE_OPEN_WAL] 953** </ul>)^ 954** 955** The file I/O implementation can use the object type flags to 956** change the way it deals with files. For example, an application 957** that does not care about crash recovery or rollback might make 958** the open of a journal file a no-op. Writes to this journal would 959** also be no-ops, and any attempt to read the journal would return 960** SQLITE_IOERR. Or the implementation might recognize that a database 961** file will be doing page-aligned sector reads and writes in a random 962** order and set up its I/O subsystem accordingly. 963** 964** SQLite might also add one of the following flags to the xOpen method: 965** 966** <ul> 967** <li> [SQLITE_OPEN_DELETEONCLOSE] 968** <li> [SQLITE_OPEN_EXCLUSIVE] 969** </ul> 970** 971** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 972** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 973** will be set for TEMP databases and their journals, transient 974** databases, and subjournals. 975** 976** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 977** with the [SQLITE_OPEN_CREATE] flag, which are both directly 978** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 979** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 980** SQLITE_OPEN_CREATE, is used to indicate that file should always 981** be created, and that it is an error if it already exists. 982** It is <i>not</i> used to indicate the file should be opened 983** for exclusive access. 984** 985** ^At least szOsFile bytes of memory are allocated by SQLite 986** to hold the [sqlite3_file] structure passed as the third 987** argument to xOpen. The xOpen method does not have to 988** allocate the structure; it should just fill it in. Note that 989** the xOpen method must set the sqlite3_file.pMethods to either 990** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 991** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 992** element will be valid after xOpen returns regardless of the success 993** or failure of the xOpen call. 994** 995** [[sqlite3_vfs.xAccess]] 996** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 997** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 998** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 999** to test whether a file is at least readable. The file can be a 1000** directory. 1001** 1002** ^SQLite will always allocate at least mxPathname+1 bytes for the 1003** output buffer xFullPathname. The exact size of the output buffer 1004** is also passed as a parameter to both methods. If the output buffer 1005** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1006** handled as a fatal error by SQLite, vfs implementations should endeavor 1007** to prevent this by setting mxPathname to a sufficiently large value. 1008** 1009** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1010** interfaces are not strictly a part of the filesystem, but they are 1011** included in the VFS structure for completeness. 1012** The xRandomness() function attempts to return nBytes bytes 1013** of good-quality randomness into zOut. The return value is 1014** the actual number of bytes of randomness obtained. 1015** The xSleep() method causes the calling thread to sleep for at 1016** least the number of microseconds given. ^The xCurrentTime() 1017** method returns a Julian Day Number for the current date and time as 1018** a floating point value. 1019** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1020** Day Number multiplied by 86400000 (the number of milliseconds in 1021** a 24-hour day). 1022** ^SQLite will use the xCurrentTimeInt64() method to get the current 1023** date and time if that method is available (if iVersion is 2 or 1024** greater and the function pointer is not NULL) and will fall back 1025** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1026** 1027** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1028** are not used by the SQLite core. These optional interfaces are provided 1029** by some VFSes to facilitate testing of the VFS code. By overriding 1030** system calls with functions under its control, a test program can 1031** simulate faults and error conditions that would otherwise be difficult 1032** or impossible to induce. The set of system calls that can be overridden 1033** varies from one VFS to another, and from one version of the same VFS to the 1034** next. Applications that use these interfaces must be prepared for any 1035** or all of these interfaces to be NULL or for their behavior to change 1036** from one release to the next. Applications must not attempt to access 1037** any of these methods if the iVersion of the VFS is less than 3. 1038*/ 1039typedef struct sqlite3_vfs sqlite3_vfs; 1040typedef void (*sqlite3_syscall_ptr)(void); 1041struct sqlite3_vfs { 1042 int iVersion; /* Structure version number (currently 3) */ 1043 int szOsFile; /* Size of subclassed sqlite3_file */ 1044 int mxPathname; /* Maximum file pathname length */ 1045 sqlite3_vfs *pNext; /* Next registered VFS */ 1046 const char *zName; /* Name of this virtual file system */ 1047 void *pAppData; /* Pointer to application-specific data */ 1048 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1049 int flags, int *pOutFlags); 1050 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1051 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1052 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1053 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1054 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1055 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1056 void (*xDlClose)(sqlite3_vfs*, void*); 1057 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1058 int (*xSleep)(sqlite3_vfs*, int microseconds); 1059 int (*xCurrentTime)(sqlite3_vfs*, double*); 1060 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1061 /* 1062 ** The methods above are in version 1 of the sqlite_vfs object 1063 ** definition. Those that follow are added in version 2 or later 1064 */ 1065 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1066 /* 1067 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1068 ** Those below are for version 3 and greater. 1069 */ 1070 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1071 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1072 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1073 /* 1074 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1075 ** New fields may be appended in figure versions. The iVersion 1076 ** value will increment whenever this happens. 1077 */ 1078}; 1079 1080/* 1081** CAPI3REF: Flags for the xAccess VFS method 1082** 1083** These integer constants can be used as the third parameter to 1084** the xAccess method of an [sqlite3_vfs] object. They determine 1085** what kind of permissions the xAccess method is looking for. 1086** With SQLITE_ACCESS_EXISTS, the xAccess method 1087** simply checks whether the file exists. 1088** With SQLITE_ACCESS_READWRITE, the xAccess method 1089** checks whether the named directory is both readable and writable 1090** (in other words, if files can be added, removed, and renamed within 1091** the directory). 1092** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1093** [temp_store_directory pragma], though this could change in a future 1094** release of SQLite. 1095** With SQLITE_ACCESS_READ, the xAccess method 1096** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1097** currently unused, though it might be used in a future release of 1098** SQLite. 1099*/ 1100#define SQLITE_ACCESS_EXISTS 0 1101#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1102#define SQLITE_ACCESS_READ 2 /* Unused */ 1103 1104/* 1105** CAPI3REF: Flags for the xShmLock VFS method 1106** 1107** These integer constants define the various locking operations 1108** allowed by the xShmLock method of [sqlite3_io_methods]. The 1109** following are the only legal combinations of flags to the 1110** xShmLock method: 1111** 1112** <ul> 1113** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1114** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1115** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1116** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1117** </ul> 1118** 1119** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1120** was given no the corresponding lock. 1121** 1122** The xShmLock method can transition between unlocked and SHARED or 1123** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1124** and EXCLUSIVE. 1125*/ 1126#define SQLITE_SHM_UNLOCK 1 1127#define SQLITE_SHM_LOCK 2 1128#define SQLITE_SHM_SHARED 4 1129#define SQLITE_SHM_EXCLUSIVE 8 1130 1131/* 1132** CAPI3REF: Maximum xShmLock index 1133** 1134** The xShmLock method on [sqlite3_io_methods] may use values 1135** between 0 and this upper bound as its "offset" argument. 1136** The SQLite core will never attempt to acquire or release a 1137** lock outside of this range 1138*/ 1139#define SQLITE_SHM_NLOCK 8 1140 1141 1142/* 1143** CAPI3REF: Initialize The SQLite Library 1144** 1145** ^The sqlite3_initialize() routine initializes the 1146** SQLite library. ^The sqlite3_shutdown() routine 1147** deallocates any resources that were allocated by sqlite3_initialize(). 1148** These routines are designed to aid in process initialization and 1149** shutdown on embedded systems. Workstation applications using 1150** SQLite normally do not need to invoke either of these routines. 1151** 1152** A call to sqlite3_initialize() is an "effective" call if it is 1153** the first time sqlite3_initialize() is invoked during the lifetime of 1154** the process, or if it is the first time sqlite3_initialize() is invoked 1155** following a call to sqlite3_shutdown(). ^(Only an effective call 1156** of sqlite3_initialize() does any initialization. All other calls 1157** are harmless no-ops.)^ 1158** 1159** A call to sqlite3_shutdown() is an "effective" call if it is the first 1160** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1161** an effective call to sqlite3_shutdown() does any deinitialization. 1162** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1163** 1164** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1165** is not. The sqlite3_shutdown() interface must only be called from a 1166** single thread. All open [database connections] must be closed and all 1167** other SQLite resources must be deallocated prior to invoking 1168** sqlite3_shutdown(). 1169** 1170** Among other things, ^sqlite3_initialize() will invoke 1171** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1172** will invoke sqlite3_os_end(). 1173** 1174** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1175** ^If for some reason, sqlite3_initialize() is unable to initialize 1176** the library (perhaps it is unable to allocate a needed resource such 1177** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1178** 1179** ^The sqlite3_initialize() routine is called internally by many other 1180** SQLite interfaces so that an application usually does not need to 1181** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1182** calls sqlite3_initialize() so the SQLite library will be automatically 1183** initialized when [sqlite3_open()] is called if it has not be initialized 1184** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1185** compile-time option, then the automatic calls to sqlite3_initialize() 1186** are omitted and the application must call sqlite3_initialize() directly 1187** prior to using any other SQLite interface. For maximum portability, 1188** it is recommended that applications always invoke sqlite3_initialize() 1189** directly prior to using any other SQLite interface. Future releases 1190** of SQLite may require this. In other words, the behavior exhibited 1191** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1192** default behavior in some future release of SQLite. 1193** 1194** The sqlite3_os_init() routine does operating-system specific 1195** initialization of the SQLite library. The sqlite3_os_end() 1196** routine undoes the effect of sqlite3_os_init(). Typical tasks 1197** performed by these routines include allocation or deallocation 1198** of static resources, initialization of global variables, 1199** setting up a default [sqlite3_vfs] module, or setting up 1200** a default configuration using [sqlite3_config()]. 1201** 1202** The application should never invoke either sqlite3_os_init() 1203** or sqlite3_os_end() directly. The application should only invoke 1204** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1205** interface is called automatically by sqlite3_initialize() and 1206** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1207** implementations for sqlite3_os_init() and sqlite3_os_end() 1208** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1209** When [custom builds | built for other platforms] 1210** (using the [SQLITE_OS_OTHER=1] compile-time 1211** option) the application must supply a suitable implementation for 1212** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1213** implementation of sqlite3_os_init() or sqlite3_os_end() 1214** must return [SQLITE_OK] on success and some other [error code] upon 1215** failure. 1216*/ 1217int sqlite3_initialize(void); 1218int sqlite3_shutdown(void); 1219int sqlite3_os_init(void); 1220int sqlite3_os_end(void); 1221 1222/* 1223** CAPI3REF: Configuring The SQLite Library 1224** 1225** The sqlite3_config() interface is used to make global configuration 1226** changes to SQLite in order to tune SQLite to the specific needs of 1227** the application. The default configuration is recommended for most 1228** applications and so this routine is usually not necessary. It is 1229** provided to support rare applications with unusual needs. 1230** 1231** The sqlite3_config() interface is not threadsafe. The application 1232** must insure that no other SQLite interfaces are invoked by other 1233** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1234** may only be invoked prior to library initialization using 1235** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1236** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1237** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1238** Note, however, that ^sqlite3_config() can be called as part of the 1239** implementation of an application-defined [sqlite3_os_init()]. 1240** 1241** The first argument to sqlite3_config() is an integer 1242** [configuration option] that determines 1243** what property of SQLite is to be configured. Subsequent arguments 1244** vary depending on the [configuration option] 1245** in the first argument. 1246** 1247** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1248** ^If the option is unknown or SQLite is unable to set the option 1249** then this routine returns a non-zero [error code]. 1250*/ 1251int sqlite3_config(int, ...); 1252 1253/* 1254** CAPI3REF: Configure database connections 1255** 1256** The sqlite3_db_config() interface is used to make configuration 1257** changes to a [database connection]. The interface is similar to 1258** [sqlite3_config()] except that the changes apply to a single 1259** [database connection] (specified in the first argument). 1260** 1261** The second argument to sqlite3_db_config(D,V,...) is the 1262** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1263** that indicates what aspect of the [database connection] is being configured. 1264** Subsequent arguments vary depending on the configuration verb. 1265** 1266** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1267** the call is considered successful. 1268*/ 1269int sqlite3_db_config(sqlite3*, int op, ...); 1270 1271/* 1272** CAPI3REF: Memory Allocation Routines 1273** 1274** An instance of this object defines the interface between SQLite 1275** and low-level memory allocation routines. 1276** 1277** This object is used in only one place in the SQLite interface. 1278** A pointer to an instance of this object is the argument to 1279** [sqlite3_config()] when the configuration option is 1280** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1281** By creating an instance of this object 1282** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1283** during configuration, an application can specify an alternative 1284** memory allocation subsystem for SQLite to use for all of its 1285** dynamic memory needs. 1286** 1287** Note that SQLite comes with several [built-in memory allocators] 1288** that are perfectly adequate for the overwhelming majority of applications 1289** and that this object is only useful to a tiny minority of applications 1290** with specialized memory allocation requirements. This object is 1291** also used during testing of SQLite in order to specify an alternative 1292** memory allocator that simulates memory out-of-memory conditions in 1293** order to verify that SQLite recovers gracefully from such 1294** conditions. 1295** 1296** The xMalloc, xRealloc, and xFree methods must work like the 1297** malloc(), realloc() and free() functions from the standard C library. 1298** ^SQLite guarantees that the second argument to 1299** xRealloc is always a value returned by a prior call to xRoundup. 1300** 1301** xSize should return the allocated size of a memory allocation 1302** previously obtained from xMalloc or xRealloc. The allocated size 1303** is always at least as big as the requested size but may be larger. 1304** 1305** The xRoundup method returns what would be the allocated size of 1306** a memory allocation given a particular requested size. Most memory 1307** allocators round up memory allocations at least to the next multiple 1308** of 8. Some allocators round up to a larger multiple or to a power of 2. 1309** Every memory allocation request coming in through [sqlite3_malloc()] 1310** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1311** that causes the corresponding memory allocation to fail. 1312** 1313** The xInit method initializes the memory allocator. (For example, 1314** it might allocate any require mutexes or initialize internal data 1315** structures. The xShutdown method is invoked (indirectly) by 1316** [sqlite3_shutdown()] and should deallocate any resources acquired 1317** by xInit. The pAppData pointer is used as the only parameter to 1318** xInit and xShutdown. 1319** 1320** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1321** the xInit method, so the xInit method need not be threadsafe. The 1322** xShutdown method is only called from [sqlite3_shutdown()] so it does 1323** not need to be threadsafe either. For all other methods, SQLite 1324** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1325** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1326** it is by default) and so the methods are automatically serialized. 1327** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1328** methods must be threadsafe or else make their own arrangements for 1329** serialization. 1330** 1331** SQLite will never invoke xInit() more than once without an intervening 1332** call to xShutdown(). 1333*/ 1334typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1335struct sqlite3_mem_methods { 1336 void *(*xMalloc)(int); /* Memory allocation function */ 1337 void (*xFree)(void*); /* Free a prior allocation */ 1338 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1339 int (*xSize)(void*); /* Return the size of an allocation */ 1340 int (*xRoundup)(int); /* Round up request size to allocation size */ 1341 int (*xInit)(void*); /* Initialize the memory allocator */ 1342 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1343 void *pAppData; /* Argument to xInit() and xShutdown() */ 1344}; 1345 1346/* 1347** CAPI3REF: Configuration Options 1348** KEYWORDS: {configuration option} 1349** 1350** These constants are the available integer configuration options that 1351** can be passed as the first argument to the [sqlite3_config()] interface. 1352** 1353** New configuration options may be added in future releases of SQLite. 1354** Existing configuration options might be discontinued. Applications 1355** should check the return code from [sqlite3_config()] to make sure that 1356** the call worked. The [sqlite3_config()] interface will return a 1357** non-zero [error code] if a discontinued or unsupported configuration option 1358** is invoked. 1359** 1360** <dl> 1361** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1362** <dd>There are no arguments to this option. ^This option sets the 1363** [threading mode] to Single-thread. In other words, it disables 1364** all mutexing and puts SQLite into a mode where it can only be used 1365** by a single thread. ^If SQLite is compiled with 1366** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1367** it is not possible to change the [threading mode] from its default 1368** value of Single-thread and so [sqlite3_config()] will return 1369** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1370** configuration option.</dd> 1371** 1372** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1373** <dd>There are no arguments to this option. ^This option sets the 1374** [threading mode] to Multi-thread. In other words, it disables 1375** mutexing on [database connection] and [prepared statement] objects. 1376** The application is responsible for serializing access to 1377** [database connections] and [prepared statements]. But other mutexes 1378** are enabled so that SQLite will be safe to use in a multi-threaded 1379** environment as long as no two threads attempt to use the same 1380** [database connection] at the same time. ^If SQLite is compiled with 1381** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1382** it is not possible to set the Multi-thread [threading mode] and 1383** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1384** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1385** 1386** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1387** <dd>There are no arguments to this option. ^This option sets the 1388** [threading mode] to Serialized. In other words, this option enables 1389** all mutexes including the recursive 1390** mutexes on [database connection] and [prepared statement] objects. 1391** In this mode (which is the default when SQLite is compiled with 1392** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1393** to [database connections] and [prepared statements] so that the 1394** application is free to use the same [database connection] or the 1395** same [prepared statement] in different threads at the same time. 1396** ^If SQLite is compiled with 1397** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1398** it is not possible to set the Serialized [threading mode] and 1399** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1400** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1401** 1402** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1403** <dd> ^(This option takes a single argument which is a pointer to an 1404** instance of the [sqlite3_mem_methods] structure. The argument specifies 1405** alternative low-level memory allocation routines to be used in place of 1406** the memory allocation routines built into SQLite.)^ ^SQLite makes 1407** its own private copy of the content of the [sqlite3_mem_methods] structure 1408** before the [sqlite3_config()] call returns.</dd> 1409** 1410** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1411** <dd> ^(This option takes a single argument which is a pointer to an 1412** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1413** structure is filled with the currently defined memory allocation routines.)^ 1414** This option can be used to overload the default memory allocation 1415** routines with a wrapper that simulations memory allocation failure or 1416** tracks memory usage, for example. </dd> 1417** 1418** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1419** <dd> ^This option takes single argument of type int, interpreted as a 1420** boolean, which enables or disables the collection of memory allocation 1421** statistics. ^(When memory allocation statistics are disabled, the 1422** following SQLite interfaces become non-operational: 1423** <ul> 1424** <li> [sqlite3_memory_used()] 1425** <li> [sqlite3_memory_highwater()] 1426** <li> [sqlite3_soft_heap_limit64()] 1427** <li> [sqlite3_status()] 1428** </ul>)^ 1429** ^Memory allocation statistics are enabled by default unless SQLite is 1430** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1431** allocation statistics are disabled by default. 1432** </dd> 1433** 1434** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1435** <dd> ^This option specifies a static memory buffer that SQLite can use for 1436** scratch memory. There are three arguments: A pointer an 8-byte 1437** aligned memory buffer from which the scratch allocations will be 1438** drawn, the size of each scratch allocation (sz), 1439** and the maximum number of scratch allocations (N). The sz 1440** argument must be a multiple of 16. 1441** The first argument must be a pointer to an 8-byte aligned buffer 1442** of at least sz*N bytes of memory. 1443** ^SQLite will use no more than two scratch buffers per thread. So 1444** N should be set to twice the expected maximum number of threads. 1445** ^SQLite will never require a scratch buffer that is more than 6 1446** times the database page size. ^If SQLite needs needs additional 1447** scratch memory beyond what is provided by this configuration option, then 1448** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1449** 1450** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1451** <dd> ^This option specifies a static memory buffer that SQLite can use for 1452** the database page cache with the default page cache implementation. 1453** This configuration should not be used if an application-define page 1454** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1455** There are three arguments to this option: A pointer to 8-byte aligned 1456** memory, the size of each page buffer (sz), and the number of pages (N). 1457** The sz argument should be the size of the largest database page 1458** (a power of two between 512 and 32768) plus a little extra for each 1459** page header. ^The page header size is 20 to 40 bytes depending on 1460** the host architecture. ^It is harmless, apart from the wasted memory, 1461** to make sz a little too large. The first 1462** argument should point to an allocation of at least sz*N bytes of memory. 1463** ^SQLite will use the memory provided by the first argument to satisfy its 1464** memory needs for the first N pages that it adds to cache. ^If additional 1465** page cache memory is needed beyond what is provided by this option, then 1466** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1467** The pointer in the first argument must 1468** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1469** will be undefined.</dd> 1470** 1471** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1472** <dd> ^This option specifies a static memory buffer that SQLite will use 1473** for all of its dynamic memory allocation needs beyond those provided 1474** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1475** There are three arguments: An 8-byte aligned pointer to the memory, 1476** the number of bytes in the memory buffer, and the minimum allocation size. 1477** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1478** to using its default memory allocator (the system malloc() implementation), 1479** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1480** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1481** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1482** allocator is engaged to handle all of SQLites memory allocation needs. 1483** The first pointer (the memory pointer) must be aligned to an 8-byte 1484** boundary or subsequent behavior of SQLite will be undefined. 1485** The minimum allocation size is capped at 2**12. Reasonable values 1486** for the minimum allocation size are 2**5 through 2**8.</dd> 1487** 1488** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1489** <dd> ^(This option takes a single argument which is a pointer to an 1490** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1491** alternative low-level mutex routines to be used in place 1492** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1493** content of the [sqlite3_mutex_methods] structure before the call to 1494** [sqlite3_config()] returns. ^If SQLite is compiled with 1495** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1496** the entire mutexing subsystem is omitted from the build and hence calls to 1497** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1498** return [SQLITE_ERROR].</dd> 1499** 1500** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1501** <dd> ^(This option takes a single argument which is a pointer to an 1502** instance of the [sqlite3_mutex_methods] structure. The 1503** [sqlite3_mutex_methods] 1504** structure is filled with the currently defined mutex routines.)^ 1505** This option can be used to overload the default mutex allocation 1506** routines with a wrapper used to track mutex usage for performance 1507** profiling or testing, for example. ^If SQLite is compiled with 1508** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1509** the entire mutexing subsystem is omitted from the build and hence calls to 1510** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1511** return [SQLITE_ERROR].</dd> 1512** 1513** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1514** <dd> ^(This option takes two arguments that determine the default 1515** memory allocation for the lookaside memory allocator on each 1516** [database connection]. The first argument is the 1517** size of each lookaside buffer slot and the second is the number of 1518** slots allocated to each database connection.)^ ^(This option sets the 1519** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1520** verb to [sqlite3_db_config()] can be used to change the lookaside 1521** configuration on individual connections.)^ </dd> 1522** 1523** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1524** <dd> ^(This option takes a single argument which is a pointer to 1525** an [sqlite3_pcache_methods2] object. This object specifies the interface 1526** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1527** object and uses it for page cache memory allocations.</dd> 1528** 1529** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1530** <dd> ^(This option takes a single argument which is a pointer to an 1531** [sqlite3_pcache_methods2] object. SQLite copies of the current 1532** page cache implementation into that object.)^ </dd> 1533** 1534** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1535** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1536** function with a call signature of void(*)(void*,int,const char*), 1537** and a pointer to void. ^If the function pointer is not NULL, it is 1538** invoked by [sqlite3_log()] to process each logging event. ^If the 1539** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1540** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1541** passed through as the first parameter to the application-defined logger 1542** function whenever that function is invoked. ^The second parameter to 1543** the logger function is a copy of the first parameter to the corresponding 1544** [sqlite3_log()] call and is intended to be a [result code] or an 1545** [extended result code]. ^The third parameter passed to the logger is 1546** log message after formatting via [sqlite3_snprintf()]. 1547** The SQLite logging interface is not reentrant; the logger function 1548** supplied by the application must not invoke any SQLite interface. 1549** In a multi-threaded application, the application-defined logger 1550** function must be threadsafe. </dd> 1551** 1552** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1553** <dd> This option takes a single argument of type int. If non-zero, then 1554** URI handling is globally enabled. If the parameter is zero, then URI handling 1555** is globally disabled. If URI handling is globally enabled, all filenames 1556** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1557** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1558** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1559** connection is opened. If it is globally disabled, filenames are 1560** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1561** database connection is opened. By default, URI handling is globally 1562** disabled. The default value may be changed by compiling with the 1563** [SQLITE_USE_URI] symbol defined. 1564** 1565** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1566** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1567** <dd> These options are obsolete and should not be used by new code. 1568** They are retained for backwards compatibility but are now no-ops. 1569** </dl> 1570*/ 1571#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1572#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1573#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1574#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1575#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1576#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1577#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1578#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1579#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1580#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1581#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1582/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1583#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1584#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1585#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1586#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1587#define SQLITE_CONFIG_URI 17 /* int */ 1588#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1589#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1590 1591/* 1592** CAPI3REF: Database Connection Configuration Options 1593** 1594** These constants are the available integer configuration options that 1595** can be passed as the second argument to the [sqlite3_db_config()] interface. 1596** 1597** New configuration options may be added in future releases of SQLite. 1598** Existing configuration options might be discontinued. Applications 1599** should check the return code from [sqlite3_db_config()] to make sure that 1600** the call worked. ^The [sqlite3_db_config()] interface will return a 1601** non-zero [error code] if a discontinued or unsupported configuration option 1602** is invoked. 1603** 1604** <dl> 1605** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1606** <dd> ^This option takes three additional arguments that determine the 1607** [lookaside memory allocator] configuration for the [database connection]. 1608** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1609** pointer to a memory buffer to use for lookaside memory. 1610** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1611** may be NULL in which case SQLite will allocate the 1612** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1613** size of each lookaside buffer slot. ^The third argument is the number of 1614** slots. The size of the buffer in the first argument must be greater than 1615** or equal to the product of the second and third arguments. The buffer 1616** must be aligned to an 8-byte boundary. ^If the second argument to 1617** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1618** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1619** configuration for a database connection can only be changed when that 1620** connection is not currently using lookaside memory, or in other words 1621** when the "current value" returned by 1622** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1623** Any attempt to change the lookaside memory configuration when lookaside 1624** memory is in use leaves the configuration unchanged and returns 1625** [SQLITE_BUSY].)^</dd> 1626** 1627** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1628** <dd> ^This option is used to enable or disable the enforcement of 1629** [foreign key constraints]. There should be two additional arguments. 1630** The first argument is an integer which is 0 to disable FK enforcement, 1631** positive to enable FK enforcement or negative to leave FK enforcement 1632** unchanged. The second parameter is a pointer to an integer into which 1633** is written 0 or 1 to indicate whether FK enforcement is off or on 1634** following this call. The second parameter may be a NULL pointer, in 1635** which case the FK enforcement setting is not reported back. </dd> 1636** 1637** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1638** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1639** There should be two additional arguments. 1640** The first argument is an integer which is 0 to disable triggers, 1641** positive to enable triggers or negative to leave the setting unchanged. 1642** The second parameter is a pointer to an integer into which 1643** is written 0 or 1 to indicate whether triggers are disabled or enabled 1644** following this call. The second parameter may be a NULL pointer, in 1645** which case the trigger setting is not reported back. </dd> 1646** 1647** </dl> 1648*/ 1649#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1650#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1651#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1652 1653 1654/* 1655** CAPI3REF: Enable Or Disable Extended Result Codes 1656** 1657** ^The sqlite3_extended_result_codes() routine enables or disables the 1658** [extended result codes] feature of SQLite. ^The extended result 1659** codes are disabled by default for historical compatibility. 1660*/ 1661int sqlite3_extended_result_codes(sqlite3*, int onoff); 1662 1663/* 1664** CAPI3REF: Last Insert Rowid 1665** 1666** ^Each entry in an SQLite table has a unique 64-bit signed 1667** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1668** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1669** names are not also used by explicitly declared columns. ^If 1670** the table has a column of type [INTEGER PRIMARY KEY] then that column 1671** is another alias for the rowid. 1672** 1673** ^This routine returns the [rowid] of the most recent 1674** successful [INSERT] into the database from the [database connection] 1675** in the first argument. ^As of SQLite version 3.7.7, this routines 1676** records the last insert rowid of both ordinary tables and [virtual tables]. 1677** ^If no successful [INSERT]s 1678** have ever occurred on that database connection, zero is returned. 1679** 1680** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1681** method, then this routine will return the [rowid] of the inserted 1682** row as long as the trigger or virtual table method is running. 1683** But once the trigger or virtual table method ends, the value returned 1684** by this routine reverts to what it was before the trigger or virtual 1685** table method began.)^ 1686** 1687** ^An [INSERT] that fails due to a constraint violation is not a 1688** successful [INSERT] and does not change the value returned by this 1689** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1690** and INSERT OR ABORT make no changes to the return value of this 1691** routine when their insertion fails. ^(When INSERT OR REPLACE 1692** encounters a constraint violation, it does not fail. The 1693** INSERT continues to completion after deleting rows that caused 1694** the constraint problem so INSERT OR REPLACE will always change 1695** the return value of this interface.)^ 1696** 1697** ^For the purposes of this routine, an [INSERT] is considered to 1698** be successful even if it is subsequently rolled back. 1699** 1700** This function is accessible to SQL statements via the 1701** [last_insert_rowid() SQL function]. 1702** 1703** If a separate thread performs a new [INSERT] on the same 1704** database connection while the [sqlite3_last_insert_rowid()] 1705** function is running and thus changes the last insert [rowid], 1706** then the value returned by [sqlite3_last_insert_rowid()] is 1707** unpredictable and might not equal either the old or the new 1708** last insert [rowid]. 1709*/ 1710sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1711 1712/* 1713** CAPI3REF: Count The Number Of Rows Modified 1714** 1715** ^This function returns the number of database rows that were changed 1716** or inserted or deleted by the most recently completed SQL statement 1717** on the [database connection] specified by the first parameter. 1718** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1719** or [DELETE] statement are counted. Auxiliary changes caused by 1720** triggers or [foreign key actions] are not counted.)^ Use the 1721** [sqlite3_total_changes()] function to find the total number of changes 1722** including changes caused by triggers and foreign key actions. 1723** 1724** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1725** are not counted. Only real table changes are counted. 1726** 1727** ^(A "row change" is a change to a single row of a single table 1728** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1729** are changed as side effects of [REPLACE] constraint resolution, 1730** rollback, ABORT processing, [DROP TABLE], or by any other 1731** mechanisms do not count as direct row changes.)^ 1732** 1733** A "trigger context" is a scope of execution that begins and 1734** ends with the script of a [CREATE TRIGGER | trigger]. 1735** Most SQL statements are 1736** evaluated outside of any trigger. This is the "top level" 1737** trigger context. If a trigger fires from the top level, a 1738** new trigger context is entered for the duration of that one 1739** trigger. Subtriggers create subcontexts for their duration. 1740** 1741** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1742** not create a new trigger context. 1743** 1744** ^This function returns the number of direct row changes in the 1745** most recent INSERT, UPDATE, or DELETE statement within the same 1746** trigger context. 1747** 1748** ^Thus, when called from the top level, this function returns the 1749** number of changes in the most recent INSERT, UPDATE, or DELETE 1750** that also occurred at the top level. ^(Within the body of a trigger, 1751** the sqlite3_changes() interface can be called to find the number of 1752** changes in the most recently completed INSERT, UPDATE, or DELETE 1753** statement within the body of the same trigger. 1754** However, the number returned does not include changes 1755** caused by subtriggers since those have their own context.)^ 1756** 1757** See also the [sqlite3_total_changes()] interface, the 1758** [count_changes pragma], and the [changes() SQL function]. 1759** 1760** If a separate thread makes changes on the same database connection 1761** while [sqlite3_changes()] is running then the value returned 1762** is unpredictable and not meaningful. 1763*/ 1764int sqlite3_changes(sqlite3*); 1765 1766/* 1767** CAPI3REF: Total Number Of Rows Modified 1768** 1769** ^This function returns the number of row changes caused by [INSERT], 1770** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1771** ^(The count returned by sqlite3_total_changes() includes all changes 1772** from all [CREATE TRIGGER | trigger] contexts and changes made by 1773** [foreign key actions]. However, 1774** the count does not include changes used to implement [REPLACE] constraints, 1775** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1776** count does not include rows of views that fire an [INSTEAD OF trigger], 1777** though if the INSTEAD OF trigger makes changes of its own, those changes 1778** are counted.)^ 1779** ^The sqlite3_total_changes() function counts the changes as soon as 1780** the statement that makes them is completed (when the statement handle 1781** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1782** 1783** See also the [sqlite3_changes()] interface, the 1784** [count_changes pragma], and the [total_changes() SQL function]. 1785** 1786** If a separate thread makes changes on the same database connection 1787** while [sqlite3_total_changes()] is running then the value 1788** returned is unpredictable and not meaningful. 1789*/ 1790int sqlite3_total_changes(sqlite3*); 1791 1792/* 1793** CAPI3REF: Interrupt A Long-Running Query 1794** 1795** ^This function causes any pending database operation to abort and 1796** return at its earliest opportunity. This routine is typically 1797** called in response to a user action such as pressing "Cancel" 1798** or Ctrl-C where the user wants a long query operation to halt 1799** immediately. 1800** 1801** ^It is safe to call this routine from a thread different from the 1802** thread that is currently running the database operation. But it 1803** is not safe to call this routine with a [database connection] that 1804** is closed or might close before sqlite3_interrupt() returns. 1805** 1806** ^If an SQL operation is very nearly finished at the time when 1807** sqlite3_interrupt() is called, then it might not have an opportunity 1808** to be interrupted and might continue to completion. 1809** 1810** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1811** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1812** that is inside an explicit transaction, then the entire transaction 1813** will be rolled back automatically. 1814** 1815** ^The sqlite3_interrupt(D) call is in effect until all currently running 1816** SQL statements on [database connection] D complete. ^Any new SQL statements 1817** that are started after the sqlite3_interrupt() call and before the 1818** running statements reaches zero are interrupted as if they had been 1819** running prior to the sqlite3_interrupt() call. ^New SQL statements 1820** that are started after the running statement count reaches zero are 1821** not effected by the sqlite3_interrupt(). 1822** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1823** SQL statements is a no-op and has no effect on SQL statements 1824** that are started after the sqlite3_interrupt() call returns. 1825** 1826** If the database connection closes while [sqlite3_interrupt()] 1827** is running then bad things will likely happen. 1828*/ 1829void sqlite3_interrupt(sqlite3*); 1830 1831/* 1832** CAPI3REF: Determine If An SQL Statement Is Complete 1833** 1834** These routines are useful during command-line input to determine if the 1835** currently entered text seems to form a complete SQL statement or 1836** if additional input is needed before sending the text into 1837** SQLite for parsing. ^These routines return 1 if the input string 1838** appears to be a complete SQL statement. ^A statement is judged to be 1839** complete if it ends with a semicolon token and is not a prefix of a 1840** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1841** string literals or quoted identifier names or comments are not 1842** independent tokens (they are part of the token in which they are 1843** embedded) and thus do not count as a statement terminator. ^Whitespace 1844** and comments that follow the final semicolon are ignored. 1845** 1846** ^These routines return 0 if the statement is incomplete. ^If a 1847** memory allocation fails, then SQLITE_NOMEM is returned. 1848** 1849** ^These routines do not parse the SQL statements thus 1850** will not detect syntactically incorrect SQL. 1851** 1852** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 1853** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 1854** automatically by sqlite3_complete16(). If that initialization fails, 1855** then the return value from sqlite3_complete16() will be non-zero 1856** regardless of whether or not the input SQL is complete.)^ 1857** 1858** The input to [sqlite3_complete()] must be a zero-terminated 1859** UTF-8 string. 1860** 1861** The input to [sqlite3_complete16()] must be a zero-terminated 1862** UTF-16 string in native byte order. 1863*/ 1864int sqlite3_complete(const char *sql); 1865int sqlite3_complete16(const void *sql); 1866 1867/* 1868** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 1869** 1870** ^This routine sets a callback function that might be invoked whenever 1871** an attempt is made to open a database table that another thread 1872** or process has locked. 1873** 1874** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1875** is returned immediately upon encountering the lock. ^If the busy callback 1876** is not NULL, then the callback might be invoked with two arguments. 1877** 1878** ^The first argument to the busy handler is a copy of the void* pointer which 1879** is the third argument to sqlite3_busy_handler(). ^The second argument to 1880** the busy handler callback is the number of times that the busy handler has 1881** been invoked for this locking event. ^If the 1882** busy callback returns 0, then no additional attempts are made to 1883** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1884** ^If the callback returns non-zero, then another attempt 1885** is made to open the database for reading and the cycle repeats. 1886** 1887** The presence of a busy handler does not guarantee that it will be invoked 1888** when there is lock contention. ^If SQLite determines that invoking the busy 1889** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1890** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1891** Consider a scenario where one process is holding a read lock that 1892** it is trying to promote to a reserved lock and 1893** a second process is holding a reserved lock that it is trying 1894** to promote to an exclusive lock. The first process cannot proceed 1895** because it is blocked by the second and the second process cannot 1896** proceed because it is blocked by the first. If both processes 1897** invoke the busy handlers, neither will make any progress. Therefore, 1898** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1899** will induce the first process to release its read lock and allow 1900** the second process to proceed. 1901** 1902** ^The default busy callback is NULL. 1903** 1904** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1905** when SQLite is in the middle of a large transaction where all the 1906** changes will not fit into the in-memory cache. SQLite will 1907** already hold a RESERVED lock on the database file, but it needs 1908** to promote this lock to EXCLUSIVE so that it can spill cache 1909** pages into the database file without harm to concurrent 1910** readers. ^If it is unable to promote the lock, then the in-memory 1911** cache will be left in an inconsistent state and so the error 1912** code is promoted from the relatively benign [SQLITE_BUSY] to 1913** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 1914** forces an automatic rollback of the changes. See the 1915** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1916** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1917** this is important. 1918** 1919** ^(There can only be a single busy handler defined for each 1920** [database connection]. Setting a new busy handler clears any 1921** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 1922** will also set or clear the busy handler. 1923** 1924** The busy callback should not take any actions which modify the 1925** database connection that invoked the busy handler. Any such actions 1926** result in undefined behavior. 1927** 1928** A busy handler must not close the database connection 1929** or [prepared statement] that invoked the busy handler. 1930*/ 1931int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1932 1933/* 1934** CAPI3REF: Set A Busy Timeout 1935** 1936** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1937** for a specified amount of time when a table is locked. ^The handler 1938** will sleep multiple times until at least "ms" milliseconds of sleeping 1939** have accumulated. ^After at least "ms" milliseconds of sleeping, 1940** the handler returns 0 which causes [sqlite3_step()] to return 1941** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1942** 1943** ^Calling this routine with an argument less than or equal to zero 1944** turns off all busy handlers. 1945** 1946** ^(There can only be a single busy handler for a particular 1947** [database connection] any any given moment. If another busy handler 1948** was defined (using [sqlite3_busy_handler()]) prior to calling 1949** this routine, that other busy handler is cleared.)^ 1950*/ 1951int sqlite3_busy_timeout(sqlite3*, int ms); 1952 1953/* 1954** CAPI3REF: Convenience Routines For Running Queries 1955** 1956** This is a legacy interface that is preserved for backwards compatibility. 1957** Use of this interface is not recommended. 1958** 1959** Definition: A <b>result table</b> is memory data structure created by the 1960** [sqlite3_get_table()] interface. A result table records the 1961** complete query results from one or more queries. 1962** 1963** The table conceptually has a number of rows and columns. But 1964** these numbers are not part of the result table itself. These 1965** numbers are obtained separately. Let N be the number of rows 1966** and M be the number of columns. 1967** 1968** A result table is an array of pointers to zero-terminated UTF-8 strings. 1969** There are (N+1)*M elements in the array. The first M pointers point 1970** to zero-terminated strings that contain the names of the columns. 1971** The remaining entries all point to query results. NULL values result 1972** in NULL pointers. All other values are in their UTF-8 zero-terminated 1973** string representation as returned by [sqlite3_column_text()]. 1974** 1975** A result table might consist of one or more memory allocations. 1976** It is not safe to pass a result table directly to [sqlite3_free()]. 1977** A result table should be deallocated using [sqlite3_free_table()]. 1978** 1979** ^(As an example of the result table format, suppose a query result 1980** is as follows: 1981** 1982** <blockquote><pre> 1983** Name | Age 1984** ----------------------- 1985** Alice | 43 1986** Bob | 28 1987** Cindy | 21 1988** </pre></blockquote> 1989** 1990** There are two column (M==2) and three rows (N==3). Thus the 1991** result table has 8 entries. Suppose the result table is stored 1992** in an array names azResult. Then azResult holds this content: 1993** 1994** <blockquote><pre> 1995** azResult[0] = "Name"; 1996** azResult[1] = "Age"; 1997** azResult[2] = "Alice"; 1998** azResult[3] = "43"; 1999** azResult[4] = "Bob"; 2000** azResult[5] = "28"; 2001** azResult[6] = "Cindy"; 2002** azResult[7] = "21"; 2003** </pre></blockquote>)^ 2004** 2005** ^The sqlite3_get_table() function evaluates one or more 2006** semicolon-separated SQL statements in the zero-terminated UTF-8 2007** string of its 2nd parameter and returns a result table to the 2008** pointer given in its 3rd parameter. 2009** 2010** After the application has finished with the result from sqlite3_get_table(), 2011** it must pass the result table pointer to sqlite3_free_table() in order to 2012** release the memory that was malloced. Because of the way the 2013** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2014** function must not try to call [sqlite3_free()] directly. Only 2015** [sqlite3_free_table()] is able to release the memory properly and safely. 2016** 2017** The sqlite3_get_table() interface is implemented as a wrapper around 2018** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2019** to any internal data structures of SQLite. It uses only the public 2020** interface defined here. As a consequence, errors that occur in the 2021** wrapper layer outside of the internal [sqlite3_exec()] call are not 2022** reflected in subsequent calls to [sqlite3_errcode()] or 2023** [sqlite3_errmsg()]. 2024*/ 2025int sqlite3_get_table( 2026 sqlite3 *db, /* An open database */ 2027 const char *zSql, /* SQL to be evaluated */ 2028 char ***pazResult, /* Results of the query */ 2029 int *pnRow, /* Number of result rows written here */ 2030 int *pnColumn, /* Number of result columns written here */ 2031 char **pzErrmsg /* Error msg written here */ 2032); 2033void sqlite3_free_table(char **result); 2034 2035/* 2036** CAPI3REF: Formatted String Printing Functions 2037** 2038** These routines are work-alikes of the "printf()" family of functions 2039** from the standard C library. 2040** 2041** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2042** results into memory obtained from [sqlite3_malloc()]. 2043** The strings returned by these two routines should be 2044** released by [sqlite3_free()]. ^Both routines return a 2045** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2046** memory to hold the resulting string. 2047** 2048** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2049** the standard C library. The result is written into the 2050** buffer supplied as the second parameter whose size is given by 2051** the first parameter. Note that the order of the 2052** first two parameters is reversed from snprintf().)^ This is an 2053** historical accident that cannot be fixed without breaking 2054** backwards compatibility. ^(Note also that sqlite3_snprintf() 2055** returns a pointer to its buffer instead of the number of 2056** characters actually written into the buffer.)^ We admit that 2057** the number of characters written would be a more useful return 2058** value but we cannot change the implementation of sqlite3_snprintf() 2059** now without breaking compatibility. 2060** 2061** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2062** guarantees that the buffer is always zero-terminated. ^The first 2063** parameter "n" is the total size of the buffer, including space for 2064** the zero terminator. So the longest string that can be completely 2065** written will be n-1 characters. 2066** 2067** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2068** 2069** These routines all implement some additional formatting 2070** options that are useful for constructing SQL statements. 2071** All of the usual printf() formatting options apply. In addition, there 2072** is are "%q", "%Q", and "%z" options. 2073** 2074** ^(The %q option works like %s in that it substitutes a nul-terminated 2075** string from the argument list. But %q also doubles every '\'' character. 2076** %q is designed for use inside a string literal.)^ By doubling each '\'' 2077** character it escapes that character and allows it to be inserted into 2078** the string. 2079** 2080** For example, assume the string variable zText contains text as follows: 2081** 2082** <blockquote><pre> 2083** char *zText = "It's a happy day!"; 2084** </pre></blockquote> 2085** 2086** One can use this text in an SQL statement as follows: 2087** 2088** <blockquote><pre> 2089** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2090** sqlite3_exec(db, zSQL, 0, 0, 0); 2091** sqlite3_free(zSQL); 2092** </pre></blockquote> 2093** 2094** Because the %q format string is used, the '\'' character in zText 2095** is escaped and the SQL generated is as follows: 2096** 2097** <blockquote><pre> 2098** INSERT INTO table1 VALUES('It''s a happy day!') 2099** </pre></blockquote> 2100** 2101** This is correct. Had we used %s instead of %q, the generated SQL 2102** would have looked like this: 2103** 2104** <blockquote><pre> 2105** INSERT INTO table1 VALUES('It's a happy day!'); 2106** </pre></blockquote> 2107** 2108** This second example is an SQL syntax error. As a general rule you should 2109** always use %q instead of %s when inserting text into a string literal. 2110** 2111** ^(The %Q option works like %q except it also adds single quotes around 2112** the outside of the total string. Additionally, if the parameter in the 2113** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2114** single quotes).)^ So, for example, one could say: 2115** 2116** <blockquote><pre> 2117** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2118** sqlite3_exec(db, zSQL, 0, 0, 0); 2119** sqlite3_free(zSQL); 2120** </pre></blockquote> 2121** 2122** The code above will render a correct SQL statement in the zSQL 2123** variable even if the zText variable is a NULL pointer. 2124** 2125** ^(The "%z" formatting option works like "%s" but with the 2126** addition that after the string has been read and copied into 2127** the result, [sqlite3_free()] is called on the input string.)^ 2128*/ 2129char *sqlite3_mprintf(const char*,...); 2130char *sqlite3_vmprintf(const char*, va_list); 2131char *sqlite3_snprintf(int,char*,const char*, ...); 2132char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2133 2134/* 2135** CAPI3REF: Memory Allocation Subsystem 2136** 2137** The SQLite core uses these three routines for all of its own 2138** internal memory allocation needs. "Core" in the previous sentence 2139** does not include operating-system specific VFS implementation. The 2140** Windows VFS uses native malloc() and free() for some operations. 2141** 2142** ^The sqlite3_malloc() routine returns a pointer to a block 2143** of memory at least N bytes in length, where N is the parameter. 2144** ^If sqlite3_malloc() is unable to obtain sufficient free 2145** memory, it returns a NULL pointer. ^If the parameter N to 2146** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2147** a NULL pointer. 2148** 2149** ^Calling sqlite3_free() with a pointer previously returned 2150** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2151** that it might be reused. ^The sqlite3_free() routine is 2152** a no-op if is called with a NULL pointer. Passing a NULL pointer 2153** to sqlite3_free() is harmless. After being freed, memory 2154** should neither be read nor written. Even reading previously freed 2155** memory might result in a segmentation fault or other severe error. 2156** Memory corruption, a segmentation fault, or other severe error 2157** might result if sqlite3_free() is called with a non-NULL pointer that 2158** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2159** 2160** ^(The sqlite3_realloc() interface attempts to resize a 2161** prior memory allocation to be at least N bytes, where N is the 2162** second parameter. The memory allocation to be resized is the first 2163** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2164** is a NULL pointer then its behavior is identical to calling 2165** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2166** ^If the second parameter to sqlite3_realloc() is zero or 2167** negative then the behavior is exactly the same as calling 2168** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2169** ^sqlite3_realloc() returns a pointer to a memory allocation 2170** of at least N bytes in size or NULL if sufficient memory is unavailable. 2171** ^If M is the size of the prior allocation, then min(N,M) bytes 2172** of the prior allocation are copied into the beginning of buffer returned 2173** by sqlite3_realloc() and the prior allocation is freed. 2174** ^If sqlite3_realloc() returns NULL, then the prior allocation 2175** is not freed. 2176** 2177** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2178** is always aligned to at least an 8 byte boundary, or to a 2179** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2180** option is used. 2181** 2182** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2183** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2184** implementation of these routines to be omitted. That capability 2185** is no longer provided. Only built-in memory allocators can be used. 2186** 2187** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2188** the system malloc() and free() directly when converting 2189** filenames between the UTF-8 encoding used by SQLite 2190** and whatever filename encoding is used by the particular Windows 2191** installation. Memory allocation errors were detected, but 2192** they were reported back as [SQLITE_CANTOPEN] or 2193** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2194** 2195** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2196** must be either NULL or else pointers obtained from a prior 2197** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2198** not yet been released. 2199** 2200** The application must not read or write any part of 2201** a block of memory after it has been released using 2202** [sqlite3_free()] or [sqlite3_realloc()]. 2203*/ 2204void *sqlite3_malloc(int); 2205void *sqlite3_realloc(void*, int); 2206void sqlite3_free(void*); 2207 2208/* 2209** CAPI3REF: Memory Allocator Statistics 2210** 2211** SQLite provides these two interfaces for reporting on the status 2212** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2213** routines, which form the built-in memory allocation subsystem. 2214** 2215** ^The [sqlite3_memory_used()] routine returns the number of bytes 2216** of memory currently outstanding (malloced but not freed). 2217** ^The [sqlite3_memory_highwater()] routine returns the maximum 2218** value of [sqlite3_memory_used()] since the high-water mark 2219** was last reset. ^The values returned by [sqlite3_memory_used()] and 2220** [sqlite3_memory_highwater()] include any overhead 2221** added by SQLite in its implementation of [sqlite3_malloc()], 2222** but not overhead added by the any underlying system library 2223** routines that [sqlite3_malloc()] may call. 2224** 2225** ^The memory high-water mark is reset to the current value of 2226** [sqlite3_memory_used()] if and only if the parameter to 2227** [sqlite3_memory_highwater()] is true. ^The value returned 2228** by [sqlite3_memory_highwater(1)] is the high-water mark 2229** prior to the reset. 2230*/ 2231sqlite3_int64 sqlite3_memory_used(void); 2232sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2233 2234/* 2235** CAPI3REF: Pseudo-Random Number Generator 2236** 2237** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2238** select random [ROWID | ROWIDs] when inserting new records into a table that 2239** already uses the largest possible [ROWID]. The PRNG is also used for 2240** the build-in random() and randomblob() SQL functions. This interface allows 2241** applications to access the same PRNG for other purposes. 2242** 2243** ^A call to this routine stores N bytes of randomness into buffer P. 2244** 2245** ^The first time this routine is invoked (either internally or by 2246** the application) the PRNG is seeded using randomness obtained 2247** from the xRandomness method of the default [sqlite3_vfs] object. 2248** ^On all subsequent invocations, the pseudo-randomness is generated 2249** internally and without recourse to the [sqlite3_vfs] xRandomness 2250** method. 2251*/ 2252void sqlite3_randomness(int N, void *P); 2253 2254/* 2255** CAPI3REF: Compile-Time Authorization Callbacks 2256** 2257** ^This routine registers an authorizer callback with a particular 2258** [database connection], supplied in the first argument. 2259** ^The authorizer callback is invoked as SQL statements are being compiled 2260** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2261** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2262** points during the compilation process, as logic is being created 2263** to perform various actions, the authorizer callback is invoked to 2264** see if those actions are allowed. ^The authorizer callback should 2265** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2266** specific action but allow the SQL statement to continue to be 2267** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2268** rejected with an error. ^If the authorizer callback returns 2269** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2270** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2271** the authorizer will fail with an error message. 2272** 2273** When the callback returns [SQLITE_OK], that means the operation 2274** requested is ok. ^When the callback returns [SQLITE_DENY], the 2275** [sqlite3_prepare_v2()] or equivalent call that triggered the 2276** authorizer will fail with an error message explaining that 2277** access is denied. 2278** 2279** ^The first parameter to the authorizer callback is a copy of the third 2280** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2281** to the callback is an integer [SQLITE_COPY | action code] that specifies 2282** the particular action to be authorized. ^The third through sixth parameters 2283** to the callback are zero-terminated strings that contain additional 2284** details about the action to be authorized. 2285** 2286** ^If the action code is [SQLITE_READ] 2287** and the callback returns [SQLITE_IGNORE] then the 2288** [prepared statement] statement is constructed to substitute 2289** a NULL value in place of the table column that would have 2290** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2291** return can be used to deny an untrusted user access to individual 2292** columns of a table. 2293** ^If the action code is [SQLITE_DELETE] and the callback returns 2294** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2295** [truncate optimization] is disabled and all rows are deleted individually. 2296** 2297** An authorizer is used when [sqlite3_prepare | preparing] 2298** SQL statements from an untrusted source, to ensure that the SQL statements 2299** do not try to access data they are not allowed to see, or that they do not 2300** try to execute malicious statements that damage the database. For 2301** example, an application may allow a user to enter arbitrary 2302** SQL queries for evaluation by a database. But the application does 2303** not want the user to be able to make arbitrary changes to the 2304** database. An authorizer could then be put in place while the 2305** user-entered SQL is being [sqlite3_prepare | prepared] that 2306** disallows everything except [SELECT] statements. 2307** 2308** Applications that need to process SQL from untrusted sources 2309** might also consider lowering resource limits using [sqlite3_limit()] 2310** and limiting database size using the [max_page_count] [PRAGMA] 2311** in addition to using an authorizer. 2312** 2313** ^(Only a single authorizer can be in place on a database connection 2314** at a time. Each call to sqlite3_set_authorizer overrides the 2315** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2316** The authorizer is disabled by default. 2317** 2318** The authorizer callback must not do anything that will modify 2319** the database connection that invoked the authorizer callback. 2320** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2321** database connections for the meaning of "modify" in this paragraph. 2322** 2323** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2324** statement might be re-prepared during [sqlite3_step()] due to a 2325** schema change. Hence, the application should ensure that the 2326** correct authorizer callback remains in place during the [sqlite3_step()]. 2327** 2328** ^Note that the authorizer callback is invoked only during 2329** [sqlite3_prepare()] or its variants. Authorization is not 2330** performed during statement evaluation in [sqlite3_step()], unless 2331** as stated in the previous paragraph, sqlite3_step() invokes 2332** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2333*/ 2334int sqlite3_set_authorizer( 2335 sqlite3*, 2336 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2337 void *pUserData 2338); 2339 2340/* 2341** CAPI3REF: Authorizer Return Codes 2342** 2343** The [sqlite3_set_authorizer | authorizer callback function] must 2344** return either [SQLITE_OK] or one of these two constants in order 2345** to signal SQLite whether or not the action is permitted. See the 2346** [sqlite3_set_authorizer | authorizer documentation] for additional 2347** information. 2348** 2349** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] 2350** from the [sqlite3_vtab_on_conflict()] interface. 2351*/ 2352#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2353#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2354 2355/* 2356** CAPI3REF: Authorizer Action Codes 2357** 2358** The [sqlite3_set_authorizer()] interface registers a callback function 2359** that is invoked to authorize certain SQL statement actions. The 2360** second parameter to the callback is an integer code that specifies 2361** what action is being authorized. These are the integer action codes that 2362** the authorizer callback may be passed. 2363** 2364** These action code values signify what kind of operation is to be 2365** authorized. The 3rd and 4th parameters to the authorization 2366** callback function will be parameters or NULL depending on which of these 2367** codes is used as the second parameter. ^(The 5th parameter to the 2368** authorizer callback is the name of the database ("main", "temp", 2369** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2370** is the name of the inner-most trigger or view that is responsible for 2371** the access attempt or NULL if this access attempt is directly from 2372** top-level SQL code. 2373*/ 2374/******************************************* 3rd ************ 4th ***********/ 2375#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2376#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2377#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2378#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2379#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2380#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2381#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2382#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2383#define SQLITE_DELETE 9 /* Table Name NULL */ 2384#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2385#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2386#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2387#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2388#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2389#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2390#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2391#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2392#define SQLITE_INSERT 18 /* Table Name NULL */ 2393#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2394#define SQLITE_READ 20 /* Table Name Column Name */ 2395#define SQLITE_SELECT 21 /* NULL NULL */ 2396#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2397#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2398#define SQLITE_ATTACH 24 /* Filename NULL */ 2399#define SQLITE_DETACH 25 /* Database Name NULL */ 2400#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2401#define SQLITE_REINDEX 27 /* Index Name NULL */ 2402#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2403#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2404#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2405#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2406#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2407#define SQLITE_COPY 0 /* No longer used */ 2408 2409/* 2410** CAPI3REF: Tracing And Profiling Functions 2411** 2412** These routines register callback functions that can be used for 2413** tracing and profiling the execution of SQL statements. 2414** 2415** ^The callback function registered by sqlite3_trace() is invoked at 2416** various times when an SQL statement is being run by [sqlite3_step()]. 2417** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2418** SQL statement text as the statement first begins executing. 2419** ^(Additional sqlite3_trace() callbacks might occur 2420** as each triggered subprogram is entered. The callbacks for triggers 2421** contain a UTF-8 SQL comment that identifies the trigger.)^ 2422** 2423** ^The callback function registered by sqlite3_profile() is invoked 2424** as each SQL statement finishes. ^The profile callback contains 2425** the original statement text and an estimate of wall-clock time 2426** of how long that statement took to run. ^The profile callback 2427** time is in units of nanoseconds, however the current implementation 2428** is only capable of millisecond resolution so the six least significant 2429** digits in the time are meaningless. Future versions of SQLite 2430** might provide greater resolution on the profiler callback. The 2431** sqlite3_profile() function is considered experimental and is 2432** subject to change in future versions of SQLite. 2433*/ 2434void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2435SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2436 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2437 2438/* 2439** CAPI3REF: Query Progress Callbacks 2440** 2441** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2442** function X to be invoked periodically during long running calls to 2443** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2444** database connection D. An example use for this 2445** interface is to keep a GUI updated during a large query. 2446** 2447** ^The parameter P is passed through as the only parameter to the 2448** callback function X. ^The parameter N is the number of 2449** [virtual machine instructions] that are evaluated between successive 2450** invocations of the callback X. 2451** 2452** ^Only a single progress handler may be defined at one time per 2453** [database connection]; setting a new progress handler cancels the 2454** old one. ^Setting parameter X to NULL disables the progress handler. 2455** ^The progress handler is also disabled by setting N to a value less 2456** than 1. 2457** 2458** ^If the progress callback returns non-zero, the operation is 2459** interrupted. This feature can be used to implement a 2460** "Cancel" button on a GUI progress dialog box. 2461** 2462** The progress handler callback must not do anything that will modify 2463** the database connection that invoked the progress handler. 2464** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2465** database connections for the meaning of "modify" in this paragraph. 2466** 2467*/ 2468void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2469 2470/* 2471** CAPI3REF: Opening A New Database Connection 2472** 2473** ^These routines open an SQLite database file as specified by the 2474** filename argument. ^The filename argument is interpreted as UTF-8 for 2475** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2476** order for sqlite3_open16(). ^(A [database connection] handle is usually 2477** returned in *ppDb, even if an error occurs. The only exception is that 2478** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2479** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2480** object.)^ ^(If the database is opened (and/or created) successfully, then 2481** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2482** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2483** an English language description of the error following a failure of any 2484** of the sqlite3_open() routines. 2485** 2486** ^The default encoding for the database will be UTF-8 if 2487** sqlite3_open() or sqlite3_open_v2() is called and 2488** UTF-16 in the native byte order if sqlite3_open16() is used. 2489** 2490** Whether or not an error occurs when it is opened, resources 2491** associated with the [database connection] handle should be released by 2492** passing it to [sqlite3_close()] when it is no longer required. 2493** 2494** The sqlite3_open_v2() interface works like sqlite3_open() 2495** except that it accepts two additional parameters for additional control 2496** over the new database connection. ^(The flags parameter to 2497** sqlite3_open_v2() can take one of 2498** the following three values, optionally combined with the 2499** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2500** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2501** 2502** <dl> 2503** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2504** <dd>The database is opened in read-only mode. If the database does not 2505** already exist, an error is returned.</dd>)^ 2506** 2507** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2508** <dd>The database is opened for reading and writing if possible, or reading 2509** only if the file is write protected by the operating system. In either 2510** case the database must already exist, otherwise an error is returned.</dd>)^ 2511** 2512** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2513** <dd>The database is opened for reading and writing, and is created if 2514** it does not already exist. This is the behavior that is always used for 2515** sqlite3_open() and sqlite3_open16().</dd>)^ 2516** </dl> 2517** 2518** If the 3rd parameter to sqlite3_open_v2() is not one of the 2519** combinations shown above optionally combined with other 2520** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2521** then the behavior is undefined. 2522** 2523** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2524** opens in the multi-thread [threading mode] as long as the single-thread 2525** mode has not been set at compile-time or start-time. ^If the 2526** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2527** in the serialized [threading mode] unless single-thread was 2528** previously selected at compile-time or start-time. 2529** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2530** eligible to use [shared cache mode], regardless of whether or not shared 2531** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2532** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2533** participate in [shared cache mode] even if it is enabled. 2534** 2535** ^The fourth parameter to sqlite3_open_v2() is the name of the 2536** [sqlite3_vfs] object that defines the operating system interface that 2537** the new database connection should use. ^If the fourth parameter is 2538** a NULL pointer then the default [sqlite3_vfs] object is used. 2539** 2540** ^If the filename is ":memory:", then a private, temporary in-memory database 2541** is created for the connection. ^This in-memory database will vanish when 2542** the database connection is closed. Future versions of SQLite might 2543** make use of additional special filenames that begin with the ":" character. 2544** It is recommended that when a database filename actually does begin with 2545** a ":" character you should prefix the filename with a pathname such as 2546** "./" to avoid ambiguity. 2547** 2548** ^If the filename is an empty string, then a private, temporary 2549** on-disk database will be created. ^This private database will be 2550** automatically deleted as soon as the database connection is closed. 2551** 2552** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2553** 2554** ^If [URI filename] interpretation is enabled, and the filename argument 2555** begins with "file:", then the filename is interpreted as a URI. ^URI 2556** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2557** set in the fourth argument to sqlite3_open_v2(), or if it has 2558** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2559** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2560** As of SQLite version 3.7.7, URI filename interpretation is turned off 2561** by default, but future releases of SQLite might enable URI filename 2562** interpretation by default. See "[URI filenames]" for additional 2563** information. 2564** 2565** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2566** authority, then it must be either an empty string or the string 2567** "localhost". ^If the authority is not an empty string or "localhost", an 2568** error is returned to the caller. ^The fragment component of a URI, if 2569** present, is ignored. 2570** 2571** ^SQLite uses the path component of the URI as the name of the disk file 2572** which contains the database. ^If the path begins with a '/' character, 2573** then it is interpreted as an absolute path. ^If the path does not begin 2574** with a '/' (meaning that the authority section is omitted from the URI) 2575** then the path is interpreted as a relative path. 2576** ^On windows, the first component of an absolute path 2577** is a drive specification (e.g. "C:"). 2578** 2579** [[core URI query parameters]] 2580** The query component of a URI may contain parameters that are interpreted 2581** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2582** SQLite interprets the following three query parameters: 2583** 2584** <ul> 2585** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2586** a VFS object that provides the operating system interface that should 2587** be used to access the database file on disk. ^If this option is set to 2588** an empty string the default VFS object is used. ^Specifying an unknown 2589** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2590** present, then the VFS specified by the option takes precedence over 2591** the value passed as the fourth parameter to sqlite3_open_v2(). 2592** 2593** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2594** "rwc", or "memory". Attempting to set it to any other value is 2595** an error)^. 2596** ^If "ro" is specified, then the database is opened for read-only 2597** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2598** third argument to sqlite3_prepare_v2(). ^If the mode option is set to 2599** "rw", then the database is opened for read-write (but not create) 2600** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2601** been set. ^Value "rwc" is equivalent to setting both 2602** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2603** set to "memory" then a pure [in-memory database] that never reads 2604** or writes from disk is used. ^It is an error to specify a value for 2605** the mode parameter that is less restrictive than that specified by 2606** the flags passed in the third parameter to sqlite3_open_v2(). 2607** 2608** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2609** "private". ^Setting it to "shared" is equivalent to setting the 2610** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2611** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2612** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2613** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2614** a URI filename, its value overrides any behaviour requested by setting 2615** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2616** </ul> 2617** 2618** ^Specifying an unknown parameter in the query component of a URI is not an 2619** error. Future versions of SQLite might understand additional query 2620** parameters. See "[query parameters with special meaning to SQLite]" for 2621** additional information. 2622** 2623** [[URI filename examples]] <h3>URI filename examples</h3> 2624** 2625** <table border="1" align=center cellpadding=5> 2626** <tr><th> URI filenames <th> Results 2627** <tr><td> file:data.db <td> 2628** Open the file "data.db" in the current directory. 2629** <tr><td> file:/home/fred/data.db<br> 2630** file:///home/fred/data.db <br> 2631** file://localhost/home/fred/data.db <br> <td> 2632** Open the database file "/home/fred/data.db". 2633** <tr><td> file://darkstar/home/fred/data.db <td> 2634** An error. "darkstar" is not a recognized authority. 2635** <tr><td style="white-space:nowrap"> 2636** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2637** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2638** C:. Note that the %20 escaping in this example is not strictly 2639** necessary - space characters can be used literally 2640** in URI filenames. 2641** <tr><td> file:data.db?mode=ro&cache=private <td> 2642** Open file "data.db" in the current directory for read-only access. 2643** Regardless of whether or not shared-cache mode is enabled by 2644** default, use a private cache. 2645** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> 2646** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". 2647** <tr><td> file:data.db?mode=readonly <td> 2648** An error. "readonly" is not a valid option for the "mode" parameter. 2649** </table> 2650** 2651** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2652** query components of a URI. A hexadecimal escape sequence consists of a 2653** percent sign - "%" - followed by exactly two hexadecimal digits 2654** specifying an octet value. ^Before the path or query components of a 2655** URI filename are interpreted, they are encoded using UTF-8 and all 2656** hexadecimal escape sequences replaced by a single byte containing the 2657** corresponding octet. If this process generates an invalid UTF-8 encoding, 2658** the results are undefined. 2659** 2660** <b>Note to Windows users:</b> The encoding used for the filename argument 2661** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2662** codepage is currently defined. Filenames containing international 2663** characters must be converted to UTF-8 prior to passing them into 2664** sqlite3_open() or sqlite3_open_v2(). 2665*/ 2666int sqlite3_open( 2667 const char *filename, /* Database filename (UTF-8) */ 2668 sqlite3 **ppDb /* OUT: SQLite db handle */ 2669); 2670int sqlite3_open16( 2671 const void *filename, /* Database filename (UTF-16) */ 2672 sqlite3 **ppDb /* OUT: SQLite db handle */ 2673); 2674int sqlite3_open_v2( 2675 const char *filename, /* Database filename (UTF-8) */ 2676 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2677 int flags, /* Flags */ 2678 const char *zVfs /* Name of VFS module to use */ 2679); 2680 2681/* 2682** CAPI3REF: Obtain Values For URI Parameters 2683** 2684** These are utility routines, useful to VFS implementations, that check 2685** to see if a database file was a URI that contained a specific query 2686** parameter, and if so obtains the value of that query parameter. 2687** 2688** If F is the database filename pointer passed into the xOpen() method of 2689** a VFS implementation when the flags parameter to xOpen() has one or 2690** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2691** P is the name of the query parameter, then 2692** sqlite3_uri_parameter(F,P) returns the value of the P 2693** parameter if it exists or a NULL pointer if P does not appear as a 2694** query parameter on F. If P is a query parameter of F 2695** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2696** a pointer to an empty string. 2697** 2698** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2699** parameter and returns true (1) or false (0) according to the value 2700** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 2701** value of query parameter P is one of "yes", "true", or "on" in any 2702** case or if the value begins with a non-zero number. The 2703** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 2704** query parameter P is one of "no", "false", or "off" in any case or 2705** if the value begins with a numeric zero. If P is not a query 2706** parameter on F or if the value of P is does not match any of the 2707** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2708** 2709** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2710** 64-bit signed integer and returns that integer, or D if P does not 2711** exist. If the value of P is something other than an integer, then 2712** zero is returned. 2713** 2714** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2715** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2716** is not a database file pathname pointer that SQLite passed into the xOpen 2717** VFS method, then the behavior of this routine is undefined and probably 2718** undesirable. 2719*/ 2720const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2721int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 2722sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 2723 2724 2725/* 2726** CAPI3REF: Error Codes And Messages 2727** 2728** ^The sqlite3_errcode() interface returns the numeric [result code] or 2729** [extended result code] for the most recent failed sqlite3_* API call 2730** associated with a [database connection]. If a prior API call failed 2731** but the most recent API call succeeded, the return value from 2732** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2733** interface is the same except that it always returns the 2734** [extended result code] even when extended result codes are 2735** disabled. 2736** 2737** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2738** text that describes the error, as either UTF-8 or UTF-16 respectively. 2739** ^(Memory to hold the error message string is managed internally. 2740** The application does not need to worry about freeing the result. 2741** However, the error string might be overwritten or deallocated by 2742** subsequent calls to other SQLite interface functions.)^ 2743** 2744** When the serialized [threading mode] is in use, it might be the 2745** case that a second error occurs on a separate thread in between 2746** the time of the first error and the call to these interfaces. 2747** When that happens, the second error will be reported since these 2748** interfaces always report the most recent result. To avoid 2749** this, each thread can obtain exclusive use of the [database connection] D 2750** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2751** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2752** all calls to the interfaces listed here are completed. 2753** 2754** If an interface fails with SQLITE_MISUSE, that means the interface 2755** was invoked incorrectly by the application. In that case, the 2756** error code and message may or may not be set. 2757*/ 2758int sqlite3_errcode(sqlite3 *db); 2759int sqlite3_extended_errcode(sqlite3 *db); 2760const char *sqlite3_errmsg(sqlite3*); 2761const void *sqlite3_errmsg16(sqlite3*); 2762 2763/* 2764** CAPI3REF: SQL Statement Object 2765** KEYWORDS: {prepared statement} {prepared statements} 2766** 2767** An instance of this object represents a single SQL statement. 2768** This object is variously known as a "prepared statement" or a 2769** "compiled SQL statement" or simply as a "statement". 2770** 2771** The life of a statement object goes something like this: 2772** 2773** <ol> 2774** <li> Create the object using [sqlite3_prepare_v2()] or a related 2775** function. 2776** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2777** interfaces. 2778** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2779** <li> Reset the statement using [sqlite3_reset()] then go back 2780** to step 2. Do this zero or more times. 2781** <li> Destroy the object using [sqlite3_finalize()]. 2782** </ol> 2783** 2784** Refer to documentation on individual methods above for additional 2785** information. 2786*/ 2787typedef struct sqlite3_stmt sqlite3_stmt; 2788 2789/* 2790** CAPI3REF: Run-time Limits 2791** 2792** ^(This interface allows the size of various constructs to be limited 2793** on a connection by connection basis. The first parameter is the 2794** [database connection] whose limit is to be set or queried. The 2795** second parameter is one of the [limit categories] that define a 2796** class of constructs to be size limited. The third parameter is the 2797** new limit for that construct.)^ 2798** 2799** ^If the new limit is a negative number, the limit is unchanged. 2800** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2801** [limits | hard upper bound] 2802** set at compile-time by a C preprocessor macro called 2803** [limits | SQLITE_MAX_<i>NAME</i>]. 2804** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2805** ^Attempts to increase a limit above its hard upper bound are 2806** silently truncated to the hard upper bound. 2807** 2808** ^Regardless of whether or not the limit was changed, the 2809** [sqlite3_limit()] interface returns the prior value of the limit. 2810** ^Hence, to find the current value of a limit without changing it, 2811** simply invoke this interface with the third parameter set to -1. 2812** 2813** Run-time limits are intended for use in applications that manage 2814** both their own internal database and also databases that are controlled 2815** by untrusted external sources. An example application might be a 2816** web browser that has its own databases for storing history and 2817** separate databases controlled by JavaScript applications downloaded 2818** off the Internet. The internal databases can be given the 2819** large, default limits. Databases managed by external sources can 2820** be given much smaller limits designed to prevent a denial of service 2821** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2822** interface to further control untrusted SQL. The size of the database 2823** created by an untrusted script can be contained using the 2824** [max_page_count] [PRAGMA]. 2825** 2826** New run-time limit categories may be added in future releases. 2827*/ 2828int sqlite3_limit(sqlite3*, int id, int newVal); 2829 2830/* 2831** CAPI3REF: Run-Time Limit Categories 2832** KEYWORDS: {limit category} {*limit categories} 2833** 2834** These constants define various performance limits 2835** that can be lowered at run-time using [sqlite3_limit()]. 2836** The synopsis of the meanings of the various limits is shown below. 2837** Additional information is available at [limits | Limits in SQLite]. 2838** 2839** <dl> 2840** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 2841** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 2842** 2843** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2844** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 2845** 2846** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 2847** <dd>The maximum number of columns in a table definition or in the 2848** result set of a [SELECT] or the maximum number of columns in an index 2849** or in an ORDER BY or GROUP BY clause.</dd>)^ 2850** 2851** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2852** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 2853** 2854** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2855** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 2856** 2857** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 2858** <dd>The maximum number of instructions in a virtual machine program 2859** used to implement an SQL statement. This limit is not currently 2860** enforced, though that might be added in some future release of 2861** SQLite.</dd>)^ 2862** 2863** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2864** <dd>The maximum number of arguments on a function.</dd>)^ 2865** 2866** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 2867** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 2868** 2869** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 2870** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2871** <dd>The maximum length of the pattern argument to the [LIKE] or 2872** [GLOB] operators.</dd>)^ 2873** 2874** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 2875** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2876** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 2877** 2878** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 2879** <dd>The maximum depth of recursion for triggers.</dd>)^ 2880** </dl> 2881*/ 2882#define SQLITE_LIMIT_LENGTH 0 2883#define SQLITE_LIMIT_SQL_LENGTH 1 2884#define SQLITE_LIMIT_COLUMN 2 2885#define SQLITE_LIMIT_EXPR_DEPTH 3 2886#define SQLITE_LIMIT_COMPOUND_SELECT 4 2887#define SQLITE_LIMIT_VDBE_OP 5 2888#define SQLITE_LIMIT_FUNCTION_ARG 6 2889#define SQLITE_LIMIT_ATTACHED 7 2890#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2891#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2892#define SQLITE_LIMIT_TRIGGER_DEPTH 10 2893 2894/* 2895** CAPI3REF: Compiling An SQL Statement 2896** KEYWORDS: {SQL statement compiler} 2897** 2898** To execute an SQL query, it must first be compiled into a byte-code 2899** program using one of these routines. 2900** 2901** The first argument, "db", is a [database connection] obtained from a 2902** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 2903** [sqlite3_open16()]. The database connection must not have been closed. 2904** 2905** The second argument, "zSql", is the statement to be compiled, encoded 2906** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2907** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2908** use UTF-16. 2909** 2910** ^If the nByte argument is less than zero, then zSql is read up to the 2911** first zero terminator. ^If nByte is non-negative, then it is the maximum 2912** number of bytes read from zSql. ^When nByte is non-negative, the 2913** zSql string ends at either the first '\000' or '\u0000' character or 2914** the nByte-th byte, whichever comes first. If the caller knows 2915** that the supplied string is nul-terminated, then there is a small 2916** performance advantage to be gained by passing an nByte parameter that 2917** is equal to the number of bytes in the input string <i>including</i> 2918** the nul-terminator bytes as this saves SQLite from having to 2919** make a copy of the input string. 2920** 2921** ^If pzTail is not NULL then *pzTail is made to point to the first byte 2922** past the end of the first SQL statement in zSql. These routines only 2923** compile the first statement in zSql, so *pzTail is left pointing to 2924** what remains uncompiled. 2925** 2926** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 2927** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 2928** to NULL. ^If the input text contains no SQL (if the input is an empty 2929** string or a comment) then *ppStmt is set to NULL. 2930** The calling procedure is responsible for deleting the compiled 2931** SQL statement using [sqlite3_finalize()] after it has finished with it. 2932** ppStmt may not be NULL. 2933** 2934** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 2935** otherwise an [error code] is returned. 2936** 2937** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2938** recommended for all new programs. The two older interfaces are retained 2939** for backwards compatibility, but their use is discouraged. 2940** ^In the "v2" interfaces, the prepared statement 2941** that is returned (the [sqlite3_stmt] object) contains a copy of the 2942** original SQL text. This causes the [sqlite3_step()] interface to 2943** behave differently in three ways: 2944** 2945** <ol> 2946** <li> 2947** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2948** always used to do, [sqlite3_step()] will automatically recompile the SQL 2949** statement and try to run it again. 2950** </li> 2951** 2952** <li> 2953** ^When an error occurs, [sqlite3_step()] will return one of the detailed 2954** [error codes] or [extended error codes]. ^The legacy behavior was that 2955** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2956** and the application would have to make a second call to [sqlite3_reset()] 2957** in order to find the underlying cause of the problem. With the "v2" prepare 2958** interfaces, the underlying reason for the error is returned immediately. 2959** </li> 2960** 2961** <li> 2962** ^If the specific value bound to [parameter | host parameter] in the 2963** WHERE clause might influence the choice of query plan for a statement, 2964** then the statement will be automatically recompiled, as if there had been 2965** a schema change, on the first [sqlite3_step()] call following any change 2966** to the [sqlite3_bind_text | bindings] of that [parameter]. 2967** ^The specific value of WHERE-clause [parameter] might influence the 2968** choice of query plan if the parameter is the left-hand side of a [LIKE] 2969** or [GLOB] operator or if the parameter is compared to an indexed column 2970** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 2971** the 2972** </li> 2973** </ol> 2974*/ 2975int sqlite3_prepare( 2976 sqlite3 *db, /* Database handle */ 2977 const char *zSql, /* SQL statement, UTF-8 encoded */ 2978 int nByte, /* Maximum length of zSql in bytes. */ 2979 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2980 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2981); 2982int sqlite3_prepare_v2( 2983 sqlite3 *db, /* Database handle */ 2984 const char *zSql, /* SQL statement, UTF-8 encoded */ 2985 int nByte, /* Maximum length of zSql in bytes. */ 2986 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2987 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2988); 2989int sqlite3_prepare16( 2990 sqlite3 *db, /* Database handle */ 2991 const void *zSql, /* SQL statement, UTF-16 encoded */ 2992 int nByte, /* Maximum length of zSql in bytes. */ 2993 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2994 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2995); 2996int sqlite3_prepare16_v2( 2997 sqlite3 *db, /* Database handle */ 2998 const void *zSql, /* SQL statement, UTF-16 encoded */ 2999 int nByte, /* Maximum length of zSql in bytes. */ 3000 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3001 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3002); 3003 3004/* 3005** CAPI3REF: Retrieving Statement SQL 3006** 3007** ^This interface can be used to retrieve a saved copy of the original 3008** SQL text used to create a [prepared statement] if that statement was 3009** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3010*/ 3011const char *sqlite3_sql(sqlite3_stmt *pStmt); 3012 3013/* 3014** CAPI3REF: Determine If An SQL Statement Writes The Database 3015** 3016** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3017** and only if the [prepared statement] X makes no direct changes to 3018** the content of the database file. 3019** 3020** Note that [application-defined SQL functions] or 3021** [virtual tables] might change the database indirectly as a side effect. 3022** ^(For example, if an application defines a function "eval()" that 3023** calls [sqlite3_exec()], then the following SQL statement would 3024** change the database file through side-effects: 3025** 3026** <blockquote><pre> 3027** SELECT eval('DELETE FROM t1') FROM t2; 3028** </pre></blockquote> 3029** 3030** But because the [SELECT] statement does not change the database file 3031** directly, sqlite3_stmt_readonly() would still return true.)^ 3032** 3033** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3034** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3035** since the statements themselves do not actually modify the database but 3036** rather they control the timing of when other statements modify the 3037** database. ^The [ATTACH] and [DETACH] statements also cause 3038** sqlite3_stmt_readonly() to return true since, while those statements 3039** change the configuration of a database connection, they do not make 3040** changes to the content of the database files on disk. 3041*/ 3042int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3043 3044/* 3045** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3046** 3047** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3048** [prepared statement] S has been stepped at least once using 3049** [sqlite3_step(S)] but has not run to completion and/or has not 3050** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3051** interface returns false if S is a NULL pointer. If S is not a 3052** NULL pointer and is not a pointer to a valid [prepared statement] 3053** object, then the behavior is undefined and probably undesirable. 3054** 3055** This interface can be used in combination [sqlite3_next_stmt()] 3056** to locate all prepared statements associated with a database 3057** connection that are in need of being reset. This can be used, 3058** for example, in diagnostic routines to search for prepared 3059** statements that are holding a transaction open. 3060*/ 3061int sqlite3_stmt_busy(sqlite3_stmt*); 3062 3063/* 3064** CAPI3REF: Dynamically Typed Value Object 3065** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3066** 3067** SQLite uses the sqlite3_value object to represent all values 3068** that can be stored in a database table. SQLite uses dynamic typing 3069** for the values it stores. ^Values stored in sqlite3_value objects 3070** can be integers, floating point values, strings, BLOBs, or NULL. 3071** 3072** An sqlite3_value object may be either "protected" or "unprotected". 3073** Some interfaces require a protected sqlite3_value. Other interfaces 3074** will accept either a protected or an unprotected sqlite3_value. 3075** Every interface that accepts sqlite3_value arguments specifies 3076** whether or not it requires a protected sqlite3_value. 3077** 3078** The terms "protected" and "unprotected" refer to whether or not 3079** a mutex is held. An internal mutex is held for a protected 3080** sqlite3_value object but no mutex is held for an unprotected 3081** sqlite3_value object. If SQLite is compiled to be single-threaded 3082** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3083** or if SQLite is run in one of reduced mutex modes 3084** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3085** then there is no distinction between protected and unprotected 3086** sqlite3_value objects and they can be used interchangeably. However, 3087** for maximum code portability it is recommended that applications 3088** still make the distinction between protected and unprotected 3089** sqlite3_value objects even when not strictly required. 3090** 3091** ^The sqlite3_value objects that are passed as parameters into the 3092** implementation of [application-defined SQL functions] are protected. 3093** ^The sqlite3_value object returned by 3094** [sqlite3_column_value()] is unprotected. 3095** Unprotected sqlite3_value objects may only be used with 3096** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3097** The [sqlite3_value_blob | sqlite3_value_type()] family of 3098** interfaces require protected sqlite3_value objects. 3099*/ 3100typedef struct Mem sqlite3_value; 3101 3102/* 3103** CAPI3REF: SQL Function Context Object 3104** 3105** The context in which an SQL function executes is stored in an 3106** sqlite3_context object. ^A pointer to an sqlite3_context object 3107** is always first parameter to [application-defined SQL functions]. 3108** The application-defined SQL function implementation will pass this 3109** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3110** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3111** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3112** and/or [sqlite3_set_auxdata()]. 3113*/ 3114typedef struct sqlite3_context sqlite3_context; 3115 3116/* 3117** CAPI3REF: Binding Values To Prepared Statements 3118** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3119** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3120** 3121** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3122** literals may be replaced by a [parameter] that matches one of following 3123** templates: 3124** 3125** <ul> 3126** <li> ? 3127** <li> ?NNN 3128** <li> :VVV 3129** <li> @VVV 3130** <li> $VVV 3131** </ul> 3132** 3133** In the templates above, NNN represents an integer literal, 3134** and VVV represents an alphanumeric identifier.)^ ^The values of these 3135** parameters (also called "host parameter names" or "SQL parameters") 3136** can be set using the sqlite3_bind_*() routines defined here. 3137** 3138** ^The first argument to the sqlite3_bind_*() routines is always 3139** a pointer to the [sqlite3_stmt] object returned from 3140** [sqlite3_prepare_v2()] or its variants. 3141** 3142** ^The second argument is the index of the SQL parameter to be set. 3143** ^The leftmost SQL parameter has an index of 1. ^When the same named 3144** SQL parameter is used more than once, second and subsequent 3145** occurrences have the same index as the first occurrence. 3146** ^The index for named parameters can be looked up using the 3147** [sqlite3_bind_parameter_index()] API if desired. ^The index 3148** for "?NNN" parameters is the value of NNN. 3149** ^The NNN value must be between 1 and the [sqlite3_limit()] 3150** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3151** 3152** ^The third argument is the value to bind to the parameter. 3153** 3154** ^(In those routines that have a fourth argument, its value is the 3155** number of bytes in the parameter. To be clear: the value is the 3156** number of <u>bytes</u> in the value, not the number of characters.)^ 3157** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3158** is negative, then the length of the string is 3159** the number of bytes up to the first zero terminator. 3160** If the fourth parameter to sqlite3_bind_blob() is negative, then 3161** the behavior is undefined. 3162** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3163** or sqlite3_bind_text16() then that parameter must be the byte offset 3164** where the NUL terminator would occur assuming the string were NUL 3165** terminated. If any NUL characters occur at byte offsets less than 3166** the value of the fourth parameter then the resulting string value will 3167** contain embedded NULs. The result of expressions involving strings 3168** with embedded NULs is undefined. 3169** 3170** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3171** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3172** string after SQLite has finished with it. ^The destructor is called 3173** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3174** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3175** ^If the fifth argument is 3176** the special value [SQLITE_STATIC], then SQLite assumes that the 3177** information is in static, unmanaged space and does not need to be freed. 3178** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3179** SQLite makes its own private copy of the data immediately, before 3180** the sqlite3_bind_*() routine returns. 3181** 3182** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3183** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3184** (just an integer to hold its size) while it is being processed. 3185** Zeroblobs are intended to serve as placeholders for BLOBs whose 3186** content is later written using 3187** [sqlite3_blob_open | incremental BLOB I/O] routines. 3188** ^A negative value for the zeroblob results in a zero-length BLOB. 3189** 3190** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3191** for the [prepared statement] or with a prepared statement for which 3192** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3193** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3194** routine is passed a [prepared statement] that has been finalized, the 3195** result is undefined and probably harmful. 3196** 3197** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3198** ^Unbound parameters are interpreted as NULL. 3199** 3200** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3201** [error code] if anything goes wrong. 3202** ^[SQLITE_RANGE] is returned if the parameter 3203** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3204** 3205** See also: [sqlite3_bind_parameter_count()], 3206** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3207*/ 3208int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3209int sqlite3_bind_double(sqlite3_stmt*, int, double); 3210int sqlite3_bind_int(sqlite3_stmt*, int, int); 3211int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3212int sqlite3_bind_null(sqlite3_stmt*, int); 3213int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3214int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3215int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3216int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3217 3218/* 3219** CAPI3REF: Number Of SQL Parameters 3220** 3221** ^This routine can be used to find the number of [SQL parameters] 3222** in a [prepared statement]. SQL parameters are tokens of the 3223** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3224** placeholders for values that are [sqlite3_bind_blob | bound] 3225** to the parameters at a later time. 3226** 3227** ^(This routine actually returns the index of the largest (rightmost) 3228** parameter. For all forms except ?NNN, this will correspond to the 3229** number of unique parameters. If parameters of the ?NNN form are used, 3230** there may be gaps in the list.)^ 3231** 3232** See also: [sqlite3_bind_blob|sqlite3_bind()], 3233** [sqlite3_bind_parameter_name()], and 3234** [sqlite3_bind_parameter_index()]. 3235*/ 3236int sqlite3_bind_parameter_count(sqlite3_stmt*); 3237 3238/* 3239** CAPI3REF: Name Of A Host Parameter 3240** 3241** ^The sqlite3_bind_parameter_name(P,N) interface returns 3242** the name of the N-th [SQL parameter] in the [prepared statement] P. 3243** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3244** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3245** respectively. 3246** In other words, the initial ":" or "$" or "@" or "?" 3247** is included as part of the name.)^ 3248** ^Parameters of the form "?" without a following integer have no name 3249** and are referred to as "nameless" or "anonymous parameters". 3250** 3251** ^The first host parameter has an index of 1, not 0. 3252** 3253** ^If the value N is out of range or if the N-th parameter is 3254** nameless, then NULL is returned. ^The returned string is 3255** always in UTF-8 encoding even if the named parameter was 3256** originally specified as UTF-16 in [sqlite3_prepare16()] or 3257** [sqlite3_prepare16_v2()]. 3258** 3259** See also: [sqlite3_bind_blob|sqlite3_bind()], 3260** [sqlite3_bind_parameter_count()], and 3261** [sqlite3_bind_parameter_index()]. 3262*/ 3263const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3264 3265/* 3266** CAPI3REF: Index Of A Parameter With A Given Name 3267** 3268** ^Return the index of an SQL parameter given its name. ^The 3269** index value returned is suitable for use as the second 3270** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3271** is returned if no matching parameter is found. ^The parameter 3272** name must be given in UTF-8 even if the original statement 3273** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3274** 3275** See also: [sqlite3_bind_blob|sqlite3_bind()], 3276** [sqlite3_bind_parameter_count()], and 3277** [sqlite3_bind_parameter_index()]. 3278*/ 3279int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3280 3281/* 3282** CAPI3REF: Reset All Bindings On A Prepared Statement 3283** 3284** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3285** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3286** ^Use this routine to reset all host parameters to NULL. 3287*/ 3288int sqlite3_clear_bindings(sqlite3_stmt*); 3289 3290/* 3291** CAPI3REF: Number Of Columns In A Result Set 3292** 3293** ^Return the number of columns in the result set returned by the 3294** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3295** statement that does not return data (for example an [UPDATE]). 3296** 3297** See also: [sqlite3_data_count()] 3298*/ 3299int sqlite3_column_count(sqlite3_stmt *pStmt); 3300 3301/* 3302** CAPI3REF: Column Names In A Result Set 3303** 3304** ^These routines return the name assigned to a particular column 3305** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3306** interface returns a pointer to a zero-terminated UTF-8 string 3307** and sqlite3_column_name16() returns a pointer to a zero-terminated 3308** UTF-16 string. ^The first parameter is the [prepared statement] 3309** that implements the [SELECT] statement. ^The second parameter is the 3310** column number. ^The leftmost column is number 0. 3311** 3312** ^The returned string pointer is valid until either the [prepared statement] 3313** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3314** reprepared by the first call to [sqlite3_step()] for a particular run 3315** or until the next call to 3316** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3317** 3318** ^If sqlite3_malloc() fails during the processing of either routine 3319** (for example during a conversion from UTF-8 to UTF-16) then a 3320** NULL pointer is returned. 3321** 3322** ^The name of a result column is the value of the "AS" clause for 3323** that column, if there is an AS clause. If there is no AS clause 3324** then the name of the column is unspecified and may change from 3325** one release of SQLite to the next. 3326*/ 3327const char *sqlite3_column_name(sqlite3_stmt*, int N); 3328const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3329 3330/* 3331** CAPI3REF: Source Of Data In A Query Result 3332** 3333** ^These routines provide a means to determine the database, table, and 3334** table column that is the origin of a particular result column in 3335** [SELECT] statement. 3336** ^The name of the database or table or column can be returned as 3337** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3338** the database name, the _table_ routines return the table name, and 3339** the origin_ routines return the column name. 3340** ^The returned string is valid until the [prepared statement] is destroyed 3341** using [sqlite3_finalize()] or until the statement is automatically 3342** reprepared by the first call to [sqlite3_step()] for a particular run 3343** or until the same information is requested 3344** again in a different encoding. 3345** 3346** ^The names returned are the original un-aliased names of the 3347** database, table, and column. 3348** 3349** ^The first argument to these interfaces is a [prepared statement]. 3350** ^These functions return information about the Nth result column returned by 3351** the statement, where N is the second function argument. 3352** ^The left-most column is column 0 for these routines. 3353** 3354** ^If the Nth column returned by the statement is an expression or 3355** subquery and is not a column value, then all of these functions return 3356** NULL. ^These routine might also return NULL if a memory allocation error 3357** occurs. ^Otherwise, they return the name of the attached database, table, 3358** or column that query result column was extracted from. 3359** 3360** ^As with all other SQLite APIs, those whose names end with "16" return 3361** UTF-16 encoded strings and the other functions return UTF-8. 3362** 3363** ^These APIs are only available if the library was compiled with the 3364** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3365** 3366** If two or more threads call one or more of these routines against the same 3367** prepared statement and column at the same time then the results are 3368** undefined. 3369** 3370** If two or more threads call one or more 3371** [sqlite3_column_database_name | column metadata interfaces] 3372** for the same [prepared statement] and result column 3373** at the same time then the results are undefined. 3374*/ 3375const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3376const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3377const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3378const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3379const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3380const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3381 3382/* 3383** CAPI3REF: Declared Datatype Of A Query Result 3384** 3385** ^(The first parameter is a [prepared statement]. 3386** If this statement is a [SELECT] statement and the Nth column of the 3387** returned result set of that [SELECT] is a table column (not an 3388** expression or subquery) then the declared type of the table 3389** column is returned.)^ ^If the Nth column of the result set is an 3390** expression or subquery, then a NULL pointer is returned. 3391** ^The returned string is always UTF-8 encoded. 3392** 3393** ^(For example, given the database schema: 3394** 3395** CREATE TABLE t1(c1 VARIANT); 3396** 3397** and the following statement to be compiled: 3398** 3399** SELECT c1 + 1, c1 FROM t1; 3400** 3401** this routine would return the string "VARIANT" for the second result 3402** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3403** 3404** ^SQLite uses dynamic run-time typing. ^So just because a column 3405** is declared to contain a particular type does not mean that the 3406** data stored in that column is of the declared type. SQLite is 3407** strongly typed, but the typing is dynamic not static. ^Type 3408** is associated with individual values, not with the containers 3409** used to hold those values. 3410*/ 3411const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3412const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3413 3414/* 3415** CAPI3REF: Evaluate An SQL Statement 3416** 3417** After a [prepared statement] has been prepared using either 3418** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3419** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3420** must be called one or more times to evaluate the statement. 3421** 3422** The details of the behavior of the sqlite3_step() interface depend 3423** on whether the statement was prepared using the newer "v2" interface 3424** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3425** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3426** new "v2" interface is recommended for new applications but the legacy 3427** interface will continue to be supported. 3428** 3429** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3430** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3431** ^With the "v2" interface, any of the other [result codes] or 3432** [extended result codes] might be returned as well. 3433** 3434** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3435** database locks it needs to do its job. ^If the statement is a [COMMIT] 3436** or occurs outside of an explicit transaction, then you can retry the 3437** statement. If the statement is not a [COMMIT] and occurs within an 3438** explicit transaction then you should rollback the transaction before 3439** continuing. 3440** 3441** ^[SQLITE_DONE] means that the statement has finished executing 3442** successfully. sqlite3_step() should not be called again on this virtual 3443** machine without first calling [sqlite3_reset()] to reset the virtual 3444** machine back to its initial state. 3445** 3446** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3447** is returned each time a new row of data is ready for processing by the 3448** caller. The values may be accessed using the [column access functions]. 3449** sqlite3_step() is called again to retrieve the next row of data. 3450** 3451** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3452** violation) has occurred. sqlite3_step() should not be called again on 3453** the VM. More information may be found by calling [sqlite3_errmsg()]. 3454** ^With the legacy interface, a more specific error code (for example, 3455** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3456** can be obtained by calling [sqlite3_reset()] on the 3457** [prepared statement]. ^In the "v2" interface, 3458** the more specific error code is returned directly by sqlite3_step(). 3459** 3460** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3461** Perhaps it was called on a [prepared statement] that has 3462** already been [sqlite3_finalize | finalized] or on one that had 3463** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3464** be the case that the same database connection is being used by two or 3465** more threads at the same moment in time. 3466** 3467** For all versions of SQLite up to and including 3.6.23.1, a call to 3468** [sqlite3_reset()] was required after sqlite3_step() returned anything 3469** other than [SQLITE_ROW] before any subsequent invocation of 3470** sqlite3_step(). Failure to reset the prepared statement using 3471** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3472** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3473** calling [sqlite3_reset()] automatically in this circumstance rather 3474** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3475** break because any application that ever receives an SQLITE_MISUSE error 3476** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3477** can be used to restore the legacy behavior. 3478** 3479** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3480** API always returns a generic error code, [SQLITE_ERROR], following any 3481** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3482** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3483** specific [error codes] that better describes the error. 3484** We admit that this is a goofy design. The problem has been fixed 3485** with the "v2" interface. If you prepare all of your SQL statements 3486** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3487** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3488** then the more specific [error codes] are returned directly 3489** by sqlite3_step(). The use of the "v2" interface is recommended. 3490*/ 3491int sqlite3_step(sqlite3_stmt*); 3492 3493/* 3494** CAPI3REF: Number of columns in a result set 3495** 3496** ^The sqlite3_data_count(P) interface returns the number of columns in the 3497** current row of the result set of [prepared statement] P. 3498** ^If prepared statement P does not have results ready to return 3499** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3500** interfaces) then sqlite3_data_count(P) returns 0. 3501** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3502** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3503** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3504** will return non-zero if previous call to [sqlite3_step](P) returned 3505** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3506** where it always returns zero since each step of that multi-step 3507** pragma returns 0 columns of data. 3508** 3509** See also: [sqlite3_column_count()] 3510*/ 3511int sqlite3_data_count(sqlite3_stmt *pStmt); 3512 3513/* 3514** CAPI3REF: Fundamental Datatypes 3515** KEYWORDS: SQLITE_TEXT 3516** 3517** ^(Every value in SQLite has one of five fundamental datatypes: 3518** 3519** <ul> 3520** <li> 64-bit signed integer 3521** <li> 64-bit IEEE floating point number 3522** <li> string 3523** <li> BLOB 3524** <li> NULL 3525** </ul>)^ 3526** 3527** These constants are codes for each of those types. 3528** 3529** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3530** for a completely different meaning. Software that links against both 3531** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3532** SQLITE_TEXT. 3533*/ 3534#define SQLITE_INTEGER 1 3535#define SQLITE_FLOAT 2 3536#define SQLITE_BLOB 4 3537#define SQLITE_NULL 5 3538#ifdef SQLITE_TEXT 3539# undef SQLITE_TEXT 3540#else 3541# define SQLITE_TEXT 3 3542#endif 3543#define SQLITE3_TEXT 3 3544 3545/* 3546** CAPI3REF: Result Values From A Query 3547** KEYWORDS: {column access functions} 3548** 3549** These routines form the "result set" interface. 3550** 3551** ^These routines return information about a single column of the current 3552** result row of a query. ^In every case the first argument is a pointer 3553** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3554** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3555** and the second argument is the index of the column for which information 3556** should be returned. ^The leftmost column of the result set has the index 0. 3557** ^The number of columns in the result can be determined using 3558** [sqlite3_column_count()]. 3559** 3560** If the SQL statement does not currently point to a valid row, or if the 3561** column index is out of range, the result is undefined. 3562** These routines may only be called when the most recent call to 3563** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3564** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3565** If any of these routines are called after [sqlite3_reset()] or 3566** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3567** something other than [SQLITE_ROW], the results are undefined. 3568** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3569** are called from a different thread while any of these routines 3570** are pending, then the results are undefined. 3571** 3572** ^The sqlite3_column_type() routine returns the 3573** [SQLITE_INTEGER | datatype code] for the initial data type 3574** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3575** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3576** returned by sqlite3_column_type() is only meaningful if no type 3577** conversions have occurred as described below. After a type conversion, 3578** the value returned by sqlite3_column_type() is undefined. Future 3579** versions of SQLite may change the behavior of sqlite3_column_type() 3580** following a type conversion. 3581** 3582** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3583** routine returns the number of bytes in that BLOB or string. 3584** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3585** the string to UTF-8 and then returns the number of bytes. 3586** ^If the result is a numeric value then sqlite3_column_bytes() uses 3587** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3588** the number of bytes in that string. 3589** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3590** 3591** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3592** routine returns the number of bytes in that BLOB or string. 3593** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3594** the string to UTF-16 and then returns the number of bytes. 3595** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3596** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3597** the number of bytes in that string. 3598** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3599** 3600** ^The values returned by [sqlite3_column_bytes()] and 3601** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3602** of the string. ^For clarity: the values returned by 3603** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3604** bytes in the string, not the number of characters. 3605** 3606** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3607** even empty strings, are always zero-terminated. ^The return 3608** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3609** 3610** ^The object returned by [sqlite3_column_value()] is an 3611** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3612** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3613** If the [unprotected sqlite3_value] object returned by 3614** [sqlite3_column_value()] is used in any other way, including calls 3615** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3616** or [sqlite3_value_bytes()], then the behavior is undefined. 3617** 3618** These routines attempt to convert the value where appropriate. ^For 3619** example, if the internal representation is FLOAT and a text result 3620** is requested, [sqlite3_snprintf()] is used internally to perform the 3621** conversion automatically. ^(The following table details the conversions 3622** that are applied: 3623** 3624** <blockquote> 3625** <table border="1"> 3626** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3627** 3628** <tr><td> NULL <td> INTEGER <td> Result is 0 3629** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3630** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3631** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3632** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3633** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3634** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3635** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3636** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3637** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3638** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3639** <tr><td> TEXT <td> FLOAT <td> Use atof() 3640** <tr><td> TEXT <td> BLOB <td> No change 3641** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3642** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3643** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3644** </table> 3645** </blockquote>)^ 3646** 3647** The table above makes reference to standard C library functions atoi() 3648** and atof(). SQLite does not really use these functions. It has its 3649** own equivalent internal routines. The atoi() and atof() names are 3650** used in the table for brevity and because they are familiar to most 3651** C programmers. 3652** 3653** Note that when type conversions occur, pointers returned by prior 3654** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3655** sqlite3_column_text16() may be invalidated. 3656** Type conversions and pointer invalidations might occur 3657** in the following cases: 3658** 3659** <ul> 3660** <li> The initial content is a BLOB and sqlite3_column_text() or 3661** sqlite3_column_text16() is called. A zero-terminator might 3662** need to be added to the string.</li> 3663** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3664** sqlite3_column_text16() is called. The content must be converted 3665** to UTF-16.</li> 3666** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3667** sqlite3_column_text() is called. The content must be converted 3668** to UTF-8.</li> 3669** </ul> 3670** 3671** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3672** not invalidate a prior pointer, though of course the content of the buffer 3673** that the prior pointer references will have been modified. Other kinds 3674** of conversion are done in place when it is possible, but sometimes they 3675** are not possible and in those cases prior pointers are invalidated. 3676** 3677** The safest and easiest to remember policy is to invoke these routines 3678** in one of the following ways: 3679** 3680** <ul> 3681** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3682** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3683** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3684** </ul> 3685** 3686** In other words, you should call sqlite3_column_text(), 3687** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3688** into the desired format, then invoke sqlite3_column_bytes() or 3689** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3690** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3691** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3692** with calls to sqlite3_column_bytes(). 3693** 3694** ^The pointers returned are valid until a type conversion occurs as 3695** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3696** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3697** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3698** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3699** [sqlite3_free()]. 3700** 3701** ^(If a memory allocation error occurs during the evaluation of any 3702** of these routines, a default value is returned. The default value 3703** is either the integer 0, the floating point number 0.0, or a NULL 3704** pointer. Subsequent calls to [sqlite3_errcode()] will return 3705** [SQLITE_NOMEM].)^ 3706*/ 3707const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3708int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3709int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3710double sqlite3_column_double(sqlite3_stmt*, int iCol); 3711int sqlite3_column_int(sqlite3_stmt*, int iCol); 3712sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3713const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3714const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3715int sqlite3_column_type(sqlite3_stmt*, int iCol); 3716sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3717 3718/* 3719** CAPI3REF: Destroy A Prepared Statement Object 3720** 3721** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3722** ^If the most recent evaluation of the statement encountered no errors 3723** or if the statement is never been evaluated, then sqlite3_finalize() returns 3724** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3725** sqlite3_finalize(S) returns the appropriate [error code] or 3726** [extended error code]. 3727** 3728** ^The sqlite3_finalize(S) routine can be called at any point during 3729** the life cycle of [prepared statement] S: 3730** before statement S is ever evaluated, after 3731** one or more calls to [sqlite3_reset()], or after any call 3732** to [sqlite3_step()] regardless of whether or not the statement has 3733** completed execution. 3734** 3735** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3736** 3737** The application must finalize every [prepared statement] in order to avoid 3738** resource leaks. It is a grievous error for the application to try to use 3739** a prepared statement after it has been finalized. Any use of a prepared 3740** statement after it has been finalized can result in undefined and 3741** undesirable behavior such as segfaults and heap corruption. 3742*/ 3743int sqlite3_finalize(sqlite3_stmt *pStmt); 3744 3745/* 3746** CAPI3REF: Reset A Prepared Statement Object 3747** 3748** The sqlite3_reset() function is called to reset a [prepared statement] 3749** object back to its initial state, ready to be re-executed. 3750** ^Any SQL statement variables that had values bound to them using 3751** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3752** Use [sqlite3_clear_bindings()] to reset the bindings. 3753** 3754** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3755** back to the beginning of its program. 3756** 3757** ^If the most recent call to [sqlite3_step(S)] for the 3758** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3759** or if [sqlite3_step(S)] has never before been called on S, 3760** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3761** 3762** ^If the most recent call to [sqlite3_step(S)] for the 3763** [prepared statement] S indicated an error, then 3764** [sqlite3_reset(S)] returns an appropriate [error code]. 3765** 3766** ^The [sqlite3_reset(S)] interface does not change the values 3767** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3768*/ 3769int sqlite3_reset(sqlite3_stmt *pStmt); 3770 3771/* 3772** CAPI3REF: Create Or Redefine SQL Functions 3773** KEYWORDS: {function creation routines} 3774** KEYWORDS: {application-defined SQL function} 3775** KEYWORDS: {application-defined SQL functions} 3776** 3777** ^These functions (collectively known as "function creation routines") 3778** are used to add SQL functions or aggregates or to redefine the behavior 3779** of existing SQL functions or aggregates. The only differences between 3780** these routines are the text encoding expected for 3781** the second parameter (the name of the function being created) 3782** and the presence or absence of a destructor callback for 3783** the application data pointer. 3784** 3785** ^The first parameter is the [database connection] to which the SQL 3786** function is to be added. ^If an application uses more than one database 3787** connection then application-defined SQL functions must be added 3788** to each database connection separately. 3789** 3790** ^The second parameter is the name of the SQL function to be created or 3791** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3792** representation, exclusive of the zero-terminator. ^Note that the name 3793** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3794** ^Any attempt to create a function with a longer name 3795** will result in [SQLITE_MISUSE] being returned. 3796** 3797** ^The third parameter (nArg) 3798** is the number of arguments that the SQL function or 3799** aggregate takes. ^If this parameter is -1, then the SQL function or 3800** aggregate may take any number of arguments between 0 and the limit 3801** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3802** parameter is less than -1 or greater than 127 then the behavior is 3803** undefined. 3804** 3805** ^The fourth parameter, eTextRep, specifies what 3806** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3807** its parameters. Every SQL function implementation must be able to work 3808** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3809** more efficient with one encoding than another. ^An application may 3810** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3811** times with the same function but with different values of eTextRep. 3812** ^When multiple implementations of the same function are available, SQLite 3813** will pick the one that involves the least amount of data conversion. 3814** If there is only a single implementation which does not care what text 3815** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3816** 3817** ^(The fifth parameter is an arbitrary pointer. The implementation of the 3818** function can gain access to this pointer using [sqlite3_user_data()].)^ 3819** 3820** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 3821** pointers to C-language functions that implement the SQL function or 3822** aggregate. ^A scalar SQL function requires an implementation of the xFunc 3823** callback only; NULL pointers must be passed as the xStep and xFinal 3824** parameters. ^An aggregate SQL function requires an implementation of xStep 3825** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 3826** SQL function or aggregate, pass NULL pointers for all three function 3827** callbacks. 3828** 3829** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 3830** then it is destructor for the application data pointer. 3831** The destructor is invoked when the function is deleted, either by being 3832** overloaded or when the database connection closes.)^ 3833** ^The destructor is also invoked if the call to 3834** sqlite3_create_function_v2() fails. 3835** ^When the destructor callback of the tenth parameter is invoked, it 3836** is passed a single argument which is a copy of the application data 3837** pointer which was the fifth parameter to sqlite3_create_function_v2(). 3838** 3839** ^It is permitted to register multiple implementations of the same 3840** functions with the same name but with either differing numbers of 3841** arguments or differing preferred text encodings. ^SQLite will use 3842** the implementation that most closely matches the way in which the 3843** SQL function is used. ^A function implementation with a non-negative 3844** nArg parameter is a better match than a function implementation with 3845** a negative nArg. ^A function where the preferred text encoding 3846** matches the database encoding is a better 3847** match than a function where the encoding is different. 3848** ^A function where the encoding difference is between UTF16le and UTF16be 3849** is a closer match than a function where the encoding difference is 3850** between UTF8 and UTF16. 3851** 3852** ^Built-in functions may be overloaded by new application-defined functions. 3853** 3854** ^An application-defined function is permitted to call other 3855** SQLite interfaces. However, such calls must not 3856** close the database connection nor finalize or reset the prepared 3857** statement in which the function is running. 3858*/ 3859int sqlite3_create_function( 3860 sqlite3 *db, 3861 const char *zFunctionName, 3862 int nArg, 3863 int eTextRep, 3864 void *pApp, 3865 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3866 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3867 void (*xFinal)(sqlite3_context*) 3868); 3869int sqlite3_create_function16( 3870 sqlite3 *db, 3871 const void *zFunctionName, 3872 int nArg, 3873 int eTextRep, 3874 void *pApp, 3875 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3876 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3877 void (*xFinal)(sqlite3_context*) 3878); 3879int sqlite3_create_function_v2( 3880 sqlite3 *db, 3881 const char *zFunctionName, 3882 int nArg, 3883 int eTextRep, 3884 void *pApp, 3885 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3886 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3887 void (*xFinal)(sqlite3_context*), 3888 void(*xDestroy)(void*) 3889); 3890 3891/* 3892** CAPI3REF: Text Encodings 3893** 3894** These constant define integer codes that represent the various 3895** text encodings supported by SQLite. 3896*/ 3897#define SQLITE_UTF8 1 3898#define SQLITE_UTF16LE 2 3899#define SQLITE_UTF16BE 3 3900#define SQLITE_UTF16 4 /* Use native byte order */ 3901#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3902#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3903 3904/* 3905** CAPI3REF: Deprecated Functions 3906** DEPRECATED 3907** 3908** These functions are [deprecated]. In order to maintain 3909** backwards compatibility with older code, these functions continue 3910** to be supported. However, new applications should avoid 3911** the use of these functions. To help encourage people to avoid 3912** using these functions, we are not going to tell you what they do. 3913*/ 3914#ifndef SQLITE_OMIT_DEPRECATED 3915SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3916SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3917SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3918SQLITE_DEPRECATED int sqlite3_global_recover(void); 3919SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3920SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3921#endif 3922 3923/* 3924** CAPI3REF: Obtaining SQL Function Parameter Values 3925** 3926** The C-language implementation of SQL functions and aggregates uses 3927** this set of interface routines to access the parameter values on 3928** the function or aggregate. 3929** 3930** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3931** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3932** define callbacks that implement the SQL functions and aggregates. 3933** The 3rd parameter to these callbacks is an array of pointers to 3934** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3935** each parameter to the SQL function. These routines are used to 3936** extract values from the [sqlite3_value] objects. 3937** 3938** These routines work only with [protected sqlite3_value] objects. 3939** Any attempt to use these routines on an [unprotected sqlite3_value] 3940** object results in undefined behavior. 3941** 3942** ^These routines work just like the corresponding [column access functions] 3943** except that these routines take a single [protected sqlite3_value] object 3944** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3945** 3946** ^The sqlite3_value_text16() interface extracts a UTF-16 string 3947** in the native byte-order of the host machine. ^The 3948** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3949** extract UTF-16 strings as big-endian and little-endian respectively. 3950** 3951** ^(The sqlite3_value_numeric_type() interface attempts to apply 3952** numeric affinity to the value. This means that an attempt is 3953** made to convert the value to an integer or floating point. If 3954** such a conversion is possible without loss of information (in other 3955** words, if the value is a string that looks like a number) 3956** then the conversion is performed. Otherwise no conversion occurs. 3957** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 3958** 3959** Please pay particular attention to the fact that the pointer returned 3960** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3961** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3962** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3963** or [sqlite3_value_text16()]. 3964** 3965** These routines must be called from the same thread as 3966** the SQL function that supplied the [sqlite3_value*] parameters. 3967*/ 3968const void *sqlite3_value_blob(sqlite3_value*); 3969int sqlite3_value_bytes(sqlite3_value*); 3970int sqlite3_value_bytes16(sqlite3_value*); 3971double sqlite3_value_double(sqlite3_value*); 3972int sqlite3_value_int(sqlite3_value*); 3973sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3974const unsigned char *sqlite3_value_text(sqlite3_value*); 3975const void *sqlite3_value_text16(sqlite3_value*); 3976const void *sqlite3_value_text16le(sqlite3_value*); 3977const void *sqlite3_value_text16be(sqlite3_value*); 3978int sqlite3_value_type(sqlite3_value*); 3979int sqlite3_value_numeric_type(sqlite3_value*); 3980 3981/* 3982** CAPI3REF: Obtain Aggregate Function Context 3983** 3984** Implementations of aggregate SQL functions use this 3985** routine to allocate memory for storing their state. 3986** 3987** ^The first time the sqlite3_aggregate_context(C,N) routine is called 3988** for a particular aggregate function, SQLite 3989** allocates N of memory, zeroes out that memory, and returns a pointer 3990** to the new memory. ^On second and subsequent calls to 3991** sqlite3_aggregate_context() for the same aggregate function instance, 3992** the same buffer is returned. Sqlite3_aggregate_context() is normally 3993** called once for each invocation of the xStep callback and then one 3994** last time when the xFinal callback is invoked. ^(When no rows match 3995** an aggregate query, the xStep() callback of the aggregate function 3996** implementation is never called and xFinal() is called exactly once. 3997** In those cases, sqlite3_aggregate_context() might be called for the 3998** first time from within xFinal().)^ 3999** 4000** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is 4001** less than or equal to zero or if a memory allocate error occurs. 4002** 4003** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4004** determined by the N parameter on first successful call. Changing the 4005** value of N in subsequent call to sqlite3_aggregate_context() within 4006** the same aggregate function instance will not resize the memory 4007** allocation.)^ 4008** 4009** ^SQLite automatically frees the memory allocated by 4010** sqlite3_aggregate_context() when the aggregate query concludes. 4011** 4012** The first parameter must be a copy of the 4013** [sqlite3_context | SQL function context] that is the first parameter 4014** to the xStep or xFinal callback routine that implements the aggregate 4015** function. 4016** 4017** This routine must be called from the same thread in which 4018** the aggregate SQL function is running. 4019*/ 4020void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4021 4022/* 4023** CAPI3REF: User Data For Functions 4024** 4025** ^The sqlite3_user_data() interface returns a copy of 4026** the pointer that was the pUserData parameter (the 5th parameter) 4027** of the [sqlite3_create_function()] 4028** and [sqlite3_create_function16()] routines that originally 4029** registered the application defined function. 4030** 4031** This routine must be called from the same thread in which 4032** the application-defined function is running. 4033*/ 4034void *sqlite3_user_data(sqlite3_context*); 4035 4036/* 4037** CAPI3REF: Database Connection For Functions 4038** 4039** ^The sqlite3_context_db_handle() interface returns a copy of 4040** the pointer to the [database connection] (the 1st parameter) 4041** of the [sqlite3_create_function()] 4042** and [sqlite3_create_function16()] routines that originally 4043** registered the application defined function. 4044*/ 4045sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4046 4047/* 4048** CAPI3REF: Function Auxiliary Data 4049** 4050** The following two functions may be used by scalar SQL functions to 4051** associate metadata with argument values. If the same value is passed to 4052** multiple invocations of the same SQL function during query execution, under 4053** some circumstances the associated metadata may be preserved. This may 4054** be used, for example, to add a regular-expression matching scalar 4055** function. The compiled version of the regular expression is stored as 4056** metadata associated with the SQL value passed as the regular expression 4057** pattern. The compiled regular expression can be reused on multiple 4058** invocations of the same function so that the original pattern string 4059** does not need to be recompiled on each invocation. 4060** 4061** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4062** associated by the sqlite3_set_auxdata() function with the Nth argument 4063** value to the application-defined function. ^If no metadata has been ever 4064** been set for the Nth argument of the function, or if the corresponding 4065** function parameter has changed since the meta-data was set, 4066** then sqlite3_get_auxdata() returns a NULL pointer. 4067** 4068** ^The sqlite3_set_auxdata() interface saves the metadata 4069** pointed to by its 3rd parameter as the metadata for the N-th 4070** argument of the application-defined function. Subsequent 4071** calls to sqlite3_get_auxdata() might return this data, if it has 4072** not been destroyed. 4073** ^If it is not NULL, SQLite will invoke the destructor 4074** function given by the 4th parameter to sqlite3_set_auxdata() on 4075** the metadata when the corresponding function parameter changes 4076** or when the SQL statement completes, whichever comes first. 4077** 4078** SQLite is free to call the destructor and drop metadata on any 4079** parameter of any function at any time. ^The only guarantee is that 4080** the destructor will be called before the metadata is dropped. 4081** 4082** ^(In practice, metadata is preserved between function calls for 4083** expressions that are constant at compile time. This includes literal 4084** values and [parameters].)^ 4085** 4086** These routines must be called from the same thread in which 4087** the SQL function is running. 4088*/ 4089void *sqlite3_get_auxdata(sqlite3_context*, int N); 4090void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4091 4092 4093/* 4094** CAPI3REF: Constants Defining Special Destructor Behavior 4095** 4096** These are special values for the destructor that is passed in as the 4097** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4098** argument is SQLITE_STATIC, it means that the content pointer is constant 4099** and will never change. It does not need to be destroyed. ^The 4100** SQLITE_TRANSIENT value means that the content will likely change in 4101** the near future and that SQLite should make its own private copy of 4102** the content before returning. 4103** 4104** The typedef is necessary to work around problems in certain 4105** C++ compilers. See ticket #2191. 4106*/ 4107typedef void (*sqlite3_destructor_type)(void*); 4108#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4109#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4110 4111/* 4112** CAPI3REF: Setting The Result Of An SQL Function 4113** 4114** These routines are used by the xFunc or xFinal callbacks that 4115** implement SQL functions and aggregates. See 4116** [sqlite3_create_function()] and [sqlite3_create_function16()] 4117** for additional information. 4118** 4119** These functions work very much like the [parameter binding] family of 4120** functions used to bind values to host parameters in prepared statements. 4121** Refer to the [SQL parameter] documentation for additional information. 4122** 4123** ^The sqlite3_result_blob() interface sets the result from 4124** an application-defined function to be the BLOB whose content is pointed 4125** to by the second parameter and which is N bytes long where N is the 4126** third parameter. 4127** 4128** ^The sqlite3_result_zeroblob() interfaces set the result of 4129** the application-defined function to be a BLOB containing all zero 4130** bytes and N bytes in size, where N is the value of the 2nd parameter. 4131** 4132** ^The sqlite3_result_double() interface sets the result from 4133** an application-defined function to be a floating point value specified 4134** by its 2nd argument. 4135** 4136** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4137** cause the implemented SQL function to throw an exception. 4138** ^SQLite uses the string pointed to by the 4139** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4140** as the text of an error message. ^SQLite interprets the error 4141** message string from sqlite3_result_error() as UTF-8. ^SQLite 4142** interprets the string from sqlite3_result_error16() as UTF-16 in native 4143** byte order. ^If the third parameter to sqlite3_result_error() 4144** or sqlite3_result_error16() is negative then SQLite takes as the error 4145** message all text up through the first zero character. 4146** ^If the third parameter to sqlite3_result_error() or 4147** sqlite3_result_error16() is non-negative then SQLite takes that many 4148** bytes (not characters) from the 2nd parameter as the error message. 4149** ^The sqlite3_result_error() and sqlite3_result_error16() 4150** routines make a private copy of the error message text before 4151** they return. Hence, the calling function can deallocate or 4152** modify the text after they return without harm. 4153** ^The sqlite3_result_error_code() function changes the error code 4154** returned by SQLite as a result of an error in a function. ^By default, 4155** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4156** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4157** 4158** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4159** error indicating that a string or BLOB is too long to represent. 4160** 4161** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4162** error indicating that a memory allocation failed. 4163** 4164** ^The sqlite3_result_int() interface sets the return value 4165** of the application-defined function to be the 32-bit signed integer 4166** value given in the 2nd argument. 4167** ^The sqlite3_result_int64() interface sets the return value 4168** of the application-defined function to be the 64-bit signed integer 4169** value given in the 2nd argument. 4170** 4171** ^The sqlite3_result_null() interface sets the return value 4172** of the application-defined function to be NULL. 4173** 4174** ^The sqlite3_result_text(), sqlite3_result_text16(), 4175** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4176** set the return value of the application-defined function to be 4177** a text string which is represented as UTF-8, UTF-16 native byte order, 4178** UTF-16 little endian, or UTF-16 big endian, respectively. 4179** ^SQLite takes the text result from the application from 4180** the 2nd parameter of the sqlite3_result_text* interfaces. 4181** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4182** is negative, then SQLite takes result text from the 2nd parameter 4183** through the first zero character. 4184** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4185** is non-negative, then as many bytes (not characters) of the text 4186** pointed to by the 2nd parameter are taken as the application-defined 4187** function result. If the 3rd parameter is non-negative, then it 4188** must be the byte offset into the string where the NUL terminator would 4189** appear if the string where NUL terminated. If any NUL characters occur 4190** in the string at a byte offset that is less than the value of the 3rd 4191** parameter, then the resulting string will contain embedded NULs and the 4192** result of expressions operating on strings with embedded NULs is undefined. 4193** ^If the 4th parameter to the sqlite3_result_text* interfaces 4194** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4195** function as the destructor on the text or BLOB result when it has 4196** finished using that result. 4197** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4198** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4199** assumes that the text or BLOB result is in constant space and does not 4200** copy the content of the parameter nor call a destructor on the content 4201** when it has finished using that result. 4202** ^If the 4th parameter to the sqlite3_result_text* interfaces 4203** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4204** then SQLite makes a copy of the result into space obtained from 4205** from [sqlite3_malloc()] before it returns. 4206** 4207** ^The sqlite3_result_value() interface sets the result of 4208** the application-defined function to be a copy the 4209** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4210** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4211** so that the [sqlite3_value] specified in the parameter may change or 4212** be deallocated after sqlite3_result_value() returns without harm. 4213** ^A [protected sqlite3_value] object may always be used where an 4214** [unprotected sqlite3_value] object is required, so either 4215** kind of [sqlite3_value] object can be used with this interface. 4216** 4217** If these routines are called from within the different thread 4218** than the one containing the application-defined function that received 4219** the [sqlite3_context] pointer, the results are undefined. 4220*/ 4221void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4222void sqlite3_result_double(sqlite3_context*, double); 4223void sqlite3_result_error(sqlite3_context*, const char*, int); 4224void sqlite3_result_error16(sqlite3_context*, const void*, int); 4225void sqlite3_result_error_toobig(sqlite3_context*); 4226void sqlite3_result_error_nomem(sqlite3_context*); 4227void sqlite3_result_error_code(sqlite3_context*, int); 4228void sqlite3_result_int(sqlite3_context*, int); 4229void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4230void sqlite3_result_null(sqlite3_context*); 4231void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4232void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4233void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4234void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4235void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4236void sqlite3_result_zeroblob(sqlite3_context*, int n); 4237 4238/* 4239** CAPI3REF: Define New Collating Sequences 4240** 4241** ^These functions add, remove, or modify a [collation] associated 4242** with the [database connection] specified as the first argument. 4243** 4244** ^The name of the collation is a UTF-8 string 4245** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4246** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4247** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4248** considered to be the same name. 4249** 4250** ^(The third argument (eTextRep) must be one of the constants: 4251** <ul> 4252** <li> [SQLITE_UTF8], 4253** <li> [SQLITE_UTF16LE], 4254** <li> [SQLITE_UTF16BE], 4255** <li> [SQLITE_UTF16], or 4256** <li> [SQLITE_UTF16_ALIGNED]. 4257** </ul>)^ 4258** ^The eTextRep argument determines the encoding of strings passed 4259** to the collating function callback, xCallback. 4260** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4261** force strings to be UTF16 with native byte order. 4262** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4263** on an even byte address. 4264** 4265** ^The fourth argument, pArg, is an application data pointer that is passed 4266** through as the first argument to the collating function callback. 4267** 4268** ^The fifth argument, xCallback, is a pointer to the collating function. 4269** ^Multiple collating functions can be registered using the same name but 4270** with different eTextRep parameters and SQLite will use whichever 4271** function requires the least amount of data transformation. 4272** ^If the xCallback argument is NULL then the collating function is 4273** deleted. ^When all collating functions having the same name are deleted, 4274** that collation is no longer usable. 4275** 4276** ^The collating function callback is invoked with a copy of the pArg 4277** application data pointer and with two strings in the encoding specified 4278** by the eTextRep argument. The collating function must return an 4279** integer that is negative, zero, or positive 4280** if the first string is less than, equal to, or greater than the second, 4281** respectively. A collating function must always return the same answer 4282** given the same inputs. If two or more collating functions are registered 4283** to the same collation name (using different eTextRep values) then all 4284** must give an equivalent answer when invoked with equivalent strings. 4285** The collating function must obey the following properties for all 4286** strings A, B, and C: 4287** 4288** <ol> 4289** <li> If A==B then B==A. 4290** <li> If A==B and B==C then A==C. 4291** <li> If A<B THEN B>A. 4292** <li> If A<B and B<C then A<C. 4293** </ol> 4294** 4295** If a collating function fails any of the above constraints and that 4296** collating function is registered and used, then the behavior of SQLite 4297** is undefined. 4298** 4299** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4300** with the addition that the xDestroy callback is invoked on pArg when 4301** the collating function is deleted. 4302** ^Collating functions are deleted when they are overridden by later 4303** calls to the collation creation functions or when the 4304** [database connection] is closed using [sqlite3_close()]. 4305** 4306** ^The xDestroy callback is <u>not</u> called if the 4307** sqlite3_create_collation_v2() function fails. Applications that invoke 4308** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4309** check the return code and dispose of the application data pointer 4310** themselves rather than expecting SQLite to deal with it for them. 4311** This is different from every other SQLite interface. The inconsistency 4312** is unfortunate but cannot be changed without breaking backwards 4313** compatibility. 4314** 4315** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4316*/ 4317int sqlite3_create_collation( 4318 sqlite3*, 4319 const char *zName, 4320 int eTextRep, 4321 void *pArg, 4322 int(*xCompare)(void*,int,const void*,int,const void*) 4323); 4324int sqlite3_create_collation_v2( 4325 sqlite3*, 4326 const char *zName, 4327 int eTextRep, 4328 void *pArg, 4329 int(*xCompare)(void*,int,const void*,int,const void*), 4330 void(*xDestroy)(void*) 4331); 4332int sqlite3_create_collation16( 4333 sqlite3*, 4334 const void *zName, 4335 int eTextRep, 4336 void *pArg, 4337 int(*xCompare)(void*,int,const void*,int,const void*) 4338); 4339 4340/* 4341** CAPI3REF: Collation Needed Callbacks 4342** 4343** ^To avoid having to register all collation sequences before a database 4344** can be used, a single callback function may be registered with the 4345** [database connection] to be invoked whenever an undefined collation 4346** sequence is required. 4347** 4348** ^If the function is registered using the sqlite3_collation_needed() API, 4349** then it is passed the names of undefined collation sequences as strings 4350** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4351** the names are passed as UTF-16 in machine native byte order. 4352** ^A call to either function replaces the existing collation-needed callback. 4353** 4354** ^(When the callback is invoked, the first argument passed is a copy 4355** of the second argument to sqlite3_collation_needed() or 4356** sqlite3_collation_needed16(). The second argument is the database 4357** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4358** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4359** sequence function required. The fourth parameter is the name of the 4360** required collation sequence.)^ 4361** 4362** The callback function should register the desired collation using 4363** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4364** [sqlite3_create_collation_v2()]. 4365*/ 4366int sqlite3_collation_needed( 4367 sqlite3*, 4368 void*, 4369 void(*)(void*,sqlite3*,int eTextRep,const char*) 4370); 4371int sqlite3_collation_needed16( 4372 sqlite3*, 4373 void*, 4374 void(*)(void*,sqlite3*,int eTextRep,const void*) 4375); 4376 4377#ifdef SQLITE_HAS_CODEC 4378/* 4379** Specify the key for an encrypted database. This routine should be 4380** called right after sqlite3_open(). 4381** 4382** The code to implement this API is not available in the public release 4383** of SQLite. 4384*/ 4385int sqlite3_key( 4386 sqlite3 *db, /* Database to be rekeyed */ 4387 const void *pKey, int nKey /* The key */ 4388); 4389 4390/* 4391** Change the key on an open database. If the current database is not 4392** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4393** database is decrypted. 4394** 4395** The code to implement this API is not available in the public release 4396** of SQLite. 4397*/ 4398int sqlite3_rekey( 4399 sqlite3 *db, /* Database to be rekeyed */ 4400 const void *pKey, int nKey /* The new key */ 4401); 4402 4403/* 4404** Specify the activation key for a SEE database. Unless 4405** activated, none of the SEE routines will work. 4406*/ 4407void sqlite3_activate_see( 4408 const char *zPassPhrase /* Activation phrase */ 4409); 4410#endif 4411 4412#ifdef SQLITE_ENABLE_CEROD 4413/* 4414** Specify the activation key for a CEROD database. Unless 4415** activated, none of the CEROD routines will work. 4416*/ 4417void sqlite3_activate_cerod( 4418 const char *zPassPhrase /* Activation phrase */ 4419); 4420#endif 4421 4422/* 4423** CAPI3REF: Suspend Execution For A Short Time 4424** 4425** The sqlite3_sleep() function causes the current thread to suspend execution 4426** for at least a number of milliseconds specified in its parameter. 4427** 4428** If the operating system does not support sleep requests with 4429** millisecond time resolution, then the time will be rounded up to 4430** the nearest second. The number of milliseconds of sleep actually 4431** requested from the operating system is returned. 4432** 4433** ^SQLite implements this interface by calling the xSleep() 4434** method of the default [sqlite3_vfs] object. If the xSleep() method 4435** of the default VFS is not implemented correctly, or not implemented at 4436** all, then the behavior of sqlite3_sleep() may deviate from the description 4437** in the previous paragraphs. 4438*/ 4439int sqlite3_sleep(int); 4440 4441/* 4442** CAPI3REF: Name Of The Folder Holding Temporary Files 4443** 4444** ^(If this global variable is made to point to a string which is 4445** the name of a folder (a.k.a. directory), then all temporary files 4446** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4447** will be placed in that directory.)^ ^If this variable 4448** is a NULL pointer, then SQLite performs a search for an appropriate 4449** temporary file directory. 4450** 4451** It is not safe to read or modify this variable in more than one 4452** thread at a time. It is not safe to read or modify this variable 4453** if a [database connection] is being used at the same time in a separate 4454** thread. 4455** It is intended that this variable be set once 4456** as part of process initialization and before any SQLite interface 4457** routines have been called and that this variable remain unchanged 4458** thereafter. 4459** 4460** ^The [temp_store_directory pragma] may modify this variable and cause 4461** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4462** the [temp_store_directory pragma] always assumes that any string 4463** that this variable points to is held in memory obtained from 4464** [sqlite3_malloc] and the pragma may attempt to free that memory 4465** using [sqlite3_free]. 4466** Hence, if this variable is modified directly, either it should be 4467** made NULL or made to point to memory obtained from [sqlite3_malloc] 4468** or else the use of the [temp_store_directory pragma] should be avoided. 4469*/ 4470SQLITE_EXTERN char *sqlite3_temp_directory; 4471 4472/* 4473** CAPI3REF: Name Of The Folder Holding Database Files 4474** 4475** ^(If this global variable is made to point to a string which is 4476** the name of a folder (a.k.a. directory), then all database files 4477** specified with a relative pathname and created or accessed by 4478** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4479** to be relative to that directory.)^ ^If this variable is a NULL 4480** pointer, then SQLite assumes that all database files specified 4481** with a relative pathname are relative to the current directory 4482** for the process. Only the windows VFS makes use of this global 4483** variable; it is ignored by the unix VFS. 4484** 4485** Changing the value of this variable while a database connection is 4486** open can result in a corrupt database. 4487** 4488** It is not safe to read or modify this variable in more than one 4489** thread at a time. It is not safe to read or modify this variable 4490** if a [database connection] is being used at the same time in a separate 4491** thread. 4492** It is intended that this variable be set once 4493** as part of process initialization and before any SQLite interface 4494** routines have been called and that this variable remain unchanged 4495** thereafter. 4496** 4497** ^The [data_store_directory pragma] may modify this variable and cause 4498** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4499** the [data_store_directory pragma] always assumes that any string 4500** that this variable points to is held in memory obtained from 4501** [sqlite3_malloc] and the pragma may attempt to free that memory 4502** using [sqlite3_free]. 4503** Hence, if this variable is modified directly, either it should be 4504** made NULL or made to point to memory obtained from [sqlite3_malloc] 4505** or else the use of the [data_store_directory pragma] should be avoided. 4506*/ 4507SQLITE_EXTERN char *sqlite3_data_directory; 4508 4509/* 4510** CAPI3REF: Test For Auto-Commit Mode 4511** KEYWORDS: {autocommit mode} 4512** 4513** ^The sqlite3_get_autocommit() interface returns non-zero or 4514** zero if the given database connection is or is not in autocommit mode, 4515** respectively. ^Autocommit mode is on by default. 4516** ^Autocommit mode is disabled by a [BEGIN] statement. 4517** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4518** 4519** If certain kinds of errors occur on a statement within a multi-statement 4520** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4521** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4522** transaction might be rolled back automatically. The only way to 4523** find out whether SQLite automatically rolled back the transaction after 4524** an error is to use this function. 4525** 4526** If another thread changes the autocommit status of the database 4527** connection while this routine is running, then the return value 4528** is undefined. 4529*/ 4530int sqlite3_get_autocommit(sqlite3*); 4531 4532/* 4533** CAPI3REF: Find The Database Handle Of A Prepared Statement 4534** 4535** ^The sqlite3_db_handle interface returns the [database connection] handle 4536** to which a [prepared statement] belongs. ^The [database connection] 4537** returned by sqlite3_db_handle is the same [database connection] 4538** that was the first argument 4539** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4540** create the statement in the first place. 4541*/ 4542sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4543 4544/* 4545** CAPI3REF: Return The Filename For A Database Connection 4546** 4547** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4548** associated with database N of connection D. ^The main database file 4549** has the name "main". If there is no attached database N on the database 4550** connection D, or if database N is a temporary or in-memory database, then 4551** a NULL pointer is returned. 4552** 4553** ^The filename returned by this function is the output of the 4554** xFullPathname method of the [VFS]. ^In other words, the filename 4555** will be an absolute pathname, even if the filename used 4556** to open the database originally was a URI or relative pathname. 4557*/ 4558const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4559 4560/* 4561** CAPI3REF: Determine if a database is read-only 4562** 4563** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4564** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4565** the name of a database on connection D. 4566*/ 4567int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4568 4569/* 4570** CAPI3REF: Find the next prepared statement 4571** 4572** ^This interface returns a pointer to the next [prepared statement] after 4573** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4574** then this interface returns a pointer to the first prepared statement 4575** associated with the database connection pDb. ^If no prepared statement 4576** satisfies the conditions of this routine, it returns NULL. 4577** 4578** The [database connection] pointer D in a call to 4579** [sqlite3_next_stmt(D,S)] must refer to an open database 4580** connection and in particular must not be a NULL pointer. 4581*/ 4582sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4583 4584/* 4585** CAPI3REF: Commit And Rollback Notification Callbacks 4586** 4587** ^The sqlite3_commit_hook() interface registers a callback 4588** function to be invoked whenever a transaction is [COMMIT | committed]. 4589** ^Any callback set by a previous call to sqlite3_commit_hook() 4590** for the same database connection is overridden. 4591** ^The sqlite3_rollback_hook() interface registers a callback 4592** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4593** ^Any callback set by a previous call to sqlite3_rollback_hook() 4594** for the same database connection is overridden. 4595** ^The pArg argument is passed through to the callback. 4596** ^If the callback on a commit hook function returns non-zero, 4597** then the commit is converted into a rollback. 4598** 4599** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4600** return the P argument from the previous call of the same function 4601** on the same [database connection] D, or NULL for 4602** the first call for each function on D. 4603** 4604** The commit and rollback hook callbacks are not reentrant. 4605** The callback implementation must not do anything that will modify 4606** the database connection that invoked the callback. Any actions 4607** to modify the database connection must be deferred until after the 4608** completion of the [sqlite3_step()] call that triggered the commit 4609** or rollback hook in the first place. 4610** Note that running any other SQL statements, including SELECT statements, 4611** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4612** the database connections for the meaning of "modify" in this paragraph. 4613** 4614** ^Registering a NULL function disables the callback. 4615** 4616** ^When the commit hook callback routine returns zero, the [COMMIT] 4617** operation is allowed to continue normally. ^If the commit hook 4618** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4619** ^The rollback hook is invoked on a rollback that results from a commit 4620** hook returning non-zero, just as it would be with any other rollback. 4621** 4622** ^For the purposes of this API, a transaction is said to have been 4623** rolled back if an explicit "ROLLBACK" statement is executed, or 4624** an error or constraint causes an implicit rollback to occur. 4625** ^The rollback callback is not invoked if a transaction is 4626** automatically rolled back because the database connection is closed. 4627** 4628** See also the [sqlite3_update_hook()] interface. 4629*/ 4630void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4631void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4632 4633/* 4634** CAPI3REF: Data Change Notification Callbacks 4635** 4636** ^The sqlite3_update_hook() interface registers a callback function 4637** with the [database connection] identified by the first argument 4638** to be invoked whenever a row is updated, inserted or deleted. 4639** ^Any callback set by a previous call to this function 4640** for the same database connection is overridden. 4641** 4642** ^The second argument is a pointer to the function to invoke when a 4643** row is updated, inserted or deleted. 4644** ^The first argument to the callback is a copy of the third argument 4645** to sqlite3_update_hook(). 4646** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4647** or [SQLITE_UPDATE], depending on the operation that caused the callback 4648** to be invoked. 4649** ^The third and fourth arguments to the callback contain pointers to the 4650** database and table name containing the affected row. 4651** ^The final callback parameter is the [rowid] of the row. 4652** ^In the case of an update, this is the [rowid] after the update takes place. 4653** 4654** ^(The update hook is not invoked when internal system tables are 4655** modified (i.e. sqlite_master and sqlite_sequence).)^ 4656** 4657** ^In the current implementation, the update hook 4658** is not invoked when duplication rows are deleted because of an 4659** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4660** invoked when rows are deleted using the [truncate optimization]. 4661** The exceptions defined in this paragraph might change in a future 4662** release of SQLite. 4663** 4664** The update hook implementation must not do anything that will modify 4665** the database connection that invoked the update hook. Any actions 4666** to modify the database connection must be deferred until after the 4667** completion of the [sqlite3_step()] call that triggered the update hook. 4668** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4669** database connections for the meaning of "modify" in this paragraph. 4670** 4671** ^The sqlite3_update_hook(D,C,P) function 4672** returns the P argument from the previous call 4673** on the same [database connection] D, or NULL for 4674** the first call on D. 4675** 4676** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4677** interfaces. 4678*/ 4679void *sqlite3_update_hook( 4680 sqlite3*, 4681 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4682 void* 4683); 4684 4685/* 4686** CAPI3REF: Enable Or Disable Shared Pager Cache 4687** 4688** ^(This routine enables or disables the sharing of the database cache 4689** and schema data structures between [database connection | connections] 4690** to the same database. Sharing is enabled if the argument is true 4691** and disabled if the argument is false.)^ 4692** 4693** ^Cache sharing is enabled and disabled for an entire process. 4694** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4695** sharing was enabled or disabled for each thread separately. 4696** 4697** ^(The cache sharing mode set by this interface effects all subsequent 4698** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4699** Existing database connections continue use the sharing mode 4700** that was in effect at the time they were opened.)^ 4701** 4702** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4703** successfully. An [error code] is returned otherwise.)^ 4704** 4705** ^Shared cache is disabled by default. But this might change in 4706** future releases of SQLite. Applications that care about shared 4707** cache setting should set it explicitly. 4708** 4709** See Also: [SQLite Shared-Cache Mode] 4710*/ 4711int sqlite3_enable_shared_cache(int); 4712 4713/* 4714** CAPI3REF: Attempt To Free Heap Memory 4715** 4716** ^The sqlite3_release_memory() interface attempts to free N bytes 4717** of heap memory by deallocating non-essential memory allocations 4718** held by the database library. Memory used to cache database 4719** pages to improve performance is an example of non-essential memory. 4720** ^sqlite3_release_memory() returns the number of bytes actually freed, 4721** which might be more or less than the amount requested. 4722** ^The sqlite3_release_memory() routine is a no-op returning zero 4723** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4724** 4725** See also: [sqlite3_db_release_memory()] 4726*/ 4727int sqlite3_release_memory(int); 4728 4729/* 4730** CAPI3REF: Free Memory Used By A Database Connection 4731** 4732** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 4733** memory as possible from database connection D. Unlike the 4734** [sqlite3_release_memory()] interface, this interface is effect even 4735** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 4736** omitted. 4737** 4738** See also: [sqlite3_release_memory()] 4739*/ 4740int sqlite3_db_release_memory(sqlite3*); 4741 4742/* 4743** CAPI3REF: Impose A Limit On Heap Size 4744** 4745** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4746** soft limit on the amount of heap memory that may be allocated by SQLite. 4747** ^SQLite strives to keep heap memory utilization below the soft heap 4748** limit by reducing the number of pages held in the page cache 4749** as heap memory usages approaches the limit. 4750** ^The soft heap limit is "soft" because even though SQLite strives to stay 4751** below the limit, it will exceed the limit rather than generate 4752** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4753** is advisory only. 4754** 4755** ^The return value from sqlite3_soft_heap_limit64() is the size of 4756** the soft heap limit prior to the call, or negative in the case of an 4757** error. ^If the argument N is negative 4758** then no change is made to the soft heap limit. Hence, the current 4759** size of the soft heap limit can be determined by invoking 4760** sqlite3_soft_heap_limit64() with a negative argument. 4761** 4762** ^If the argument N is zero then the soft heap limit is disabled. 4763** 4764** ^(The soft heap limit is not enforced in the current implementation 4765** if one or more of following conditions are true: 4766** 4767** <ul> 4768** <li> The soft heap limit is set to zero. 4769** <li> Memory accounting is disabled using a combination of the 4770** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 4771** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 4772** <li> An alternative page cache implementation is specified using 4773** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 4774** <li> The page cache allocates from its own memory pool supplied 4775** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 4776** from the heap. 4777** </ul>)^ 4778** 4779** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 4780** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 4781** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 4782** the soft heap limit is enforced on every memory allocation. Without 4783** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 4784** when memory is allocated by the page cache. Testing suggests that because 4785** the page cache is the predominate memory user in SQLite, most 4786** applications will achieve adequate soft heap limit enforcement without 4787** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4788** 4789** The circumstances under which SQLite will enforce the soft heap limit may 4790** changes in future releases of SQLite. 4791*/ 4792sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 4793 4794/* 4795** CAPI3REF: Deprecated Soft Heap Limit Interface 4796** DEPRECATED 4797** 4798** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 4799** interface. This routine is provided for historical compatibility 4800** only. All new applications should use the 4801** [sqlite3_soft_heap_limit64()] interface rather than this one. 4802*/ 4803SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 4804 4805 4806/* 4807** CAPI3REF: Extract Metadata About A Column Of A Table 4808** 4809** ^This routine returns metadata about a specific column of a specific 4810** database table accessible using the [database connection] handle 4811** passed as the first function argument. 4812** 4813** ^The column is identified by the second, third and fourth parameters to 4814** this function. ^The second parameter is either the name of the database 4815** (i.e. "main", "temp", or an attached database) containing the specified 4816** table or NULL. ^If it is NULL, then all attached databases are searched 4817** for the table using the same algorithm used by the database engine to 4818** resolve unqualified table references. 4819** 4820** ^The third and fourth parameters to this function are the table and column 4821** name of the desired column, respectively. Neither of these parameters 4822** may be NULL. 4823** 4824** ^Metadata is returned by writing to the memory locations passed as the 5th 4825** and subsequent parameters to this function. ^Any of these arguments may be 4826** NULL, in which case the corresponding element of metadata is omitted. 4827** 4828** ^(<blockquote> 4829** <table border="1"> 4830** <tr><th> Parameter <th> Output<br>Type <th> Description 4831** 4832** <tr><td> 5th <td> const char* <td> Data type 4833** <tr><td> 6th <td> const char* <td> Name of default collation sequence 4834** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 4835** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 4836** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 4837** </table> 4838** </blockquote>)^ 4839** 4840** ^The memory pointed to by the character pointers returned for the 4841** declaration type and collation sequence is valid only until the next 4842** call to any SQLite API function. 4843** 4844** ^If the specified table is actually a view, an [error code] is returned. 4845** 4846** ^If the specified column is "rowid", "oid" or "_rowid_" and an 4847** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 4848** parameters are set for the explicitly declared column. ^(If there is no 4849** explicitly declared [INTEGER PRIMARY KEY] column, then the output 4850** parameters are set as follows: 4851** 4852** <pre> 4853** data type: "INTEGER" 4854** collation sequence: "BINARY" 4855** not null: 0 4856** primary key: 1 4857** auto increment: 0 4858** </pre>)^ 4859** 4860** ^(This function may load one or more schemas from database files. If an 4861** error occurs during this process, or if the requested table or column 4862** cannot be found, an [error code] is returned and an error message left 4863** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 4864** 4865** ^This API is only available if the library was compiled with the 4866** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 4867*/ 4868int sqlite3_table_column_metadata( 4869 sqlite3 *db, /* Connection handle */ 4870 const char *zDbName, /* Database name or NULL */ 4871 const char *zTableName, /* Table name */ 4872 const char *zColumnName, /* Column name */ 4873 char const **pzDataType, /* OUTPUT: Declared data type */ 4874 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4875 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4876 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4877 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4878); 4879 4880/* 4881** CAPI3REF: Load An Extension 4882** 4883** ^This interface loads an SQLite extension library from the named file. 4884** 4885** ^The sqlite3_load_extension() interface attempts to load an 4886** SQLite extension library contained in the file zFile. 4887** 4888** ^The entry point is zProc. 4889** ^zProc may be 0, in which case the name of the entry point 4890** defaults to "sqlite3_extension_init". 4891** ^The sqlite3_load_extension() interface returns 4892** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4893** ^If an error occurs and pzErrMsg is not 0, then the 4894** [sqlite3_load_extension()] interface shall attempt to 4895** fill *pzErrMsg with error message text stored in memory 4896** obtained from [sqlite3_malloc()]. The calling function 4897** should free this memory by calling [sqlite3_free()]. 4898** 4899** ^Extension loading must be enabled using 4900** [sqlite3_enable_load_extension()] prior to calling this API, 4901** otherwise an error will be returned. 4902** 4903** See also the [load_extension() SQL function]. 4904*/ 4905int sqlite3_load_extension( 4906 sqlite3 *db, /* Load the extension into this database connection */ 4907 const char *zFile, /* Name of the shared library containing extension */ 4908 const char *zProc, /* Entry point. Derived from zFile if 0 */ 4909 char **pzErrMsg /* Put error message here if not 0 */ 4910); 4911 4912/* 4913** CAPI3REF: Enable Or Disable Extension Loading 4914** 4915** ^So as not to open security holes in older applications that are 4916** unprepared to deal with extension loading, and as a means of disabling 4917** extension loading while evaluating user-entered SQL, the following API 4918** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 4919** 4920** ^Extension loading is off by default. See ticket #1863. 4921** ^Call the sqlite3_enable_load_extension() routine with onoff==1 4922** to turn extension loading on and call it with onoff==0 to turn 4923** it back off again. 4924*/ 4925int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4926 4927/* 4928** CAPI3REF: Automatically Load Statically Linked Extensions 4929** 4930** ^This interface causes the xEntryPoint() function to be invoked for 4931** each new [database connection] that is created. The idea here is that 4932** xEntryPoint() is the entry point for a statically linked SQLite extension 4933** that is to be automatically loaded into all new database connections. 4934** 4935** ^(Even though the function prototype shows that xEntryPoint() takes 4936** no arguments and returns void, SQLite invokes xEntryPoint() with three 4937** arguments and expects and integer result as if the signature of the 4938** entry point where as follows: 4939** 4940** <blockquote><pre> 4941** int xEntryPoint( 4942** sqlite3 *db, 4943** const char **pzErrMsg, 4944** const struct sqlite3_api_routines *pThunk 4945** ); 4946** </pre></blockquote>)^ 4947** 4948** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 4949** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 4950** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 4951** is NULL before calling the xEntryPoint(). ^SQLite will invoke 4952** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 4953** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 4954** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 4955** 4956** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 4957** on the list of automatic extensions is a harmless no-op. ^No entry point 4958** will be called more than once for each database connection that is opened. 4959** 4960** See also: [sqlite3_reset_auto_extension()]. 4961*/ 4962int sqlite3_auto_extension(void (*xEntryPoint)(void)); 4963 4964/* 4965** CAPI3REF: Reset Automatic Extension Loading 4966** 4967** ^This interface disables all automatic extensions previously 4968** registered using [sqlite3_auto_extension()]. 4969*/ 4970void sqlite3_reset_auto_extension(void); 4971 4972/* 4973** The interface to the virtual-table mechanism is currently considered 4974** to be experimental. The interface might change in incompatible ways. 4975** If this is a problem for you, do not use the interface at this time. 4976** 4977** When the virtual-table mechanism stabilizes, we will declare the 4978** interface fixed, support it indefinitely, and remove this comment. 4979*/ 4980 4981/* 4982** Structures used by the virtual table interface 4983*/ 4984typedef struct sqlite3_vtab sqlite3_vtab; 4985typedef struct sqlite3_index_info sqlite3_index_info; 4986typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4987typedef struct sqlite3_module sqlite3_module; 4988 4989/* 4990** CAPI3REF: Virtual Table Object 4991** KEYWORDS: sqlite3_module {virtual table module} 4992** 4993** This structure, sometimes called a "virtual table module", 4994** defines the implementation of a [virtual tables]. 4995** This structure consists mostly of methods for the module. 4996** 4997** ^A virtual table module is created by filling in a persistent 4998** instance of this structure and passing a pointer to that instance 4999** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5000** ^The registration remains valid until it is replaced by a different 5001** module or until the [database connection] closes. The content 5002** of this structure must not change while it is registered with 5003** any database connection. 5004*/ 5005struct sqlite3_module { 5006 int iVersion; 5007 int (*xCreate)(sqlite3*, void *pAux, 5008 int argc, const char *const*argv, 5009 sqlite3_vtab **ppVTab, char**); 5010 int (*xConnect)(sqlite3*, void *pAux, 5011 int argc, const char *const*argv, 5012 sqlite3_vtab **ppVTab, char**); 5013 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5014 int (*xDisconnect)(sqlite3_vtab *pVTab); 5015 int (*xDestroy)(sqlite3_vtab *pVTab); 5016 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5017 int (*xClose)(sqlite3_vtab_cursor*); 5018 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5019 int argc, sqlite3_value **argv); 5020 int (*xNext)(sqlite3_vtab_cursor*); 5021 int (*xEof)(sqlite3_vtab_cursor*); 5022 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5023 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5024 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5025 int (*xBegin)(sqlite3_vtab *pVTab); 5026 int (*xSync)(sqlite3_vtab *pVTab); 5027 int (*xCommit)(sqlite3_vtab *pVTab); 5028 int (*xRollback)(sqlite3_vtab *pVTab); 5029 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5030 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5031 void **ppArg); 5032 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5033 /* The methods above are in version 1 of the sqlite_module object. Those 5034 ** below are for version 2 and greater. */ 5035 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5036 int (*xRelease)(sqlite3_vtab *pVTab, int); 5037 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5038}; 5039 5040/* 5041** CAPI3REF: Virtual Table Indexing Information 5042** KEYWORDS: sqlite3_index_info 5043** 5044** The sqlite3_index_info structure and its substructures is used as part 5045** of the [virtual table] interface to 5046** pass information into and receive the reply from the [xBestIndex] 5047** method of a [virtual table module]. The fields under **Inputs** are the 5048** inputs to xBestIndex and are read-only. xBestIndex inserts its 5049** results into the **Outputs** fields. 5050** 5051** ^(The aConstraint[] array records WHERE clause constraints of the form: 5052** 5053** <blockquote>column OP expr</blockquote> 5054** 5055** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5056** stored in aConstraint[].op using one of the 5057** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5058** ^(The index of the column is stored in 5059** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5060** expr on the right-hand side can be evaluated (and thus the constraint 5061** is usable) and false if it cannot.)^ 5062** 5063** ^The optimizer automatically inverts terms of the form "expr OP column" 5064** and makes other simplifications to the WHERE clause in an attempt to 5065** get as many WHERE clause terms into the form shown above as possible. 5066** ^The aConstraint[] array only reports WHERE clause terms that are 5067** relevant to the particular virtual table being queried. 5068** 5069** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5070** ^Each term of aOrderBy records a column of the ORDER BY clause. 5071** 5072** The [xBestIndex] method must fill aConstraintUsage[] with information 5073** about what parameters to pass to xFilter. ^If argvIndex>0 then 5074** the right-hand side of the corresponding aConstraint[] is evaluated 5075** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5076** is true, then the constraint is assumed to be fully handled by the 5077** virtual table and is not checked again by SQLite.)^ 5078** 5079** ^The idxNum and idxPtr values are recorded and passed into the 5080** [xFilter] method. 5081** ^[sqlite3_free()] is used to free idxPtr if and only if 5082** needToFreeIdxPtr is true. 5083** 5084** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5085** the correct order to satisfy the ORDER BY clause so that no separate 5086** sorting step is required. 5087** 5088** ^The estimatedCost value is an estimate of the cost of doing the 5089** particular lookup. A full scan of a table with N entries should have 5090** a cost of N. A binary search of a table of N entries should have a 5091** cost of approximately log(N). 5092*/ 5093struct sqlite3_index_info { 5094 /* Inputs */ 5095 int nConstraint; /* Number of entries in aConstraint */ 5096 struct sqlite3_index_constraint { 5097 int iColumn; /* Column on left-hand side of constraint */ 5098 unsigned char op; /* Constraint operator */ 5099 unsigned char usable; /* True if this constraint is usable */ 5100 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5101 } *aConstraint; /* Table of WHERE clause constraints */ 5102 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5103 struct sqlite3_index_orderby { 5104 int iColumn; /* Column number */ 5105 unsigned char desc; /* True for DESC. False for ASC. */ 5106 } *aOrderBy; /* The ORDER BY clause */ 5107 /* Outputs */ 5108 struct sqlite3_index_constraint_usage { 5109 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5110 unsigned char omit; /* Do not code a test for this constraint */ 5111 } *aConstraintUsage; 5112 int idxNum; /* Number used to identify the index */ 5113 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5114 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5115 int orderByConsumed; /* True if output is already ordered */ 5116 double estimatedCost; /* Estimated cost of using this index */ 5117}; 5118 5119/* 5120** CAPI3REF: Virtual Table Constraint Operator Codes 5121** 5122** These macros defined the allowed values for the 5123** [sqlite3_index_info].aConstraint[].op field. Each value represents 5124** an operator that is part of a constraint term in the wHERE clause of 5125** a query that uses a [virtual table]. 5126*/ 5127#define SQLITE_INDEX_CONSTRAINT_EQ 2 5128#define SQLITE_INDEX_CONSTRAINT_GT 4 5129#define SQLITE_INDEX_CONSTRAINT_LE 8 5130#define SQLITE_INDEX_CONSTRAINT_LT 16 5131#define SQLITE_INDEX_CONSTRAINT_GE 32 5132#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5133 5134/* 5135** CAPI3REF: Register A Virtual Table Implementation 5136** 5137** ^These routines are used to register a new [virtual table module] name. 5138** ^Module names must be registered before 5139** creating a new [virtual table] using the module and before using a 5140** preexisting [virtual table] for the module. 5141** 5142** ^The module name is registered on the [database connection] specified 5143** by the first parameter. ^The name of the module is given by the 5144** second parameter. ^The third parameter is a pointer to 5145** the implementation of the [virtual table module]. ^The fourth 5146** parameter is an arbitrary client data pointer that is passed through 5147** into the [xCreate] and [xConnect] methods of the virtual table module 5148** when a new virtual table is be being created or reinitialized. 5149** 5150** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5151** is a pointer to a destructor for the pClientData. ^SQLite will 5152** invoke the destructor function (if it is not NULL) when SQLite 5153** no longer needs the pClientData pointer. ^The destructor will also 5154** be invoked if the call to sqlite3_create_module_v2() fails. 5155** ^The sqlite3_create_module() 5156** interface is equivalent to sqlite3_create_module_v2() with a NULL 5157** destructor. 5158*/ 5159int sqlite3_create_module( 5160 sqlite3 *db, /* SQLite connection to register module with */ 5161 const char *zName, /* Name of the module */ 5162 const sqlite3_module *p, /* Methods for the module */ 5163 void *pClientData /* Client data for xCreate/xConnect */ 5164); 5165int sqlite3_create_module_v2( 5166 sqlite3 *db, /* SQLite connection to register module with */ 5167 const char *zName, /* Name of the module */ 5168 const sqlite3_module *p, /* Methods for the module */ 5169 void *pClientData, /* Client data for xCreate/xConnect */ 5170 void(*xDestroy)(void*) /* Module destructor function */ 5171); 5172 5173/* 5174** CAPI3REF: Virtual Table Instance Object 5175** KEYWORDS: sqlite3_vtab 5176** 5177** Every [virtual table module] implementation uses a subclass 5178** of this object to describe a particular instance 5179** of the [virtual table]. Each subclass will 5180** be tailored to the specific needs of the module implementation. 5181** The purpose of this superclass is to define certain fields that are 5182** common to all module implementations. 5183** 5184** ^Virtual tables methods can set an error message by assigning a 5185** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5186** take care that any prior string is freed by a call to [sqlite3_free()] 5187** prior to assigning a new string to zErrMsg. ^After the error message 5188** is delivered up to the client application, the string will be automatically 5189** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5190*/ 5191struct sqlite3_vtab { 5192 const sqlite3_module *pModule; /* The module for this virtual table */ 5193 int nRef; /* NO LONGER USED */ 5194 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5195 /* Virtual table implementations will typically add additional fields */ 5196}; 5197 5198/* 5199** CAPI3REF: Virtual Table Cursor Object 5200** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5201** 5202** Every [virtual table module] implementation uses a subclass of the 5203** following structure to describe cursors that point into the 5204** [virtual table] and are used 5205** to loop through the virtual table. Cursors are created using the 5206** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5207** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5208** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5209** of the module. Each module implementation will define 5210** the content of a cursor structure to suit its own needs. 5211** 5212** This superclass exists in order to define fields of the cursor that 5213** are common to all implementations. 5214*/ 5215struct sqlite3_vtab_cursor { 5216 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5217 /* Virtual table implementations will typically add additional fields */ 5218}; 5219 5220/* 5221** CAPI3REF: Declare The Schema Of A Virtual Table 5222** 5223** ^The [xCreate] and [xConnect] methods of a 5224** [virtual table module] call this interface 5225** to declare the format (the names and datatypes of the columns) of 5226** the virtual tables they implement. 5227*/ 5228int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5229 5230/* 5231** CAPI3REF: Overload A Function For A Virtual Table 5232** 5233** ^(Virtual tables can provide alternative implementations of functions 5234** using the [xFindFunction] method of the [virtual table module]. 5235** But global versions of those functions 5236** must exist in order to be overloaded.)^ 5237** 5238** ^(This API makes sure a global version of a function with a particular 5239** name and number of parameters exists. If no such function exists 5240** before this API is called, a new function is created.)^ ^The implementation 5241** of the new function always causes an exception to be thrown. So 5242** the new function is not good for anything by itself. Its only 5243** purpose is to be a placeholder function that can be overloaded 5244** by a [virtual table]. 5245*/ 5246int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5247 5248/* 5249** The interface to the virtual-table mechanism defined above (back up 5250** to a comment remarkably similar to this one) is currently considered 5251** to be experimental. The interface might change in incompatible ways. 5252** If this is a problem for you, do not use the interface at this time. 5253** 5254** When the virtual-table mechanism stabilizes, we will declare the 5255** interface fixed, support it indefinitely, and remove this comment. 5256*/ 5257 5258/* 5259** CAPI3REF: A Handle To An Open BLOB 5260** KEYWORDS: {BLOB handle} {BLOB handles} 5261** 5262** An instance of this object represents an open BLOB on which 5263** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5264** ^Objects of this type are created by [sqlite3_blob_open()] 5265** and destroyed by [sqlite3_blob_close()]. 5266** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5267** can be used to read or write small subsections of the BLOB. 5268** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5269*/ 5270typedef struct sqlite3_blob sqlite3_blob; 5271 5272/* 5273** CAPI3REF: Open A BLOB For Incremental I/O 5274** 5275** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5276** in row iRow, column zColumn, table zTable in database zDb; 5277** in other words, the same BLOB that would be selected by: 5278** 5279** <pre> 5280** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5281** </pre>)^ 5282** 5283** ^If the flags parameter is non-zero, then the BLOB is opened for read 5284** and write access. ^If it is zero, the BLOB is opened for read access. 5285** ^It is not possible to open a column that is part of an index or primary 5286** key for writing. ^If [foreign key constraints] are enabled, it is 5287** not possible to open a column that is part of a [child key] for writing. 5288** 5289** ^Note that the database name is not the filename that contains 5290** the database but rather the symbolic name of the database that 5291** appears after the AS keyword when the database is connected using [ATTACH]. 5292** ^For the main database file, the database name is "main". 5293** ^For TEMP tables, the database name is "temp". 5294** 5295** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5296** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5297** to be a null pointer.)^ 5298** ^This function sets the [database connection] error code and message 5299** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5300** functions. ^Note that the *ppBlob variable is always initialized in a 5301** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5302** regardless of the success or failure of this routine. 5303** 5304** ^(If the row that a BLOB handle points to is modified by an 5305** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5306** then the BLOB handle is marked as "expired". 5307** This is true if any column of the row is changed, even a column 5308** other than the one the BLOB handle is open on.)^ 5309** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5310** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5311** ^(Changes written into a BLOB prior to the BLOB expiring are not 5312** rolled back by the expiration of the BLOB. Such changes will eventually 5313** commit if the transaction continues to completion.)^ 5314** 5315** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5316** the opened blob. ^The size of a blob may not be changed by this 5317** interface. Use the [UPDATE] SQL command to change the size of a 5318** blob. 5319** 5320** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5321** and the built-in [zeroblob] SQL function can be used, if desired, 5322** to create an empty, zero-filled blob in which to read or write using 5323** this interface. 5324** 5325** To avoid a resource leak, every open [BLOB handle] should eventually 5326** be released by a call to [sqlite3_blob_close()]. 5327*/ 5328int sqlite3_blob_open( 5329 sqlite3*, 5330 const char *zDb, 5331 const char *zTable, 5332 const char *zColumn, 5333 sqlite3_int64 iRow, 5334 int flags, 5335 sqlite3_blob **ppBlob 5336); 5337 5338/* 5339** CAPI3REF: Move a BLOB Handle to a New Row 5340** 5341** ^This function is used to move an existing blob handle so that it points 5342** to a different row of the same database table. ^The new row is identified 5343** by the rowid value passed as the second argument. Only the row can be 5344** changed. ^The database, table and column on which the blob handle is open 5345** remain the same. Moving an existing blob handle to a new row can be 5346** faster than closing the existing handle and opening a new one. 5347** 5348** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5349** it must exist and there must be either a blob or text value stored in 5350** the nominated column.)^ ^If the new row is not present in the table, or if 5351** it does not contain a blob or text value, or if another error occurs, an 5352** SQLite error code is returned and the blob handle is considered aborted. 5353** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5354** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5355** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5356** always returns zero. 5357** 5358** ^This function sets the database handle error code and message. 5359*/ 5360SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5361 5362/* 5363** CAPI3REF: Close A BLOB Handle 5364** 5365** ^Closes an open [BLOB handle]. 5366** 5367** ^Closing a BLOB shall cause the current transaction to commit 5368** if there are no other BLOBs, no pending prepared statements, and the 5369** database connection is in [autocommit mode]. 5370** ^If any writes were made to the BLOB, they might be held in cache 5371** until the close operation if they will fit. 5372** 5373** ^(Closing the BLOB often forces the changes 5374** out to disk and so if any I/O errors occur, they will likely occur 5375** at the time when the BLOB is closed. Any errors that occur during 5376** closing are reported as a non-zero return value.)^ 5377** 5378** ^(The BLOB is closed unconditionally. Even if this routine returns 5379** an error code, the BLOB is still closed.)^ 5380** 5381** ^Calling this routine with a null pointer (such as would be returned 5382** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5383*/ 5384int sqlite3_blob_close(sqlite3_blob *); 5385 5386/* 5387** CAPI3REF: Return The Size Of An Open BLOB 5388** 5389** ^Returns the size in bytes of the BLOB accessible via the 5390** successfully opened [BLOB handle] in its only argument. ^The 5391** incremental blob I/O routines can only read or overwriting existing 5392** blob content; they cannot change the size of a blob. 5393** 5394** This routine only works on a [BLOB handle] which has been created 5395** by a prior successful call to [sqlite3_blob_open()] and which has not 5396** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5397** to this routine results in undefined and probably undesirable behavior. 5398*/ 5399int sqlite3_blob_bytes(sqlite3_blob *); 5400 5401/* 5402** CAPI3REF: Read Data From A BLOB Incrementally 5403** 5404** ^(This function is used to read data from an open [BLOB handle] into a 5405** caller-supplied buffer. N bytes of data are copied into buffer Z 5406** from the open BLOB, starting at offset iOffset.)^ 5407** 5408** ^If offset iOffset is less than N bytes from the end of the BLOB, 5409** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5410** less than zero, [SQLITE_ERROR] is returned and no data is read. 5411** ^The size of the blob (and hence the maximum value of N+iOffset) 5412** can be determined using the [sqlite3_blob_bytes()] interface. 5413** 5414** ^An attempt to read from an expired [BLOB handle] fails with an 5415** error code of [SQLITE_ABORT]. 5416** 5417** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5418** Otherwise, an [error code] or an [extended error code] is returned.)^ 5419** 5420** This routine only works on a [BLOB handle] which has been created 5421** by a prior successful call to [sqlite3_blob_open()] and which has not 5422** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5423** to this routine results in undefined and probably undesirable behavior. 5424** 5425** See also: [sqlite3_blob_write()]. 5426*/ 5427int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5428 5429/* 5430** CAPI3REF: Write Data Into A BLOB Incrementally 5431** 5432** ^This function is used to write data into an open [BLOB handle] from a 5433** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5434** into the open BLOB, starting at offset iOffset. 5435** 5436** ^If the [BLOB handle] passed as the first argument was not opened for 5437** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5438** this function returns [SQLITE_READONLY]. 5439** 5440** ^This function may only modify the contents of the BLOB; it is 5441** not possible to increase the size of a BLOB using this API. 5442** ^If offset iOffset is less than N bytes from the end of the BLOB, 5443** [SQLITE_ERROR] is returned and no data is written. ^If N is 5444** less than zero [SQLITE_ERROR] is returned and no data is written. 5445** The size of the BLOB (and hence the maximum value of N+iOffset) 5446** can be determined using the [sqlite3_blob_bytes()] interface. 5447** 5448** ^An attempt to write to an expired [BLOB handle] fails with an 5449** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5450** before the [BLOB handle] expired are not rolled back by the 5451** expiration of the handle, though of course those changes might 5452** have been overwritten by the statement that expired the BLOB handle 5453** or by other independent statements. 5454** 5455** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5456** Otherwise, an [error code] or an [extended error code] is returned.)^ 5457** 5458** This routine only works on a [BLOB handle] which has been created 5459** by a prior successful call to [sqlite3_blob_open()] and which has not 5460** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5461** to this routine results in undefined and probably undesirable behavior. 5462** 5463** See also: [sqlite3_blob_read()]. 5464*/ 5465int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5466 5467/* 5468** CAPI3REF: Virtual File System Objects 5469** 5470** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5471** that SQLite uses to interact 5472** with the underlying operating system. Most SQLite builds come with a 5473** single default VFS that is appropriate for the host computer. 5474** New VFSes can be registered and existing VFSes can be unregistered. 5475** The following interfaces are provided. 5476** 5477** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5478** ^Names are case sensitive. 5479** ^Names are zero-terminated UTF-8 strings. 5480** ^If there is no match, a NULL pointer is returned. 5481** ^If zVfsName is NULL then the default VFS is returned. 5482** 5483** ^New VFSes are registered with sqlite3_vfs_register(). 5484** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5485** ^The same VFS can be registered multiple times without injury. 5486** ^To make an existing VFS into the default VFS, register it again 5487** with the makeDflt flag set. If two different VFSes with the 5488** same name are registered, the behavior is undefined. If a 5489** VFS is registered with a name that is NULL or an empty string, 5490** then the behavior is undefined. 5491** 5492** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5493** ^(If the default VFS is unregistered, another VFS is chosen as 5494** the default. The choice for the new VFS is arbitrary.)^ 5495*/ 5496sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5497int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5498int sqlite3_vfs_unregister(sqlite3_vfs*); 5499 5500/* 5501** CAPI3REF: Mutexes 5502** 5503** The SQLite core uses these routines for thread 5504** synchronization. Though they are intended for internal 5505** use by SQLite, code that links against SQLite is 5506** permitted to use any of these routines. 5507** 5508** The SQLite source code contains multiple implementations 5509** of these mutex routines. An appropriate implementation 5510** is selected automatically at compile-time. ^(The following 5511** implementations are available in the SQLite core: 5512** 5513** <ul> 5514** <li> SQLITE_MUTEX_PTHREADS 5515** <li> SQLITE_MUTEX_W32 5516** <li> SQLITE_MUTEX_NOOP 5517** </ul>)^ 5518** 5519** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5520** that does no real locking and is appropriate for use in 5521** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and 5522** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5523** and Windows. 5524** 5525** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5526** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5527** implementation is included with the library. In this case the 5528** application must supply a custom mutex implementation using the 5529** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5530** before calling sqlite3_initialize() or any other public sqlite3_ 5531** function that calls sqlite3_initialize().)^ 5532** 5533** ^The sqlite3_mutex_alloc() routine allocates a new 5534** mutex and returns a pointer to it. ^If it returns NULL 5535** that means that a mutex could not be allocated. ^SQLite 5536** will unwind its stack and return an error. ^(The argument 5537** to sqlite3_mutex_alloc() is one of these integer constants: 5538** 5539** <ul> 5540** <li> SQLITE_MUTEX_FAST 5541** <li> SQLITE_MUTEX_RECURSIVE 5542** <li> SQLITE_MUTEX_STATIC_MASTER 5543** <li> SQLITE_MUTEX_STATIC_MEM 5544** <li> SQLITE_MUTEX_STATIC_MEM2 5545** <li> SQLITE_MUTEX_STATIC_PRNG 5546** <li> SQLITE_MUTEX_STATIC_LRU 5547** <li> SQLITE_MUTEX_STATIC_LRU2 5548** </ul>)^ 5549** 5550** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5551** cause sqlite3_mutex_alloc() to create 5552** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5553** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5554** The mutex implementation does not need to make a distinction 5555** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5556** not want to. ^SQLite will only request a recursive mutex in 5557** cases where it really needs one. ^If a faster non-recursive mutex 5558** implementation is available on the host platform, the mutex subsystem 5559** might return such a mutex in response to SQLITE_MUTEX_FAST. 5560** 5561** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5562** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5563** a pointer to a static preexisting mutex. ^Six static mutexes are 5564** used by the current version of SQLite. Future versions of SQLite 5565** may add additional static mutexes. Static mutexes are for internal 5566** use by SQLite only. Applications that use SQLite mutexes should 5567** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5568** SQLITE_MUTEX_RECURSIVE. 5569** 5570** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5571** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5572** returns a different mutex on every call. ^But for the static 5573** mutex types, the same mutex is returned on every call that has 5574** the same type number. 5575** 5576** ^The sqlite3_mutex_free() routine deallocates a previously 5577** allocated dynamic mutex. ^SQLite is careful to deallocate every 5578** dynamic mutex that it allocates. The dynamic mutexes must not be in 5579** use when they are deallocated. Attempting to deallocate a static 5580** mutex results in undefined behavior. ^SQLite never deallocates 5581** a static mutex. 5582** 5583** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5584** to enter a mutex. ^If another thread is already within the mutex, 5585** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5586** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5587** upon successful entry. ^(Mutexes created using 5588** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5589** In such cases the, 5590** mutex must be exited an equal number of times before another thread 5591** can enter.)^ ^(If the same thread tries to enter any other 5592** kind of mutex more than once, the behavior is undefined. 5593** SQLite will never exhibit 5594** such behavior in its own use of mutexes.)^ 5595** 5596** ^(Some systems (for example, Windows 95) do not support the operation 5597** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5598** will always return SQLITE_BUSY. The SQLite core only ever uses 5599** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5600** 5601** ^The sqlite3_mutex_leave() routine exits a mutex that was 5602** previously entered by the same thread. ^(The behavior 5603** is undefined if the mutex is not currently entered by the 5604** calling thread or is not currently allocated. SQLite will 5605** never do either.)^ 5606** 5607** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5608** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5609** behave as no-ops. 5610** 5611** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5612*/ 5613sqlite3_mutex *sqlite3_mutex_alloc(int); 5614void sqlite3_mutex_free(sqlite3_mutex*); 5615void sqlite3_mutex_enter(sqlite3_mutex*); 5616int sqlite3_mutex_try(sqlite3_mutex*); 5617void sqlite3_mutex_leave(sqlite3_mutex*); 5618 5619/* 5620** CAPI3REF: Mutex Methods Object 5621** 5622** An instance of this structure defines the low-level routines 5623** used to allocate and use mutexes. 5624** 5625** Usually, the default mutex implementations provided by SQLite are 5626** sufficient, however the user has the option of substituting a custom 5627** implementation for specialized deployments or systems for which SQLite 5628** does not provide a suitable implementation. In this case, the user 5629** creates and populates an instance of this structure to pass 5630** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5631** Additionally, an instance of this structure can be used as an 5632** output variable when querying the system for the current mutex 5633** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5634** 5635** ^The xMutexInit method defined by this structure is invoked as 5636** part of system initialization by the sqlite3_initialize() function. 5637** ^The xMutexInit routine is called by SQLite exactly once for each 5638** effective call to [sqlite3_initialize()]. 5639** 5640** ^The xMutexEnd method defined by this structure is invoked as 5641** part of system shutdown by the sqlite3_shutdown() function. The 5642** implementation of this method is expected to release all outstanding 5643** resources obtained by the mutex methods implementation, especially 5644** those obtained by the xMutexInit method. ^The xMutexEnd() 5645** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5646** 5647** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5648** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5649** xMutexNotheld) implement the following interfaces (respectively): 5650** 5651** <ul> 5652** <li> [sqlite3_mutex_alloc()] </li> 5653** <li> [sqlite3_mutex_free()] </li> 5654** <li> [sqlite3_mutex_enter()] </li> 5655** <li> [sqlite3_mutex_try()] </li> 5656** <li> [sqlite3_mutex_leave()] </li> 5657** <li> [sqlite3_mutex_held()] </li> 5658** <li> [sqlite3_mutex_notheld()] </li> 5659** </ul>)^ 5660** 5661** The only difference is that the public sqlite3_XXX functions enumerated 5662** above silently ignore any invocations that pass a NULL pointer instead 5663** of a valid mutex handle. The implementations of the methods defined 5664** by this structure are not required to handle this case, the results 5665** of passing a NULL pointer instead of a valid mutex handle are undefined 5666** (i.e. it is acceptable to provide an implementation that segfaults if 5667** it is passed a NULL pointer). 5668** 5669** The xMutexInit() method must be threadsafe. ^It must be harmless to 5670** invoke xMutexInit() multiple times within the same process and without 5671** intervening calls to xMutexEnd(). Second and subsequent calls to 5672** xMutexInit() must be no-ops. 5673** 5674** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5675** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5676** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5677** memory allocation for a fast or recursive mutex. 5678** 5679** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5680** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5681** If xMutexInit fails in any way, it is expected to clean up after itself 5682** prior to returning. 5683*/ 5684typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5685struct sqlite3_mutex_methods { 5686 int (*xMutexInit)(void); 5687 int (*xMutexEnd)(void); 5688 sqlite3_mutex *(*xMutexAlloc)(int); 5689 void (*xMutexFree)(sqlite3_mutex *); 5690 void (*xMutexEnter)(sqlite3_mutex *); 5691 int (*xMutexTry)(sqlite3_mutex *); 5692 void (*xMutexLeave)(sqlite3_mutex *); 5693 int (*xMutexHeld)(sqlite3_mutex *); 5694 int (*xMutexNotheld)(sqlite3_mutex *); 5695}; 5696 5697/* 5698** CAPI3REF: Mutex Verification Routines 5699** 5700** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5701** are intended for use inside assert() statements. ^The SQLite core 5702** never uses these routines except inside an assert() and applications 5703** are advised to follow the lead of the core. ^The SQLite core only 5704** provides implementations for these routines when it is compiled 5705** with the SQLITE_DEBUG flag. ^External mutex implementations 5706** are only required to provide these routines if SQLITE_DEBUG is 5707** defined and if NDEBUG is not defined. 5708** 5709** ^These routines should return true if the mutex in their argument 5710** is held or not held, respectively, by the calling thread. 5711** 5712** ^The implementation is not required to provide versions of these 5713** routines that actually work. If the implementation does not provide working 5714** versions of these routines, it should at least provide stubs that always 5715** return true so that one does not get spurious assertion failures. 5716** 5717** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5718** the routine should return 1. This seems counter-intuitive since 5719** clearly the mutex cannot be held if it does not exist. But 5720** the reason the mutex does not exist is because the build is not 5721** using mutexes. And we do not want the assert() containing the 5722** call to sqlite3_mutex_held() to fail, so a non-zero return is 5723** the appropriate thing to do. ^The sqlite3_mutex_notheld() 5724** interface should also return 1 when given a NULL pointer. 5725*/ 5726#ifndef NDEBUG 5727int sqlite3_mutex_held(sqlite3_mutex*); 5728int sqlite3_mutex_notheld(sqlite3_mutex*); 5729#endif 5730 5731/* 5732** CAPI3REF: Mutex Types 5733** 5734** The [sqlite3_mutex_alloc()] interface takes a single argument 5735** which is one of these integer constants. 5736** 5737** The set of static mutexes may change from one SQLite release to the 5738** next. Applications that override the built-in mutex logic must be 5739** prepared to accommodate additional static mutexes. 5740*/ 5741#define SQLITE_MUTEX_FAST 0 5742#define SQLITE_MUTEX_RECURSIVE 1 5743#define SQLITE_MUTEX_STATIC_MASTER 2 5744#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5745#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 5746#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 5747#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5748#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5749#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 5750#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 5751 5752/* 5753** CAPI3REF: Retrieve the mutex for a database connection 5754** 5755** ^This interface returns a pointer the [sqlite3_mutex] object that 5756** serializes access to the [database connection] given in the argument 5757** when the [threading mode] is Serialized. 5758** ^If the [threading mode] is Single-thread or Multi-thread then this 5759** routine returns a NULL pointer. 5760*/ 5761sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 5762 5763/* 5764** CAPI3REF: Low-Level Control Of Database Files 5765** 5766** ^The [sqlite3_file_control()] interface makes a direct call to the 5767** xFileControl method for the [sqlite3_io_methods] object associated 5768** with a particular database identified by the second argument. ^The 5769** name of the database is "main" for the main database or "temp" for the 5770** TEMP database, or the name that appears after the AS keyword for 5771** databases that are added using the [ATTACH] SQL command. 5772** ^A NULL pointer can be used in place of "main" to refer to the 5773** main database file. 5774** ^The third and fourth parameters to this routine 5775** are passed directly through to the second and third parameters of 5776** the xFileControl method. ^The return value of the xFileControl 5777** method becomes the return value of this routine. 5778** 5779** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 5780** a pointer to the underlying [sqlite3_file] object to be written into 5781** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 5782** case is a short-circuit path which does not actually invoke the 5783** underlying sqlite3_io_methods.xFileControl method. 5784** 5785** ^If the second parameter (zDbName) does not match the name of any 5786** open database file, then SQLITE_ERROR is returned. ^This error 5787** code is not remembered and will not be recalled by [sqlite3_errcode()] 5788** or [sqlite3_errmsg()]. The underlying xFileControl method might 5789** also return SQLITE_ERROR. There is no way to distinguish between 5790** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5791** xFileControl method. 5792** 5793** See also: [SQLITE_FCNTL_LOCKSTATE] 5794*/ 5795int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5796 5797/* 5798** CAPI3REF: Testing Interface 5799** 5800** ^The sqlite3_test_control() interface is used to read out internal 5801** state of SQLite and to inject faults into SQLite for testing 5802** purposes. ^The first parameter is an operation code that determines 5803** the number, meaning, and operation of all subsequent parameters. 5804** 5805** This interface is not for use by applications. It exists solely 5806** for verifying the correct operation of the SQLite library. Depending 5807** on how the SQLite library is compiled, this interface might not exist. 5808** 5809** The details of the operation codes, their meanings, the parameters 5810** they take, and what they do are all subject to change without notice. 5811** Unlike most of the SQLite API, this function is not guaranteed to 5812** operate consistently from one release to the next. 5813*/ 5814int sqlite3_test_control(int op, ...); 5815 5816/* 5817** CAPI3REF: Testing Interface Operation Codes 5818** 5819** These constants are the valid operation code parameters used 5820** as the first argument to [sqlite3_test_control()]. 5821** 5822** These parameters and their meanings are subject to change 5823** without notice. These values are for testing purposes only. 5824** Applications should not use any of these parameters or the 5825** [sqlite3_test_control()] interface. 5826*/ 5827#define SQLITE_TESTCTRL_FIRST 5 5828#define SQLITE_TESTCTRL_PRNG_SAVE 5 5829#define SQLITE_TESTCTRL_PRNG_RESTORE 6 5830#define SQLITE_TESTCTRL_PRNG_RESET 7 5831#define SQLITE_TESTCTRL_BITVEC_TEST 8 5832#define SQLITE_TESTCTRL_FAULT_INSTALL 9 5833#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 5834#define SQLITE_TESTCTRL_PENDING_BYTE 11 5835#define SQLITE_TESTCTRL_ASSERT 12 5836#define SQLITE_TESTCTRL_ALWAYS 13 5837#define SQLITE_TESTCTRL_RESERVE 14 5838#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 5839#define SQLITE_TESTCTRL_ISKEYWORD 16 5840#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 5841#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 5842#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 5843#define SQLITE_TESTCTRL_LAST 19 5844 5845/* 5846** CAPI3REF: SQLite Runtime Status 5847** 5848** ^This interface is used to retrieve runtime status information 5849** about the performance of SQLite, and optionally to reset various 5850** highwater marks. ^The first argument is an integer code for 5851** the specific parameter to measure. ^(Recognized integer codes 5852** are of the form [status parameters | SQLITE_STATUS_...].)^ 5853** ^The current value of the parameter is returned into *pCurrent. 5854** ^The highest recorded value is returned in *pHighwater. ^If the 5855** resetFlag is true, then the highest record value is reset after 5856** *pHighwater is written. ^(Some parameters do not record the highest 5857** value. For those parameters 5858** nothing is written into *pHighwater and the resetFlag is ignored.)^ 5859** ^(Other parameters record only the highwater mark and not the current 5860** value. For these latter parameters nothing is written into *pCurrent.)^ 5861** 5862** ^The sqlite3_status() routine returns SQLITE_OK on success and a 5863** non-zero [error code] on failure. 5864** 5865** This routine is threadsafe but is not atomic. This routine can be 5866** called while other threads are running the same or different SQLite 5867** interfaces. However the values returned in *pCurrent and 5868** *pHighwater reflect the status of SQLite at different points in time 5869** and it is possible that another thread might change the parameter 5870** in between the times when *pCurrent and *pHighwater are written. 5871** 5872** See also: [sqlite3_db_status()] 5873*/ 5874int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 5875 5876 5877/* 5878** CAPI3REF: Status Parameters 5879** KEYWORDS: {status parameters} 5880** 5881** These integer constants designate various run-time status parameters 5882** that can be returned by [sqlite3_status()]. 5883** 5884** <dl> 5885** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 5886** <dd>This parameter is the current amount of memory checked out 5887** using [sqlite3_malloc()], either directly or indirectly. The 5888** figure includes calls made to [sqlite3_malloc()] by the application 5889** and internal memory usage by the SQLite library. Scratch memory 5890** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 5891** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 5892** this parameter. The amount returned is the sum of the allocation 5893** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 5894** 5895** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 5896** <dd>This parameter records the largest memory allocation request 5897** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 5898** internal equivalents). Only the value returned in the 5899** *pHighwater parameter to [sqlite3_status()] is of interest. 5900** The value written into the *pCurrent parameter is undefined.</dd>)^ 5901** 5902** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 5903** <dd>This parameter records the number of separate memory allocations 5904** currently checked out.</dd>)^ 5905** 5906** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 5907** <dd>This parameter returns the number of pages used out of the 5908** [pagecache memory allocator] that was configured using 5909** [SQLITE_CONFIG_PAGECACHE]. The 5910** value returned is in pages, not in bytes.</dd>)^ 5911** 5912** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 5913** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 5914** <dd>This parameter returns the number of bytes of page cache 5915** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 5916** buffer and where forced to overflow to [sqlite3_malloc()]. The 5917** returned value includes allocations that overflowed because they 5918** where too large (they were larger than the "sz" parameter to 5919** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 5920** no space was left in the page cache.</dd>)^ 5921** 5922** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 5923** <dd>This parameter records the largest memory allocation request 5924** handed to [pagecache memory allocator]. Only the value returned in the 5925** *pHighwater parameter to [sqlite3_status()] is of interest. 5926** The value written into the *pCurrent parameter is undefined.</dd>)^ 5927** 5928** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 5929** <dd>This parameter returns the number of allocations used out of the 5930** [scratch memory allocator] configured using 5931** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 5932** in bytes. Since a single thread may only have one scratch allocation 5933** outstanding at time, this parameter also reports the number of threads 5934** using scratch memory at the same time.</dd>)^ 5935** 5936** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 5937** <dd>This parameter returns the number of bytes of scratch memory 5938** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 5939** buffer and where forced to overflow to [sqlite3_malloc()]. The values 5940** returned include overflows because the requested allocation was too 5941** larger (that is, because the requested allocation was larger than the 5942** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 5943** slots were available. 5944** </dd>)^ 5945** 5946** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 5947** <dd>This parameter records the largest memory allocation request 5948** handed to [scratch memory allocator]. Only the value returned in the 5949** *pHighwater parameter to [sqlite3_status()] is of interest. 5950** The value written into the *pCurrent parameter is undefined.</dd>)^ 5951** 5952** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 5953** <dd>This parameter records the deepest parser stack. It is only 5954** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 5955** </dl> 5956** 5957** New status parameters may be added from time to time. 5958*/ 5959#define SQLITE_STATUS_MEMORY_USED 0 5960#define SQLITE_STATUS_PAGECACHE_USED 1 5961#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 5962#define SQLITE_STATUS_SCRATCH_USED 3 5963#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 5964#define SQLITE_STATUS_MALLOC_SIZE 5 5965#define SQLITE_STATUS_PARSER_STACK 6 5966#define SQLITE_STATUS_PAGECACHE_SIZE 7 5967#define SQLITE_STATUS_SCRATCH_SIZE 8 5968#define SQLITE_STATUS_MALLOC_COUNT 9 5969 5970/* 5971** CAPI3REF: Database Connection Status 5972** 5973** ^This interface is used to retrieve runtime status information 5974** about a single [database connection]. ^The first argument is the 5975** database connection object to be interrogated. ^The second argument 5976** is an integer constant, taken from the set of 5977** [SQLITE_DBSTATUS options], that 5978** determines the parameter to interrogate. The set of 5979** [SQLITE_DBSTATUS options] is likely 5980** to grow in future releases of SQLite. 5981** 5982** ^The current value of the requested parameter is written into *pCur 5983** and the highest instantaneous value is written into *pHiwtr. ^If 5984** the resetFlg is true, then the highest instantaneous value is 5985** reset back down to the current value. 5986** 5987** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 5988** non-zero [error code] on failure. 5989** 5990** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 5991*/ 5992int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 5993 5994/* 5995** CAPI3REF: Status Parameters for database connections 5996** KEYWORDS: {SQLITE_DBSTATUS options} 5997** 5998** These constants are the available integer "verbs" that can be passed as 5999** the second argument to the [sqlite3_db_status()] interface. 6000** 6001** New verbs may be added in future releases of SQLite. Existing verbs 6002** might be discontinued. Applications should check the return code from 6003** [sqlite3_db_status()] to make sure that the call worked. 6004** The [sqlite3_db_status()] interface will return a non-zero error code 6005** if a discontinued or unsupported verb is invoked. 6006** 6007** <dl> 6008** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6009** <dd>This parameter returns the number of lookaside memory slots currently 6010** checked out.</dd>)^ 6011** 6012** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6013** <dd>This parameter returns the number malloc attempts that were 6014** satisfied using lookaside memory. Only the high-water value is meaningful; 6015** the current value is always zero.)^ 6016** 6017** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6018** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6019** <dd>This parameter returns the number malloc attempts that might have 6020** been satisfied using lookaside memory but failed due to the amount of 6021** memory requested being larger than the lookaside slot size. 6022** Only the high-water value is meaningful; 6023** the current value is always zero.)^ 6024** 6025** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6026** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6027** <dd>This parameter returns the number malloc attempts that might have 6028** been satisfied using lookaside memory but failed due to all lookaside 6029** memory already being in use. 6030** Only the high-water value is meaningful; 6031** the current value is always zero.)^ 6032** 6033** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6034** <dd>This parameter returns the approximate number of of bytes of heap 6035** memory used by all pager caches associated with the database connection.)^ 6036** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6037** 6038** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6039** <dd>This parameter returns the approximate number of of bytes of heap 6040** memory used to store the schema for all databases associated 6041** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6042** ^The full amount of memory used by the schemas is reported, even if the 6043** schema memory is shared with other database connections due to 6044** [shared cache mode] being enabled. 6045** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6046** 6047** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6048** <dd>This parameter returns the approximate number of of bytes of heap 6049** and lookaside memory used by all prepared statements associated with 6050** the database connection.)^ 6051** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6052** </dd> 6053** 6054** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6055** <dd>This parameter returns the number of pager cache hits that have 6056** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6057** is always 0. 6058** </dd> 6059** 6060** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6061** <dd>This parameter returns the number of pager cache misses that have 6062** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6063** is always 0. 6064** </dd> 6065** 6066** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6067** <dd>This parameter returns the number of dirty cache entries that have 6068** been written to disk. Specifically, the number of pages written to the 6069** wal file in wal mode databases, or the number of pages written to the 6070** database file in rollback mode databases. Any pages written as part of 6071** transaction rollback or database recovery operations are not included. 6072** If an IO or other error occurs while writing a page to disk, the effect 6073** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6074** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6075** </dd> 6076** </dl> 6077*/ 6078#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6079#define SQLITE_DBSTATUS_CACHE_USED 1 6080#define SQLITE_DBSTATUS_SCHEMA_USED 2 6081#define SQLITE_DBSTATUS_STMT_USED 3 6082#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6083#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6084#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6085#define SQLITE_DBSTATUS_CACHE_HIT 7 6086#define SQLITE_DBSTATUS_CACHE_MISS 8 6087#define SQLITE_DBSTATUS_CACHE_WRITE 9 6088#define SQLITE_DBSTATUS_MAX 9 /* Largest defined DBSTATUS */ 6089 6090 6091/* 6092** CAPI3REF: Prepared Statement Status 6093** 6094** ^(Each prepared statement maintains various 6095** [SQLITE_STMTSTATUS counters] that measure the number 6096** of times it has performed specific operations.)^ These counters can 6097** be used to monitor the performance characteristics of the prepared 6098** statements. For example, if the number of table steps greatly exceeds 6099** the number of table searches or result rows, that would tend to indicate 6100** that the prepared statement is using a full table scan rather than 6101** an index. 6102** 6103** ^(This interface is used to retrieve and reset counter values from 6104** a [prepared statement]. The first argument is the prepared statement 6105** object to be interrogated. The second argument 6106** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6107** to be interrogated.)^ 6108** ^The current value of the requested counter is returned. 6109** ^If the resetFlg is true, then the counter is reset to zero after this 6110** interface call returns. 6111** 6112** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6113*/ 6114int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6115 6116/* 6117** CAPI3REF: Status Parameters for prepared statements 6118** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6119** 6120** These preprocessor macros define integer codes that name counter 6121** values associated with the [sqlite3_stmt_status()] interface. 6122** The meanings of the various counters are as follows: 6123** 6124** <dl> 6125** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6126** <dd>^This is the number of times that SQLite has stepped forward in 6127** a table as part of a full table scan. Large numbers for this counter 6128** may indicate opportunities for performance improvement through 6129** careful use of indices.</dd> 6130** 6131** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6132** <dd>^This is the number of sort operations that have occurred. 6133** A non-zero value in this counter may indicate an opportunity to 6134** improvement performance through careful use of indices.</dd> 6135** 6136** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6137** <dd>^This is the number of rows inserted into transient indices that 6138** were created automatically in order to help joins run faster. 6139** A non-zero value in this counter may indicate an opportunity to 6140** improvement performance by adding permanent indices that do not 6141** need to be reinitialized each time the statement is run.</dd> 6142** </dl> 6143*/ 6144#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6145#define SQLITE_STMTSTATUS_SORT 2 6146#define SQLITE_STMTSTATUS_AUTOINDEX 3 6147 6148/* 6149** CAPI3REF: Custom Page Cache Object 6150** 6151** The sqlite3_pcache type is opaque. It is implemented by 6152** the pluggable module. The SQLite core has no knowledge of 6153** its size or internal structure and never deals with the 6154** sqlite3_pcache object except by holding and passing pointers 6155** to the object. 6156** 6157** See [sqlite3_pcache_methods2] for additional information. 6158*/ 6159typedef struct sqlite3_pcache sqlite3_pcache; 6160 6161/* 6162** CAPI3REF: Custom Page Cache Object 6163** 6164** The sqlite3_pcache_page object represents a single page in the 6165** page cache. The page cache will allocate instances of this 6166** object. Various methods of the page cache use pointers to instances 6167** of this object as parameters or as their return value. 6168** 6169** See [sqlite3_pcache_methods2] for additional information. 6170*/ 6171typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6172struct sqlite3_pcache_page { 6173 void *pBuf; /* The content of the page */ 6174 void *pExtra; /* Extra information associated with the page */ 6175}; 6176 6177/* 6178** CAPI3REF: Application Defined Page Cache. 6179** KEYWORDS: {page cache} 6180** 6181** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6182** register an alternative page cache implementation by passing in an 6183** instance of the sqlite3_pcache_methods2 structure.)^ 6184** In many applications, most of the heap memory allocated by 6185** SQLite is used for the page cache. 6186** By implementing a 6187** custom page cache using this API, an application can better control 6188** the amount of memory consumed by SQLite, the way in which 6189** that memory is allocated and released, and the policies used to 6190** determine exactly which parts of a database file are cached and for 6191** how long. 6192** 6193** The alternative page cache mechanism is an 6194** extreme measure that is only needed by the most demanding applications. 6195** The built-in page cache is recommended for most uses. 6196** 6197** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6198** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6199** the application may discard the parameter after the call to 6200** [sqlite3_config()] returns.)^ 6201** 6202** [[the xInit() page cache method]] 6203** ^(The xInit() method is called once for each effective 6204** call to [sqlite3_initialize()])^ 6205** (usually only once during the lifetime of the process). ^(The xInit() 6206** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6207** The intent of the xInit() method is to set up global data structures 6208** required by the custom page cache implementation. 6209** ^(If the xInit() method is NULL, then the 6210** built-in default page cache is used instead of the application defined 6211** page cache.)^ 6212** 6213** [[the xShutdown() page cache method]] 6214** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6215** It can be used to clean up 6216** any outstanding resources before process shutdown, if required. 6217** ^The xShutdown() method may be NULL. 6218** 6219** ^SQLite automatically serializes calls to the xInit method, 6220** so the xInit method need not be threadsafe. ^The 6221** xShutdown method is only called from [sqlite3_shutdown()] so it does 6222** not need to be threadsafe either. All other methods must be threadsafe 6223** in multithreaded applications. 6224** 6225** ^SQLite will never invoke xInit() more than once without an intervening 6226** call to xShutdown(). 6227** 6228** [[the xCreate() page cache methods]] 6229** ^SQLite invokes the xCreate() method to construct a new cache instance. 6230** SQLite will typically create one cache instance for each open database file, 6231** though this is not guaranteed. ^The 6232** first parameter, szPage, is the size in bytes of the pages that must 6233** be allocated by the cache. ^szPage will always a power of two. ^The 6234** second parameter szExtra is a number of bytes of extra storage 6235** associated with each page cache entry. ^The szExtra parameter will 6236** a number less than 250. SQLite will use the 6237** extra szExtra bytes on each page to store metadata about the underlying 6238** database page on disk. The value passed into szExtra depends 6239** on the SQLite version, the target platform, and how SQLite was compiled. 6240** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6241** created will be used to cache database pages of a file stored on disk, or 6242** false if it is used for an in-memory database. The cache implementation 6243** does not have to do anything special based with the value of bPurgeable; 6244** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6245** never invoke xUnpin() except to deliberately delete a page. 6246** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6247** false will always have the "discard" flag set to true. 6248** ^Hence, a cache created with bPurgeable false will 6249** never contain any unpinned pages. 6250** 6251** [[the xCachesize() page cache method]] 6252** ^(The xCachesize() method may be called at any time by SQLite to set the 6253** suggested maximum cache-size (number of pages stored by) the cache 6254** instance passed as the first argument. This is the value configured using 6255** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6256** parameter, the implementation is not required to do anything with this 6257** value; it is advisory only. 6258** 6259** [[the xPagecount() page cache methods]] 6260** The xPagecount() method must return the number of pages currently 6261** stored in the cache, both pinned and unpinned. 6262** 6263** [[the xFetch() page cache methods]] 6264** The xFetch() method locates a page in the cache and returns a pointer to 6265** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6266** The pBuf element of the returned sqlite3_pcache_page object will be a 6267** pointer to a buffer of szPage bytes used to store the content of a 6268** single database page. The pExtra element of sqlite3_pcache_page will be 6269** a pointer to the szExtra bytes of extra storage that SQLite has requested 6270** for each entry in the page cache. 6271** 6272** The page to be fetched is determined by the key. ^The minimum key value 6273** is 1. After it has been retrieved using xFetch, the page is considered 6274** to be "pinned". 6275** 6276** If the requested page is already in the page cache, then the page cache 6277** implementation must return a pointer to the page buffer with its content 6278** intact. If the requested page is not already in the cache, then the 6279** cache implementation should use the value of the createFlag 6280** parameter to help it determined what action to take: 6281** 6282** <table border=1 width=85% align=center> 6283** <tr><th> createFlag <th> Behaviour when page is not already in cache 6284** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6285** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6286** Otherwise return NULL. 6287** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6288** NULL if allocating a new page is effectively impossible. 6289** </table> 6290** 6291** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6292** will only use a createFlag of 2 after a prior call with a createFlag of 1 6293** failed.)^ In between the to xFetch() calls, SQLite may 6294** attempt to unpin one or more cache pages by spilling the content of 6295** pinned pages to disk and synching the operating system disk cache. 6296** 6297** [[the xUnpin() page cache method]] 6298** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6299** as its second argument. If the third parameter, discard, is non-zero, 6300** then the page must be evicted from the cache. 6301** ^If the discard parameter is 6302** zero, then the page may be discarded or retained at the discretion of 6303** page cache implementation. ^The page cache implementation 6304** may choose to evict unpinned pages at any time. 6305** 6306** The cache must not perform any reference counting. A single 6307** call to xUnpin() unpins the page regardless of the number of prior calls 6308** to xFetch(). 6309** 6310** [[the xRekey() page cache methods]] 6311** The xRekey() method is used to change the key value associated with the 6312** page passed as the second argument. If the cache 6313** previously contains an entry associated with newKey, it must be 6314** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6315** to be pinned. 6316** 6317** When SQLite calls the xTruncate() method, the cache must discard all 6318** existing cache entries with page numbers (keys) greater than or equal 6319** to the value of the iLimit parameter passed to xTruncate(). If any 6320** of these pages are pinned, they are implicitly unpinned, meaning that 6321** they can be safely discarded. 6322** 6323** [[the xDestroy() page cache method]] 6324** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6325** All resources associated with the specified cache should be freed. ^After 6326** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6327** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6328** functions. 6329** 6330** [[the xShrink() page cache method]] 6331** ^SQLite invokes the xShrink() method when it wants the page cache to 6332** free up as much of heap memory as possible. The page cache implementation 6333** is not obligated to free any memory, but well-behaved implementations should 6334** do their best. 6335*/ 6336typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6337struct sqlite3_pcache_methods2 { 6338 int iVersion; 6339 void *pArg; 6340 int (*xInit)(void*); 6341 void (*xShutdown)(void*); 6342 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6343 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6344 int (*xPagecount)(sqlite3_pcache*); 6345 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6346 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6347 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6348 unsigned oldKey, unsigned newKey); 6349 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6350 void (*xDestroy)(sqlite3_pcache*); 6351 void (*xShrink)(sqlite3_pcache*); 6352}; 6353 6354/* 6355** This is the obsolete pcache_methods object that has now been replaced 6356** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6357** retained in the header file for backwards compatibility only. 6358*/ 6359typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6360struct sqlite3_pcache_methods { 6361 void *pArg; 6362 int (*xInit)(void*); 6363 void (*xShutdown)(void*); 6364 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6365 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6366 int (*xPagecount)(sqlite3_pcache*); 6367 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6368 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6369 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6370 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6371 void (*xDestroy)(sqlite3_pcache*); 6372}; 6373 6374 6375/* 6376** CAPI3REF: Online Backup Object 6377** 6378** The sqlite3_backup object records state information about an ongoing 6379** online backup operation. ^The sqlite3_backup object is created by 6380** a call to [sqlite3_backup_init()] and is destroyed by a call to 6381** [sqlite3_backup_finish()]. 6382** 6383** See Also: [Using the SQLite Online Backup API] 6384*/ 6385typedef struct sqlite3_backup sqlite3_backup; 6386 6387/* 6388** CAPI3REF: Online Backup API. 6389** 6390** The backup API copies the content of one database into another. 6391** It is useful either for creating backups of databases or 6392** for copying in-memory databases to or from persistent files. 6393** 6394** See Also: [Using the SQLite Online Backup API] 6395** 6396** ^SQLite holds a write transaction open on the destination database file 6397** for the duration of the backup operation. 6398** ^The source database is read-locked only while it is being read; 6399** it is not locked continuously for the entire backup operation. 6400** ^Thus, the backup may be performed on a live source database without 6401** preventing other database connections from 6402** reading or writing to the source database while the backup is underway. 6403** 6404** ^(To perform a backup operation: 6405** <ol> 6406** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6407** backup, 6408** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6409** the data between the two databases, and finally 6410** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6411** associated with the backup operation. 6412** </ol>)^ 6413** There should be exactly one call to sqlite3_backup_finish() for each 6414** successful call to sqlite3_backup_init(). 6415** 6416** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6417** 6418** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6419** [database connection] associated with the destination database 6420** and the database name, respectively. 6421** ^The database name is "main" for the main database, "temp" for the 6422** temporary database, or the name specified after the AS keyword in 6423** an [ATTACH] statement for an attached database. 6424** ^The S and M arguments passed to 6425** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6426** and database name of the source database, respectively. 6427** ^The source and destination [database connections] (parameters S and D) 6428** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6429** an error. 6430** 6431** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6432** returned and an error code and error message are stored in the 6433** destination [database connection] D. 6434** ^The error code and message for the failed call to sqlite3_backup_init() 6435** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6436** [sqlite3_errmsg16()] functions. 6437** ^A successful call to sqlite3_backup_init() returns a pointer to an 6438** [sqlite3_backup] object. 6439** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6440** sqlite3_backup_finish() functions to perform the specified backup 6441** operation. 6442** 6443** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6444** 6445** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6446** the source and destination databases specified by [sqlite3_backup] object B. 6447** ^If N is negative, all remaining source pages are copied. 6448** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6449** are still more pages to be copied, then the function returns [SQLITE_OK]. 6450** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6451** from source to destination, then it returns [SQLITE_DONE]. 6452** ^If an error occurs while running sqlite3_backup_step(B,N), 6453** then an [error code] is returned. ^As well as [SQLITE_OK] and 6454** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6455** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6456** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6457** 6458** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6459** <ol> 6460** <li> the destination database was opened read-only, or 6461** <li> the destination database is using write-ahead-log journaling 6462** and the destination and source page sizes differ, or 6463** <li> the destination database is an in-memory database and the 6464** destination and source page sizes differ. 6465** </ol>)^ 6466** 6467** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6468** the [sqlite3_busy_handler | busy-handler function] 6469** is invoked (if one is specified). ^If the 6470** busy-handler returns non-zero before the lock is available, then 6471** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6472** sqlite3_backup_step() can be retried later. ^If the source 6473** [database connection] 6474** is being used to write to the source database when sqlite3_backup_step() 6475** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6476** case the call to sqlite3_backup_step() can be retried later on. ^(If 6477** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6478** [SQLITE_READONLY] is returned, then 6479** there is no point in retrying the call to sqlite3_backup_step(). These 6480** errors are considered fatal.)^ The application must accept 6481** that the backup operation has failed and pass the backup operation handle 6482** to the sqlite3_backup_finish() to release associated resources. 6483** 6484** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6485** on the destination file. ^The exclusive lock is not released until either 6486** sqlite3_backup_finish() is called or the backup operation is complete 6487** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6488** sqlite3_backup_step() obtains a [shared lock] on the source database that 6489** lasts for the duration of the sqlite3_backup_step() call. 6490** ^Because the source database is not locked between calls to 6491** sqlite3_backup_step(), the source database may be modified mid-way 6492** through the backup process. ^If the source database is modified by an 6493** external process or via a database connection other than the one being 6494** used by the backup operation, then the backup will be automatically 6495** restarted by the next call to sqlite3_backup_step(). ^If the source 6496** database is modified by the using the same database connection as is used 6497** by the backup operation, then the backup database is automatically 6498** updated at the same time. 6499** 6500** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6501** 6502** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6503** application wishes to abandon the backup operation, the application 6504** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6505** ^The sqlite3_backup_finish() interfaces releases all 6506** resources associated with the [sqlite3_backup] object. 6507** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6508** active write-transaction on the destination database is rolled back. 6509** The [sqlite3_backup] object is invalid 6510** and may not be used following a call to sqlite3_backup_finish(). 6511** 6512** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6513** sqlite3_backup_step() errors occurred, regardless or whether or not 6514** sqlite3_backup_step() completed. 6515** ^If an out-of-memory condition or IO error occurred during any prior 6516** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6517** sqlite3_backup_finish() returns the corresponding [error code]. 6518** 6519** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6520** is not a permanent error and does not affect the return value of 6521** sqlite3_backup_finish(). 6522** 6523** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6524** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6525** 6526** ^Each call to sqlite3_backup_step() sets two values inside 6527** the [sqlite3_backup] object: the number of pages still to be backed 6528** up and the total number of pages in the source database file. 6529** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6530** retrieve these two values, respectively. 6531** 6532** ^The values returned by these functions are only updated by 6533** sqlite3_backup_step(). ^If the source database is modified during a backup 6534** operation, then the values are not updated to account for any extra 6535** pages that need to be updated or the size of the source database file 6536** changing. 6537** 6538** <b>Concurrent Usage of Database Handles</b> 6539** 6540** ^The source [database connection] may be used by the application for other 6541** purposes while a backup operation is underway or being initialized. 6542** ^If SQLite is compiled and configured to support threadsafe database 6543** connections, then the source database connection may be used concurrently 6544** from within other threads. 6545** 6546** However, the application must guarantee that the destination 6547** [database connection] is not passed to any other API (by any thread) after 6548** sqlite3_backup_init() is called and before the corresponding call to 6549** sqlite3_backup_finish(). SQLite does not currently check to see 6550** if the application incorrectly accesses the destination [database connection] 6551** and so no error code is reported, but the operations may malfunction 6552** nevertheless. Use of the destination database connection while a 6553** backup is in progress might also also cause a mutex deadlock. 6554** 6555** If running in [shared cache mode], the application must 6556** guarantee that the shared cache used by the destination database 6557** is not accessed while the backup is running. In practice this means 6558** that the application must guarantee that the disk file being 6559** backed up to is not accessed by any connection within the process, 6560** not just the specific connection that was passed to sqlite3_backup_init(). 6561** 6562** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6563** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6564** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6565** APIs are not strictly speaking threadsafe. If they are invoked at the 6566** same time as another thread is invoking sqlite3_backup_step() it is 6567** possible that they return invalid values. 6568*/ 6569sqlite3_backup *sqlite3_backup_init( 6570 sqlite3 *pDest, /* Destination database handle */ 6571 const char *zDestName, /* Destination database name */ 6572 sqlite3 *pSource, /* Source database handle */ 6573 const char *zSourceName /* Source database name */ 6574); 6575int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6576int sqlite3_backup_finish(sqlite3_backup *p); 6577int sqlite3_backup_remaining(sqlite3_backup *p); 6578int sqlite3_backup_pagecount(sqlite3_backup *p); 6579 6580/* 6581** CAPI3REF: Unlock Notification 6582** 6583** ^When running in shared-cache mode, a database operation may fail with 6584** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6585** individual tables within the shared-cache cannot be obtained. See 6586** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6587** ^This API may be used to register a callback that SQLite will invoke 6588** when the connection currently holding the required lock relinquishes it. 6589** ^This API is only available if the library was compiled with the 6590** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6591** 6592** See Also: [Using the SQLite Unlock Notification Feature]. 6593** 6594** ^Shared-cache locks are released when a database connection concludes 6595** its current transaction, either by committing it or rolling it back. 6596** 6597** ^When a connection (known as the blocked connection) fails to obtain a 6598** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6599** identity of the database connection (the blocking connection) that 6600** has locked the required resource is stored internally. ^After an 6601** application receives an SQLITE_LOCKED error, it may call the 6602** sqlite3_unlock_notify() method with the blocked connection handle as 6603** the first argument to register for a callback that will be invoked 6604** when the blocking connections current transaction is concluded. ^The 6605** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6606** call that concludes the blocking connections transaction. 6607** 6608** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6609** there is a chance that the blocking connection will have already 6610** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6611** If this happens, then the specified callback is invoked immediately, 6612** from within the call to sqlite3_unlock_notify().)^ 6613** 6614** ^If the blocked connection is attempting to obtain a write-lock on a 6615** shared-cache table, and more than one other connection currently holds 6616** a read-lock on the same table, then SQLite arbitrarily selects one of 6617** the other connections to use as the blocking connection. 6618** 6619** ^(There may be at most one unlock-notify callback registered by a 6620** blocked connection. If sqlite3_unlock_notify() is called when the 6621** blocked connection already has a registered unlock-notify callback, 6622** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6623** called with a NULL pointer as its second argument, then any existing 6624** unlock-notify callback is canceled. ^The blocked connections 6625** unlock-notify callback may also be canceled by closing the blocked 6626** connection using [sqlite3_close()]. 6627** 6628** The unlock-notify callback is not reentrant. If an application invokes 6629** any sqlite3_xxx API functions from within an unlock-notify callback, a 6630** crash or deadlock may be the result. 6631** 6632** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6633** returns SQLITE_OK. 6634** 6635** <b>Callback Invocation Details</b> 6636** 6637** When an unlock-notify callback is registered, the application provides a 6638** single void* pointer that is passed to the callback when it is invoked. 6639** However, the signature of the callback function allows SQLite to pass 6640** it an array of void* context pointers. The first argument passed to 6641** an unlock-notify callback is a pointer to an array of void* pointers, 6642** and the second is the number of entries in the array. 6643** 6644** When a blocking connections transaction is concluded, there may be 6645** more than one blocked connection that has registered for an unlock-notify 6646** callback. ^If two or more such blocked connections have specified the 6647** same callback function, then instead of invoking the callback function 6648** multiple times, it is invoked once with the set of void* context pointers 6649** specified by the blocked connections bundled together into an array. 6650** This gives the application an opportunity to prioritize any actions 6651** related to the set of unblocked database connections. 6652** 6653** <b>Deadlock Detection</b> 6654** 6655** Assuming that after registering for an unlock-notify callback a 6656** database waits for the callback to be issued before taking any further 6657** action (a reasonable assumption), then using this API may cause the 6658** application to deadlock. For example, if connection X is waiting for 6659** connection Y's transaction to be concluded, and similarly connection 6660** Y is waiting on connection X's transaction, then neither connection 6661** will proceed and the system may remain deadlocked indefinitely. 6662** 6663** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6664** detection. ^If a given call to sqlite3_unlock_notify() would put the 6665** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6666** unlock-notify callback is registered. The system is said to be in 6667** a deadlocked state if connection A has registered for an unlock-notify 6668** callback on the conclusion of connection B's transaction, and connection 6669** B has itself registered for an unlock-notify callback when connection 6670** A's transaction is concluded. ^Indirect deadlock is also detected, so 6671** the system is also considered to be deadlocked if connection B has 6672** registered for an unlock-notify callback on the conclusion of connection 6673** C's transaction, where connection C is waiting on connection A. ^Any 6674** number of levels of indirection are allowed. 6675** 6676** <b>The "DROP TABLE" Exception</b> 6677** 6678** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6679** always appropriate to call sqlite3_unlock_notify(). There is however, 6680** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6681** SQLite checks if there are any currently executing SELECT statements 6682** that belong to the same connection. If there are, SQLITE_LOCKED is 6683** returned. In this case there is no "blocking connection", so invoking 6684** sqlite3_unlock_notify() results in the unlock-notify callback being 6685** invoked immediately. If the application then re-attempts the "DROP TABLE" 6686** or "DROP INDEX" query, an infinite loop might be the result. 6687** 6688** One way around this problem is to check the extended error code returned 6689** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6690** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6691** the special "DROP TABLE/INDEX" case, the extended error code is just 6692** SQLITE_LOCKED.)^ 6693*/ 6694int sqlite3_unlock_notify( 6695 sqlite3 *pBlocked, /* Waiting connection */ 6696 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6697 void *pNotifyArg /* Argument to pass to xNotify */ 6698); 6699 6700 6701/* 6702** CAPI3REF: String Comparison 6703** 6704** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 6705** and extensions to compare the contents of two buffers containing UTF-8 6706** strings in a case-independent fashion, using the same definition of "case 6707** independence" that SQLite uses internally when comparing identifiers. 6708*/ 6709int sqlite3_stricmp(const char *, const char *); 6710int sqlite3_strnicmp(const char *, const char *, int); 6711 6712/* 6713** CAPI3REF: Error Logging Interface 6714** 6715** ^The [sqlite3_log()] interface writes a message into the error log 6716** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 6717** ^If logging is enabled, the zFormat string and subsequent arguments are 6718** used with [sqlite3_snprintf()] to generate the final output string. 6719** 6720** The sqlite3_log() interface is intended for use by extensions such as 6721** virtual tables, collating functions, and SQL functions. While there is 6722** nothing to prevent an application from calling sqlite3_log(), doing so 6723** is considered bad form. 6724** 6725** The zFormat string must not be NULL. 6726** 6727** To avoid deadlocks and other threading problems, the sqlite3_log() routine 6728** will not use dynamically allocated memory. The log message is stored in 6729** a fixed-length buffer on the stack. If the log message is longer than 6730** a few hundred characters, it will be truncated to the length of the 6731** buffer. 6732*/ 6733void sqlite3_log(int iErrCode, const char *zFormat, ...); 6734 6735/* 6736** CAPI3REF: Write-Ahead Log Commit Hook 6737** 6738** ^The [sqlite3_wal_hook()] function is used to register a callback that 6739** will be invoked each time a database connection commits data to a 6740** [write-ahead log] (i.e. whenever a transaction is committed in 6741** [journal_mode | journal_mode=WAL mode]). 6742** 6743** ^The callback is invoked by SQLite after the commit has taken place and 6744** the associated write-lock on the database released, so the implementation 6745** may read, write or [checkpoint] the database as required. 6746** 6747** ^The first parameter passed to the callback function when it is invoked 6748** is a copy of the third parameter passed to sqlite3_wal_hook() when 6749** registering the callback. ^The second is a copy of the database handle. 6750** ^The third parameter is the name of the database that was written to - 6751** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 6752** is the number of pages currently in the write-ahead log file, 6753** including those that were just committed. 6754** 6755** The callback function should normally return [SQLITE_OK]. ^If an error 6756** code is returned, that error will propagate back up through the 6757** SQLite code base to cause the statement that provoked the callback 6758** to report an error, though the commit will have still occurred. If the 6759** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 6760** that does not correspond to any valid SQLite error code, the results 6761** are undefined. 6762** 6763** A single database handle may have at most a single write-ahead log callback 6764** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 6765** previously registered write-ahead log callback. ^Note that the 6766** [sqlite3_wal_autocheckpoint()] interface and the 6767** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 6768** those overwrite any prior [sqlite3_wal_hook()] settings. 6769*/ 6770void *sqlite3_wal_hook( 6771 sqlite3*, 6772 int(*)(void *,sqlite3*,const char*,int), 6773 void* 6774); 6775 6776/* 6777** CAPI3REF: Configure an auto-checkpoint 6778** 6779** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 6780** [sqlite3_wal_hook()] that causes any database on [database connection] D 6781** to automatically [checkpoint] 6782** after committing a transaction if there are N or 6783** more frames in the [write-ahead log] file. ^Passing zero or 6784** a negative value as the nFrame parameter disables automatic 6785** checkpoints entirely. 6786** 6787** ^The callback registered by this function replaces any existing callback 6788** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 6789** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 6790** configured by this function. 6791** 6792** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 6793** from SQL. 6794** 6795** ^Every new [database connection] defaults to having the auto-checkpoint 6796** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 6797** pages. The use of this interface 6798** is only necessary if the default setting is found to be suboptimal 6799** for a particular application. 6800*/ 6801int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 6802 6803/* 6804** CAPI3REF: Checkpoint a database 6805** 6806** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 6807** on [database connection] D to be [checkpointed]. ^If X is NULL or an 6808** empty string, then a checkpoint is run on all databases of 6809** connection D. ^If the database connection D is not in 6810** [WAL | write-ahead log mode] then this interface is a harmless no-op. 6811** 6812** ^The [wal_checkpoint pragma] can be used to invoke this interface 6813** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 6814** [wal_autocheckpoint pragma] can be used to cause this interface to be 6815** run whenever the WAL reaches a certain size threshold. 6816** 6817** See also: [sqlite3_wal_checkpoint_v2()] 6818*/ 6819int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 6820 6821/* 6822** CAPI3REF: Checkpoint a database 6823** 6824** Run a checkpoint operation on WAL database zDb attached to database 6825** handle db. The specific operation is determined by the value of the 6826** eMode parameter: 6827** 6828** <dl> 6829** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 6830** Checkpoint as many frames as possible without waiting for any database 6831** readers or writers to finish. Sync the db file if all frames in the log 6832** are checkpointed. This mode is the same as calling 6833** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 6834** 6835** <dt>SQLITE_CHECKPOINT_FULL<dd> 6836** This mode blocks (calls the busy-handler callback) until there is no 6837** database writer and all readers are reading from the most recent database 6838** snapshot. It then checkpoints all frames in the log file and syncs the 6839** database file. This call blocks database writers while it is running, 6840** but not database readers. 6841** 6842** <dt>SQLITE_CHECKPOINT_RESTART<dd> 6843** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 6844** checkpointing the log file it blocks (calls the busy-handler callback) 6845** until all readers are reading from the database file only. This ensures 6846** that the next client to write to the database file restarts the log file 6847** from the beginning. This call blocks database writers while it is running, 6848** but not database readers. 6849** </dl> 6850** 6851** If pnLog is not NULL, then *pnLog is set to the total number of frames in 6852** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 6853** the total number of checkpointed frames (including any that were already 6854** checkpointed when this function is called). *pnLog and *pnCkpt may be 6855** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 6856** If no values are available because of an error, they are both set to -1 6857** before returning to communicate this to the caller. 6858** 6859** All calls obtain an exclusive "checkpoint" lock on the database file. If 6860** any other process is running a checkpoint operation at the same time, the 6861** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 6862** busy-handler configured, it will not be invoked in this case. 6863** 6864** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 6865** "writer" lock on the database file. If the writer lock cannot be obtained 6866** immediately, and a busy-handler is configured, it is invoked and the writer 6867** lock retried until either the busy-handler returns 0 or the lock is 6868** successfully obtained. The busy-handler is also invoked while waiting for 6869** database readers as described above. If the busy-handler returns 0 before 6870** the writer lock is obtained or while waiting for database readers, the 6871** checkpoint operation proceeds from that point in the same way as 6872** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 6873** without blocking any further. SQLITE_BUSY is returned in this case. 6874** 6875** If parameter zDb is NULL or points to a zero length string, then the 6876** specified operation is attempted on all WAL databases. In this case the 6877** values written to output parameters *pnLog and *pnCkpt are undefined. If 6878** an SQLITE_BUSY error is encountered when processing one or more of the 6879** attached WAL databases, the operation is still attempted on any remaining 6880** attached databases and SQLITE_BUSY is returned to the caller. If any other 6881** error occurs while processing an attached database, processing is abandoned 6882** and the error code returned to the caller immediately. If no error 6883** (SQLITE_BUSY or otherwise) is encountered while processing the attached 6884** databases, SQLITE_OK is returned. 6885** 6886** If database zDb is the name of an attached database that is not in WAL 6887** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 6888** zDb is not NULL (or a zero length string) and is not the name of any 6889** attached database, SQLITE_ERROR is returned to the caller. 6890*/ 6891int sqlite3_wal_checkpoint_v2( 6892 sqlite3 *db, /* Database handle */ 6893 const char *zDb, /* Name of attached database (or NULL) */ 6894 int eMode, /* SQLITE_CHECKPOINT_* value */ 6895 int *pnLog, /* OUT: Size of WAL log in frames */ 6896 int *pnCkpt /* OUT: Total number of frames checkpointed */ 6897); 6898 6899/* 6900** CAPI3REF: Checkpoint operation parameters 6901** 6902** These constants can be used as the 3rd parameter to 6903** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 6904** documentation for additional information about the meaning and use of 6905** each of these values. 6906*/ 6907#define SQLITE_CHECKPOINT_PASSIVE 0 6908#define SQLITE_CHECKPOINT_FULL 1 6909#define SQLITE_CHECKPOINT_RESTART 2 6910 6911/* 6912** CAPI3REF: Virtual Table Interface Configuration 6913** 6914** This function may be called by either the [xConnect] or [xCreate] method 6915** of a [virtual table] implementation to configure 6916** various facets of the virtual table interface. 6917** 6918** If this interface is invoked outside the context of an xConnect or 6919** xCreate virtual table method then the behavior is undefined. 6920** 6921** At present, there is only one option that may be configured using 6922** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 6923** may be added in the future. 6924*/ 6925int sqlite3_vtab_config(sqlite3*, int op, ...); 6926 6927/* 6928** CAPI3REF: Virtual Table Configuration Options 6929** 6930** These macros define the various options to the 6931** [sqlite3_vtab_config()] interface that [virtual table] implementations 6932** can use to customize and optimize their behavior. 6933** 6934** <dl> 6935** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 6936** <dd>Calls of the form 6937** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 6938** where X is an integer. If X is zero, then the [virtual table] whose 6939** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 6940** support constraints. In this configuration (which is the default) if 6941** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 6942** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 6943** specified as part of the users SQL statement, regardless of the actual 6944** ON CONFLICT mode specified. 6945** 6946** If X is non-zero, then the virtual table implementation guarantees 6947** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 6948** any modifications to internal or persistent data structures have been made. 6949** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 6950** is able to roll back a statement or database transaction, and abandon 6951** or continue processing the current SQL statement as appropriate. 6952** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 6953** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 6954** had been ABORT. 6955** 6956** Virtual table implementations that are required to handle OR REPLACE 6957** must do so within the [xUpdate] method. If a call to the 6958** [sqlite3_vtab_on_conflict()] function indicates that the current ON 6959** CONFLICT policy is REPLACE, the virtual table implementation should 6960** silently replace the appropriate rows within the xUpdate callback and 6961** return SQLITE_OK. Or, if this is not possible, it may return 6962** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 6963** constraint handling. 6964** </dl> 6965*/ 6966#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 6967 6968/* 6969** CAPI3REF: Determine The Virtual Table Conflict Policy 6970** 6971** This function may only be called from within a call to the [xUpdate] method 6972** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 6973** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 6974** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 6975** of the SQL statement that triggered the call to the [xUpdate] method of the 6976** [virtual table]. 6977*/ 6978int sqlite3_vtab_on_conflict(sqlite3 *); 6979 6980/* 6981** CAPI3REF: Conflict resolution modes 6982** 6983** These constants are returned by [sqlite3_vtab_on_conflict()] to 6984** inform a [virtual table] implementation what the [ON CONFLICT] mode 6985** is for the SQL statement being evaluated. 6986** 6987** Note that the [SQLITE_IGNORE] constant is also used as a potential 6988** return value from the [sqlite3_set_authorizer()] callback and that 6989** [SQLITE_ABORT] is also a [result code]. 6990*/ 6991#define SQLITE_ROLLBACK 1 6992/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 6993#define SQLITE_FAIL 3 6994/* #define SQLITE_ABORT 4 // Also an error code */ 6995#define SQLITE_REPLACE 5 6996 6997 6998 6999/* 7000** Undo the hack that converts floating point types to integer for 7001** builds on processors without floating point support. 7002*/ 7003#ifdef SQLITE_OMIT_FLOATING_POINT 7004# undef double 7005#endif 7006 7007#ifdef __cplusplus 7008} /* End of the 'extern "C"' block */ 7009#endif 7010#endif 7011