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_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 477#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 478#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 479#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 480#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 481 482/* 483** CAPI3REF: Flags For File Open Operations 484** 485** These bit values are intended for use in the 486** 3rd parameter to the [sqlite3_open_v2()] interface and 487** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 488*/ 489#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 490#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 491#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 492#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 493#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 494#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 495#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 496#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 497#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 498#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 499#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 500#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 501#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 502#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 503#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 504#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 505#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 506#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 507#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 508#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 509 510/* Reserved: 0x00F00000 */ 511 512/* 513** CAPI3REF: Device Characteristics 514** 515** The xDeviceCharacteristics method of the [sqlite3_io_methods] 516** object returns an integer which is a vector of these 517** bit values expressing I/O characteristics of the mass storage 518** device that holds the file that the [sqlite3_io_methods] 519** refers to. 520** 521** The SQLITE_IOCAP_ATOMIC property means that all writes of 522** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 523** mean that writes of blocks that are nnn bytes in size and 524** are aligned to an address which is an integer multiple of 525** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 526** that when data is appended to a file, the data is appended 527** first then the size of the file is extended, never the other 528** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 529** information is written to disk in the same order as calls 530** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 531** after reboot following a crash or power loss, the only bytes in a 532** file that were written at the application level might have changed 533** and that adjacent bytes, even bytes within the same sector are 534** guaranteed to be unchanged. 535*/ 536#define SQLITE_IOCAP_ATOMIC 0x00000001 537#define SQLITE_IOCAP_ATOMIC512 0x00000002 538#define SQLITE_IOCAP_ATOMIC1K 0x00000004 539#define SQLITE_IOCAP_ATOMIC2K 0x00000008 540#define SQLITE_IOCAP_ATOMIC4K 0x00000010 541#define SQLITE_IOCAP_ATOMIC8K 0x00000020 542#define SQLITE_IOCAP_ATOMIC16K 0x00000040 543#define SQLITE_IOCAP_ATOMIC32K 0x00000080 544#define SQLITE_IOCAP_ATOMIC64K 0x00000100 545#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 546#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 547#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 548#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 549 550/* 551** CAPI3REF: File Locking Levels 552** 553** SQLite uses one of these integer values as the second 554** argument to calls it makes to the xLock() and xUnlock() methods 555** of an [sqlite3_io_methods] object. 556*/ 557#define SQLITE_LOCK_NONE 0 558#define SQLITE_LOCK_SHARED 1 559#define SQLITE_LOCK_RESERVED 2 560#define SQLITE_LOCK_PENDING 3 561#define SQLITE_LOCK_EXCLUSIVE 4 562 563/* 564** CAPI3REF: Synchronization Type Flags 565** 566** When SQLite invokes the xSync() method of an 567** [sqlite3_io_methods] object it uses a combination of 568** these integer values as the second argument. 569** 570** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 571** sync operation only needs to flush data to mass storage. Inode 572** information need not be flushed. If the lower four bits of the flag 573** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 574** If the lower four bits equal SQLITE_SYNC_FULL, that means 575** to use Mac OS X style fullsync instead of fsync(). 576** 577** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 578** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 579** settings. The [synchronous pragma] determines when calls to the 580** xSync VFS method occur and applies uniformly across all platforms. 581** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 582** energetic or rigorous or forceful the sync operations are and 583** only make a difference on Mac OSX for the default SQLite code. 584** (Third-party VFS implementations might also make the distinction 585** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 586** operating systems natively supported by SQLite, only Mac OSX 587** cares about the difference.) 588*/ 589#define SQLITE_SYNC_NORMAL 0x00002 590#define SQLITE_SYNC_FULL 0x00003 591#define SQLITE_SYNC_DATAONLY 0x00010 592 593/* 594** CAPI3REF: OS Interface Open File Handle 595** 596** An [sqlite3_file] object represents an open file in the 597** [sqlite3_vfs | OS interface layer]. Individual OS interface 598** implementations will 599** want to subclass this object by appending additional fields 600** for their own use. The pMethods entry is a pointer to an 601** [sqlite3_io_methods] object that defines methods for performing 602** I/O operations on the open file. 603*/ 604typedef struct sqlite3_file sqlite3_file; 605struct sqlite3_file { 606 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 607}; 608 609/* 610** CAPI3REF: OS Interface File Virtual Methods Object 611** 612** Every file opened by the [sqlite3_vfs.xOpen] method populates an 613** [sqlite3_file] object (or, more commonly, a subclass of the 614** [sqlite3_file] object) with a pointer to an instance of this object. 615** This object defines the methods used to perform various operations 616** against the open file represented by the [sqlite3_file] object. 617** 618** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 619** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 620** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 621** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 622** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 623** to NULL. 624** 625** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 626** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 627** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 628** flag may be ORed in to indicate that only the data of the file 629** and not its inode needs to be synced. 630** 631** The integer values to xLock() and xUnlock() are one of 632** <ul> 633** <li> [SQLITE_LOCK_NONE], 634** <li> [SQLITE_LOCK_SHARED], 635** <li> [SQLITE_LOCK_RESERVED], 636** <li> [SQLITE_LOCK_PENDING], or 637** <li> [SQLITE_LOCK_EXCLUSIVE]. 638** </ul> 639** xLock() increases the lock. xUnlock() decreases the lock. 640** The xCheckReservedLock() method checks whether any database connection, 641** either in this process or in some other process, is holding a RESERVED, 642** PENDING, or EXCLUSIVE lock on the file. It returns true 643** if such a lock exists and false otherwise. 644** 645** The xFileControl() method is a generic interface that allows custom 646** VFS implementations to directly control an open file using the 647** [sqlite3_file_control()] interface. The second "op" argument is an 648** integer opcode. The third argument is a generic pointer intended to 649** point to a structure that may contain arguments or space in which to 650** write return values. Potential uses for xFileControl() might be 651** functions to enable blocking locks with timeouts, to change the 652** locking strategy (for example to use dot-file locks), to inquire 653** about the status of a lock, or to break stale locks. The SQLite 654** core reserves all opcodes less than 100 for its own use. 655** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 656** Applications that define a custom xFileControl method should use opcodes 657** greater than 100 to avoid conflicts. VFS implementations should 658** return [SQLITE_NOTFOUND] for file control opcodes that they do not 659** recognize. 660** 661** The xSectorSize() method returns the sector size of the 662** device that underlies the file. The sector size is the 663** minimum write that can be performed without disturbing 664** other bytes in the file. The xDeviceCharacteristics() 665** method returns a bit vector describing behaviors of the 666** underlying device: 667** 668** <ul> 669** <li> [SQLITE_IOCAP_ATOMIC] 670** <li> [SQLITE_IOCAP_ATOMIC512] 671** <li> [SQLITE_IOCAP_ATOMIC1K] 672** <li> [SQLITE_IOCAP_ATOMIC2K] 673** <li> [SQLITE_IOCAP_ATOMIC4K] 674** <li> [SQLITE_IOCAP_ATOMIC8K] 675** <li> [SQLITE_IOCAP_ATOMIC16K] 676** <li> [SQLITE_IOCAP_ATOMIC32K] 677** <li> [SQLITE_IOCAP_ATOMIC64K] 678** <li> [SQLITE_IOCAP_SAFE_APPEND] 679** <li> [SQLITE_IOCAP_SEQUENTIAL] 680** </ul> 681** 682** The SQLITE_IOCAP_ATOMIC property means that all writes of 683** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 684** mean that writes of blocks that are nnn bytes in size and 685** are aligned to an address which is an integer multiple of 686** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 687** that when data is appended to a file, the data is appended 688** first then the size of the file is extended, never the other 689** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 690** information is written to disk in the same order as calls 691** to xWrite(). 692** 693** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 694** in the unread portions of the buffer with zeros. A VFS that 695** fails to zero-fill short reads might seem to work. However, 696** failure to zero-fill short reads will eventually lead to 697** database corruption. 698*/ 699typedef struct sqlite3_io_methods sqlite3_io_methods; 700struct sqlite3_io_methods { 701 int iVersion; 702 int (*xClose)(sqlite3_file*); 703 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 704 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 705 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 706 int (*xSync)(sqlite3_file*, int flags); 707 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 708 int (*xLock)(sqlite3_file*, int); 709 int (*xUnlock)(sqlite3_file*, int); 710 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 711 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 712 int (*xSectorSize)(sqlite3_file*); 713 int (*xDeviceCharacteristics)(sqlite3_file*); 714 /* Methods above are valid for version 1 */ 715 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 716 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 717 void (*xShmBarrier)(sqlite3_file*); 718 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 719 /* Methods above are valid for version 2 */ 720 /* Additional methods may be added in future releases */ 721}; 722 723/* 724** CAPI3REF: Standard File Control Opcodes 725** 726** These integer constants are opcodes for the xFileControl method 727** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 728** interface. 729** 730** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 731** opcode causes the xFileControl method to write the current state of 732** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 733** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 734** into an integer that the pArg argument points to. This capability 735** is used during testing and only needs to be supported when SQLITE_TEST 736** is defined. 737** <ul> 738** <li>[[SQLITE_FCNTL_SIZE_HINT]] 739** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 740** layer a hint of how large the database file will grow to be during the 741** current transaction. This hint is not guaranteed to be accurate but it 742** is often close. The underlying VFS might choose to preallocate database 743** file space based on this hint in order to help writes to the database 744** file run faster. 745** 746** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 747** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 748** extends and truncates the database file in chunks of a size specified 749** by the user. The fourth argument to [sqlite3_file_control()] should 750** point to an integer (type int) containing the new chunk-size to use 751** for the nominated database. Allocating database file space in large 752** chunks (say 1MB at a time), may reduce file-system fragmentation and 753** improve performance on some systems. 754** 755** <li>[[SQLITE_FCNTL_FILE_POINTER]] 756** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 757** to the [sqlite3_file] object associated with a particular database 758** connection. See the [sqlite3_file_control()] documentation for 759** additional information. 760** 761** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 762** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by 763** SQLite and sent to all VFSes in place of a call to the xSync method 764** when the database connection has [PRAGMA synchronous] set to OFF.)^ 765** Some specialized VFSes need this signal in order to operate correctly 766** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 767** VFSes do not need this signal and should silently ignore this opcode. 768** Applications should not call [sqlite3_file_control()] with this 769** opcode as doing so may disrupt the operation of the specialized VFSes 770** that do require it. 771** 772** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 773** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 774** retry counts and intervals for certain disk I/O operations for the 775** windows [VFS] in order to provide robustness in the presence of 776** anti-virus programs. By default, the windows VFS will retry file read, 777** file write, and file delete operations up to 10 times, with a delay 778** of 25 milliseconds before the first retry and with the delay increasing 779** by an additional 25 milliseconds with each subsequent retry. This 780** opcode allows these two values (10 retries and 25 milliseconds of delay) 781** to be adjusted. The values are changed for all database connections 782** within the same process. The argument is a pointer to an array of two 783** integers where the first integer i the new retry count and the second 784** integer is the delay. If either integer is negative, then the setting 785** is not changed but instead the prior value of that setting is written 786** into the array entry, allowing the current retry settings to be 787** interrogated. The zDbName parameter is ignored. 788** 789** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 790** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 791** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 792** write ahead log and shared memory files used for transaction control 793** are automatically deleted when the latest connection to the database 794** closes. Setting persistent WAL mode causes those files to persist after 795** close. Persisting the files is useful when other processes that do not 796** have write permission on the directory containing the database file want 797** to read the database file, as the WAL and shared memory files must exist 798** in order for the database to be readable. The fourth parameter to 799** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 800** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 801** WAL mode. If the integer is -1, then it is overwritten with the current 802** WAL persistence setting. 803** 804** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 805** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 806** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 807** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 808** xDeviceCharacteristics methods. The fourth parameter to 809** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 810** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 811** mode. If the integer is -1, then it is overwritten with the current 812** zero-damage mode setting. 813** 814** <li>[[SQLITE_FCNTL_OVERWRITE]] 815** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 816** a write transaction to indicate that, unless it is rolled back for some 817** reason, the entire database file will be overwritten by the current 818** transaction. This is used by VACUUM operations. 819** 820** <li>[[SQLITE_FCNTL_VFSNAME]] 821** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 822** all [VFSes] in the VFS stack. The names are of all VFS shims and the 823** final bottom-level VFS are written into memory obtained from 824** [sqlite3_malloc()] and the result is stored in the char* variable 825** that the fourth parameter of [sqlite3_file_control()] points to. 826** The caller is responsible for freeing the memory when done. As with 827** all file-control actions, there is no guarantee that this will actually 828** do anything. Callers should initialize the char* variable to a NULL 829** pointer in case this file-control is not implemented. This file-control 830** is intended for diagnostic use only. 831** 832** <li>[[SQLITE_FCNTL_PRAGMA]] 833** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 834** file control is sent to the open [sqlite3_file] object corresponding 835** to the database file to which the pragma statement refers. ^The argument 836** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 837** pointers to strings (char**) in which the second element of the array 838** is the name of the pragma and the third element is the argument to the 839** pragma or NULL if the pragma has no argument. ^The handler for an 840** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 841** of the char** argument point to a string obtained from [sqlite3_mprintf()] 842** or the equivalent and that string will become the result of the pragma or 843** the error message if the pragma fails. ^If the 844** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 845** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 846** file control returns [SQLITE_OK], then the parser assumes that the 847** VFS has handled the PRAGMA itself and the parser generates a no-op 848** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns 849** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 850** that the VFS encountered an error while handling the [PRAGMA] and the 851** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 852** file control occurs at the beginning of pragma statement analysis and so 853** it is able to override built-in [PRAGMA] statements. 854** </ul> 855** 856** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 857** ^This file-control may be invoked by SQLite on the database file handle 858** shortly after it is opened in order to provide a custom VFS with access 859** to the connections busy-handler callback. The argument is of type (void **) 860** - an array of two (void *) values. The first (void *) actually points 861** to a function of type (int (*)(void *)). In order to invoke the connections 862** busy-handler, this function should be invoked with the second (void *) in 863** the array as the only argument. If it returns non-zero, then the operation 864** should be retried. If it returns zero, the custom VFS should abandon the 865** current operation. 866*/ 867#define SQLITE_FCNTL_LOCKSTATE 1 868#define SQLITE_GET_LOCKPROXYFILE 2 869#define SQLITE_SET_LOCKPROXYFILE 3 870#define SQLITE_LAST_ERRNO 4 871#define SQLITE_FCNTL_SIZE_HINT 5 872#define SQLITE_FCNTL_CHUNK_SIZE 6 873#define SQLITE_FCNTL_FILE_POINTER 7 874#define SQLITE_FCNTL_SYNC_OMITTED 8 875#define SQLITE_FCNTL_WIN32_AV_RETRY 9 876#define SQLITE_FCNTL_PERSIST_WAL 10 877#define SQLITE_FCNTL_OVERWRITE 11 878#define SQLITE_FCNTL_VFSNAME 12 879#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 880#define SQLITE_FCNTL_PRAGMA 14 881#define SQLITE_FCNTL_BUSYHANDLER 15 882 883/* 884** CAPI3REF: Mutex Handle 885** 886** The mutex module within SQLite defines [sqlite3_mutex] to be an 887** abstract type for a mutex object. The SQLite core never looks 888** at the internal representation of an [sqlite3_mutex]. It only 889** deals with pointers to the [sqlite3_mutex] object. 890** 891** Mutexes are created using [sqlite3_mutex_alloc()]. 892*/ 893typedef struct sqlite3_mutex sqlite3_mutex; 894 895/* 896** CAPI3REF: OS Interface Object 897** 898** An instance of the sqlite3_vfs object defines the interface between 899** the SQLite core and the underlying operating system. The "vfs" 900** in the name of the object stands for "virtual file system". See 901** the [VFS | VFS documentation] for further information. 902** 903** The value of the iVersion field is initially 1 but may be larger in 904** future versions of SQLite. Additional fields may be appended to this 905** object when the iVersion value is increased. Note that the structure 906** of the sqlite3_vfs object changes in the transaction between 907** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 908** modified. 909** 910** The szOsFile field is the size of the subclassed [sqlite3_file] 911** structure used by this VFS. mxPathname is the maximum length of 912** a pathname in this VFS. 913** 914** Registered sqlite3_vfs objects are kept on a linked list formed by 915** the pNext pointer. The [sqlite3_vfs_register()] 916** and [sqlite3_vfs_unregister()] interfaces manage this list 917** in a thread-safe way. The [sqlite3_vfs_find()] interface 918** searches the list. Neither the application code nor the VFS 919** implementation should use the pNext pointer. 920** 921** The pNext field is the only field in the sqlite3_vfs 922** structure that SQLite will ever modify. SQLite will only access 923** or modify this field while holding a particular static mutex. 924** The application should never modify anything within the sqlite3_vfs 925** object once the object has been registered. 926** 927** The zName field holds the name of the VFS module. The name must 928** be unique across all VFS modules. 929** 930** [[sqlite3_vfs.xOpen]] 931** ^SQLite guarantees that the zFilename parameter to xOpen 932** is either a NULL pointer or string obtained 933** from xFullPathname() with an optional suffix added. 934** ^If a suffix is added to the zFilename parameter, it will 935** consist of a single "-" character followed by no more than 936** 11 alphanumeric and/or "-" characters. 937** ^SQLite further guarantees that 938** the string will be valid and unchanged until xClose() is 939** called. Because of the previous sentence, 940** the [sqlite3_file] can safely store a pointer to the 941** filename if it needs to remember the filename for some reason. 942** If the zFilename parameter to xOpen is a NULL pointer then xOpen 943** must invent its own temporary name for the file. ^Whenever the 944** xFilename parameter is NULL it will also be the case that the 945** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 946** 947** The flags argument to xOpen() includes all bits set in 948** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 949** or [sqlite3_open16()] is used, then flags includes at least 950** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 951** If xOpen() opens a file read-only then it sets *pOutFlags to 952** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 953** 954** ^(SQLite will also add one of the following flags to the xOpen() 955** call, depending on the object being opened: 956** 957** <ul> 958** <li> [SQLITE_OPEN_MAIN_DB] 959** <li> [SQLITE_OPEN_MAIN_JOURNAL] 960** <li> [SQLITE_OPEN_TEMP_DB] 961** <li> [SQLITE_OPEN_TEMP_JOURNAL] 962** <li> [SQLITE_OPEN_TRANSIENT_DB] 963** <li> [SQLITE_OPEN_SUBJOURNAL] 964** <li> [SQLITE_OPEN_MASTER_JOURNAL] 965** <li> [SQLITE_OPEN_WAL] 966** </ul>)^ 967** 968** The file I/O implementation can use the object type flags to 969** change the way it deals with files. For example, an application 970** that does not care about crash recovery or rollback might make 971** the open of a journal file a no-op. Writes to this journal would 972** also be no-ops, and any attempt to read the journal would return 973** SQLITE_IOERR. Or the implementation might recognize that a database 974** file will be doing page-aligned sector reads and writes in a random 975** order and set up its I/O subsystem accordingly. 976** 977** SQLite might also add one of the following flags to the xOpen method: 978** 979** <ul> 980** <li> [SQLITE_OPEN_DELETEONCLOSE] 981** <li> [SQLITE_OPEN_EXCLUSIVE] 982** </ul> 983** 984** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 985** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 986** will be set for TEMP databases and their journals, transient 987** databases, and subjournals. 988** 989** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 990** with the [SQLITE_OPEN_CREATE] flag, which are both directly 991** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 992** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 993** SQLITE_OPEN_CREATE, is used to indicate that file should always 994** be created, and that it is an error if it already exists. 995** It is <i>not</i> used to indicate the file should be opened 996** for exclusive access. 997** 998** ^At least szOsFile bytes of memory are allocated by SQLite 999** to hold the [sqlite3_file] structure passed as the third 1000** argument to xOpen. The xOpen method does not have to 1001** allocate the structure; it should just fill it in. Note that 1002** the xOpen method must set the sqlite3_file.pMethods to either 1003** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1004** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1005** element will be valid after xOpen returns regardless of the success 1006** or failure of the xOpen call. 1007** 1008** [[sqlite3_vfs.xAccess]] 1009** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1010** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1011** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1012** to test whether a file is at least readable. The file can be a 1013** directory. 1014** 1015** ^SQLite will always allocate at least mxPathname+1 bytes for the 1016** output buffer xFullPathname. The exact size of the output buffer 1017** is also passed as a parameter to both methods. If the output buffer 1018** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1019** handled as a fatal error by SQLite, vfs implementations should endeavor 1020** to prevent this by setting mxPathname to a sufficiently large value. 1021** 1022** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1023** interfaces are not strictly a part of the filesystem, but they are 1024** included in the VFS structure for completeness. 1025** The xRandomness() function attempts to return nBytes bytes 1026** of good-quality randomness into zOut. The return value is 1027** the actual number of bytes of randomness obtained. 1028** The xSleep() method causes the calling thread to sleep for at 1029** least the number of microseconds given. ^The xCurrentTime() 1030** method returns a Julian Day Number for the current date and time as 1031** a floating point value. 1032** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1033** Day Number multiplied by 86400000 (the number of milliseconds in 1034** a 24-hour day). 1035** ^SQLite will use the xCurrentTimeInt64() method to get the current 1036** date and time if that method is available (if iVersion is 2 or 1037** greater and the function pointer is not NULL) and will fall back 1038** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1039** 1040** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1041** are not used by the SQLite core. These optional interfaces are provided 1042** by some VFSes to facilitate testing of the VFS code. By overriding 1043** system calls with functions under its control, a test program can 1044** simulate faults and error conditions that would otherwise be difficult 1045** or impossible to induce. The set of system calls that can be overridden 1046** varies from one VFS to another, and from one version of the same VFS to the 1047** next. Applications that use these interfaces must be prepared for any 1048** or all of these interfaces to be NULL or for their behavior to change 1049** from one release to the next. Applications must not attempt to access 1050** any of these methods if the iVersion of the VFS is less than 3. 1051*/ 1052typedef struct sqlite3_vfs sqlite3_vfs; 1053typedef void (*sqlite3_syscall_ptr)(void); 1054struct sqlite3_vfs { 1055 int iVersion; /* Structure version number (currently 3) */ 1056 int szOsFile; /* Size of subclassed sqlite3_file */ 1057 int mxPathname; /* Maximum file pathname length */ 1058 sqlite3_vfs *pNext; /* Next registered VFS */ 1059 const char *zName; /* Name of this virtual file system */ 1060 void *pAppData; /* Pointer to application-specific data */ 1061 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1062 int flags, int *pOutFlags); 1063 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1064 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1065 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1066 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1067 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1068 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1069 void (*xDlClose)(sqlite3_vfs*, void*); 1070 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1071 int (*xSleep)(sqlite3_vfs*, int microseconds); 1072 int (*xCurrentTime)(sqlite3_vfs*, double*); 1073 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1074 /* 1075 ** The methods above are in version 1 of the sqlite_vfs object 1076 ** definition. Those that follow are added in version 2 or later 1077 */ 1078 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1079 /* 1080 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1081 ** Those below are for version 3 and greater. 1082 */ 1083 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1084 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1085 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1086 /* 1087 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1088 ** New fields may be appended in figure versions. The iVersion 1089 ** value will increment whenever this happens. 1090 */ 1091}; 1092 1093/* 1094** CAPI3REF: Flags for the xAccess VFS method 1095** 1096** These integer constants can be used as the third parameter to 1097** the xAccess method of an [sqlite3_vfs] object. They determine 1098** what kind of permissions the xAccess method is looking for. 1099** With SQLITE_ACCESS_EXISTS, the xAccess method 1100** simply checks whether the file exists. 1101** With SQLITE_ACCESS_READWRITE, the xAccess method 1102** checks whether the named directory is both readable and writable 1103** (in other words, if files can be added, removed, and renamed within 1104** the directory). 1105** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1106** [temp_store_directory pragma], though this could change in a future 1107** release of SQLite. 1108** With SQLITE_ACCESS_READ, the xAccess method 1109** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1110** currently unused, though it might be used in a future release of 1111** SQLite. 1112*/ 1113#define SQLITE_ACCESS_EXISTS 0 1114#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1115#define SQLITE_ACCESS_READ 2 /* Unused */ 1116 1117/* 1118** CAPI3REF: Flags for the xShmLock VFS method 1119** 1120** These integer constants define the various locking operations 1121** allowed by the xShmLock method of [sqlite3_io_methods]. The 1122** following are the only legal combinations of flags to the 1123** xShmLock method: 1124** 1125** <ul> 1126** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1127** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1128** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1129** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1130** </ul> 1131** 1132** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1133** was given no the corresponding lock. 1134** 1135** The xShmLock method can transition between unlocked and SHARED or 1136** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1137** and EXCLUSIVE. 1138*/ 1139#define SQLITE_SHM_UNLOCK 1 1140#define SQLITE_SHM_LOCK 2 1141#define SQLITE_SHM_SHARED 4 1142#define SQLITE_SHM_EXCLUSIVE 8 1143 1144/* 1145** CAPI3REF: Maximum xShmLock index 1146** 1147** The xShmLock method on [sqlite3_io_methods] may use values 1148** between 0 and this upper bound as its "offset" argument. 1149** The SQLite core will never attempt to acquire or release a 1150** lock outside of this range 1151*/ 1152#define SQLITE_SHM_NLOCK 8 1153 1154 1155/* 1156** CAPI3REF: Initialize The SQLite Library 1157** 1158** ^The sqlite3_initialize() routine initializes the 1159** SQLite library. ^The sqlite3_shutdown() routine 1160** deallocates any resources that were allocated by sqlite3_initialize(). 1161** These routines are designed to aid in process initialization and 1162** shutdown on embedded systems. Workstation applications using 1163** SQLite normally do not need to invoke either of these routines. 1164** 1165** A call to sqlite3_initialize() is an "effective" call if it is 1166** the first time sqlite3_initialize() is invoked during the lifetime of 1167** the process, or if it is the first time sqlite3_initialize() is invoked 1168** following a call to sqlite3_shutdown(). ^(Only an effective call 1169** of sqlite3_initialize() does any initialization. All other calls 1170** are harmless no-ops.)^ 1171** 1172** A call to sqlite3_shutdown() is an "effective" call if it is the first 1173** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1174** an effective call to sqlite3_shutdown() does any deinitialization. 1175** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1176** 1177** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1178** is not. The sqlite3_shutdown() interface must only be called from a 1179** single thread. All open [database connections] must be closed and all 1180** other SQLite resources must be deallocated prior to invoking 1181** sqlite3_shutdown(). 1182** 1183** Among other things, ^sqlite3_initialize() will invoke 1184** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1185** will invoke sqlite3_os_end(). 1186** 1187** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1188** ^If for some reason, sqlite3_initialize() is unable to initialize 1189** the library (perhaps it is unable to allocate a needed resource such 1190** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1191** 1192** ^The sqlite3_initialize() routine is called internally by many other 1193** SQLite interfaces so that an application usually does not need to 1194** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1195** calls sqlite3_initialize() so the SQLite library will be automatically 1196** initialized when [sqlite3_open()] is called if it has not be initialized 1197** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1198** compile-time option, then the automatic calls to sqlite3_initialize() 1199** are omitted and the application must call sqlite3_initialize() directly 1200** prior to using any other SQLite interface. For maximum portability, 1201** it is recommended that applications always invoke sqlite3_initialize() 1202** directly prior to using any other SQLite interface. Future releases 1203** of SQLite may require this. In other words, the behavior exhibited 1204** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1205** default behavior in some future release of SQLite. 1206** 1207** The sqlite3_os_init() routine does operating-system specific 1208** initialization of the SQLite library. The sqlite3_os_end() 1209** routine undoes the effect of sqlite3_os_init(). Typical tasks 1210** performed by these routines include allocation or deallocation 1211** of static resources, initialization of global variables, 1212** setting up a default [sqlite3_vfs] module, or setting up 1213** a default configuration using [sqlite3_config()]. 1214** 1215** The application should never invoke either sqlite3_os_init() 1216** or sqlite3_os_end() directly. The application should only invoke 1217** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1218** interface is called automatically by sqlite3_initialize() and 1219** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1220** implementations for sqlite3_os_init() and sqlite3_os_end() 1221** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1222** When [custom builds | built for other platforms] 1223** (using the [SQLITE_OS_OTHER=1] compile-time 1224** option) the application must supply a suitable implementation for 1225** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1226** implementation of sqlite3_os_init() or sqlite3_os_end() 1227** must return [SQLITE_OK] on success and some other [error code] upon 1228** failure. 1229*/ 1230int sqlite3_initialize(void); 1231int sqlite3_shutdown(void); 1232int sqlite3_os_init(void); 1233int sqlite3_os_end(void); 1234 1235/* 1236** CAPI3REF: Configuring The SQLite Library 1237** 1238** The sqlite3_config() interface is used to make global configuration 1239** changes to SQLite in order to tune SQLite to the specific needs of 1240** the application. The default configuration is recommended for most 1241** applications and so this routine is usually not necessary. It is 1242** provided to support rare applications with unusual needs. 1243** 1244** The sqlite3_config() interface is not threadsafe. The application 1245** must insure that no other SQLite interfaces are invoked by other 1246** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1247** may only be invoked prior to library initialization using 1248** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1249** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1250** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1251** Note, however, that ^sqlite3_config() can be called as part of the 1252** implementation of an application-defined [sqlite3_os_init()]. 1253** 1254** The first argument to sqlite3_config() is an integer 1255** [configuration option] that determines 1256** what property of SQLite is to be configured. Subsequent arguments 1257** vary depending on the [configuration option] 1258** in the first argument. 1259** 1260** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1261** ^If the option is unknown or SQLite is unable to set the option 1262** then this routine returns a non-zero [error code]. 1263*/ 1264int sqlite3_config(int, ...); 1265 1266/* 1267** CAPI3REF: Configure database connections 1268** 1269** The sqlite3_db_config() interface is used to make configuration 1270** changes to a [database connection]. The interface is similar to 1271** [sqlite3_config()] except that the changes apply to a single 1272** [database connection] (specified in the first argument). 1273** 1274** The second argument to sqlite3_db_config(D,V,...) is the 1275** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1276** that indicates what aspect of the [database connection] is being configured. 1277** Subsequent arguments vary depending on the configuration verb. 1278** 1279** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1280** the call is considered successful. 1281*/ 1282int sqlite3_db_config(sqlite3*, int op, ...); 1283 1284/* 1285** CAPI3REF: Memory Allocation Routines 1286** 1287** An instance of this object defines the interface between SQLite 1288** and low-level memory allocation routines. 1289** 1290** This object is used in only one place in the SQLite interface. 1291** A pointer to an instance of this object is the argument to 1292** [sqlite3_config()] when the configuration option is 1293** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1294** By creating an instance of this object 1295** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1296** during configuration, an application can specify an alternative 1297** memory allocation subsystem for SQLite to use for all of its 1298** dynamic memory needs. 1299** 1300** Note that SQLite comes with several [built-in memory allocators] 1301** that are perfectly adequate for the overwhelming majority of applications 1302** and that this object is only useful to a tiny minority of applications 1303** with specialized memory allocation requirements. This object is 1304** also used during testing of SQLite in order to specify an alternative 1305** memory allocator that simulates memory out-of-memory conditions in 1306** order to verify that SQLite recovers gracefully from such 1307** conditions. 1308** 1309** The xMalloc, xRealloc, and xFree methods must work like the 1310** malloc(), realloc() and free() functions from the standard C library. 1311** ^SQLite guarantees that the second argument to 1312** xRealloc is always a value returned by a prior call to xRoundup. 1313** 1314** xSize should return the allocated size of a memory allocation 1315** previously obtained from xMalloc or xRealloc. The allocated size 1316** is always at least as big as the requested size but may be larger. 1317** 1318** The xRoundup method returns what would be the allocated size of 1319** a memory allocation given a particular requested size. Most memory 1320** allocators round up memory allocations at least to the next multiple 1321** of 8. Some allocators round up to a larger multiple or to a power of 2. 1322** Every memory allocation request coming in through [sqlite3_malloc()] 1323** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1324** that causes the corresponding memory allocation to fail. 1325** 1326** The xInit method initializes the memory allocator. (For example, 1327** it might allocate any require mutexes or initialize internal data 1328** structures. The xShutdown method is invoked (indirectly) by 1329** [sqlite3_shutdown()] and should deallocate any resources acquired 1330** by xInit. The pAppData pointer is used as the only parameter to 1331** xInit and xShutdown. 1332** 1333** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1334** the xInit method, so the xInit method need not be threadsafe. The 1335** xShutdown method is only called from [sqlite3_shutdown()] so it does 1336** not need to be threadsafe either. For all other methods, SQLite 1337** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1338** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1339** it is by default) and so the methods are automatically serialized. 1340** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1341** methods must be threadsafe or else make their own arrangements for 1342** serialization. 1343** 1344** SQLite will never invoke xInit() more than once without an intervening 1345** call to xShutdown(). 1346*/ 1347typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1348struct sqlite3_mem_methods { 1349 void *(*xMalloc)(int); /* Memory allocation function */ 1350 void (*xFree)(void*); /* Free a prior allocation */ 1351 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1352 int (*xSize)(void*); /* Return the size of an allocation */ 1353 int (*xRoundup)(int); /* Round up request size to allocation size */ 1354 int (*xInit)(void*); /* Initialize the memory allocator */ 1355 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1356 void *pAppData; /* Argument to xInit() and xShutdown() */ 1357}; 1358 1359/* 1360** CAPI3REF: Configuration Options 1361** KEYWORDS: {configuration option} 1362** 1363** These constants are the available integer configuration options that 1364** can be passed as the first argument to the [sqlite3_config()] interface. 1365** 1366** New configuration options may be added in future releases of SQLite. 1367** Existing configuration options might be discontinued. Applications 1368** should check the return code from [sqlite3_config()] to make sure that 1369** the call worked. The [sqlite3_config()] interface will return a 1370** non-zero [error code] if a discontinued or unsupported configuration option 1371** is invoked. 1372** 1373** <dl> 1374** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1375** <dd>There are no arguments to this option. ^This option sets the 1376** [threading mode] to Single-thread. In other words, it disables 1377** all mutexing and puts SQLite into a mode where it can only be used 1378** by a single thread. ^If SQLite is compiled with 1379** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1380** it is not possible to change the [threading mode] from its default 1381** value of Single-thread and so [sqlite3_config()] will return 1382** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1383** configuration option.</dd> 1384** 1385** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1386** <dd>There are no arguments to this option. ^This option sets the 1387** [threading mode] to Multi-thread. In other words, it disables 1388** mutexing on [database connection] and [prepared statement] objects. 1389** The application is responsible for serializing access to 1390** [database connections] and [prepared statements]. But other mutexes 1391** are enabled so that SQLite will be safe to use in a multi-threaded 1392** environment as long as no two threads attempt to use the same 1393** [database connection] at the same time. ^If SQLite is compiled with 1394** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1395** it is not possible to set the Multi-thread [threading mode] and 1396** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1397** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1398** 1399** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1400** <dd>There are no arguments to this option. ^This option sets the 1401** [threading mode] to Serialized. In other words, this option enables 1402** all mutexes including the recursive 1403** mutexes on [database connection] and [prepared statement] objects. 1404** In this mode (which is the default when SQLite is compiled with 1405** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1406** to [database connections] and [prepared statements] so that the 1407** application is free to use the same [database connection] or the 1408** same [prepared statement] in different threads at the same time. 1409** ^If SQLite is compiled with 1410** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1411** it is not possible to set the Serialized [threading mode] and 1412** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1413** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1414** 1415** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1416** <dd> ^(This option takes a single argument which is a pointer to an 1417** instance of the [sqlite3_mem_methods] structure. The argument specifies 1418** alternative low-level memory allocation routines to be used in place of 1419** the memory allocation routines built into SQLite.)^ ^SQLite makes 1420** its own private copy of the content of the [sqlite3_mem_methods] structure 1421** before the [sqlite3_config()] call returns.</dd> 1422** 1423** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1424** <dd> ^(This option takes a single argument which is a pointer to an 1425** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1426** structure is filled with the currently defined memory allocation routines.)^ 1427** This option can be used to overload the default memory allocation 1428** routines with a wrapper that simulations memory allocation failure or 1429** tracks memory usage, for example. </dd> 1430** 1431** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1432** <dd> ^This option takes single argument of type int, interpreted as a 1433** boolean, which enables or disables the collection of memory allocation 1434** statistics. ^(When memory allocation statistics are disabled, the 1435** following SQLite interfaces become non-operational: 1436** <ul> 1437** <li> [sqlite3_memory_used()] 1438** <li> [sqlite3_memory_highwater()] 1439** <li> [sqlite3_soft_heap_limit64()] 1440** <li> [sqlite3_status()] 1441** </ul>)^ 1442** ^Memory allocation statistics are enabled by default unless SQLite is 1443** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1444** allocation statistics are disabled by default. 1445** </dd> 1446** 1447** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1448** <dd> ^This option specifies a static memory buffer that SQLite can use for 1449** scratch memory. There are three arguments: A pointer an 8-byte 1450** aligned memory buffer from which the scratch allocations will be 1451** drawn, the size of each scratch allocation (sz), 1452** and the maximum number of scratch allocations (N). The sz 1453** argument must be a multiple of 16. 1454** The first argument must be a pointer to an 8-byte aligned buffer 1455** of at least sz*N bytes of memory. 1456** ^SQLite will use no more than two scratch buffers per thread. So 1457** N should be set to twice the expected maximum number of threads. 1458** ^SQLite will never require a scratch buffer that is more than 6 1459** times the database page size. ^If SQLite needs needs additional 1460** scratch memory beyond what is provided by this configuration option, then 1461** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1462** 1463** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1464** <dd> ^This option specifies a static memory buffer that SQLite can use for 1465** the database page cache with the default page cache implementation. 1466** This configuration should not be used if an application-define page 1467** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1468** There are three arguments to this option: A pointer to 8-byte aligned 1469** memory, the size of each page buffer (sz), and the number of pages (N). 1470** The sz argument should be the size of the largest database page 1471** (a power of two between 512 and 32768) plus a little extra for each 1472** page header. ^The page header size is 20 to 40 bytes depending on 1473** the host architecture. ^It is harmless, apart from the wasted memory, 1474** to make sz a little too large. The first 1475** argument should point to an allocation of at least sz*N bytes of memory. 1476** ^SQLite will use the memory provided by the first argument to satisfy its 1477** memory needs for the first N pages that it adds to cache. ^If additional 1478** page cache memory is needed beyond what is provided by this option, then 1479** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1480** The pointer in the first argument must 1481** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1482** will be undefined.</dd> 1483** 1484** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1485** <dd> ^This option specifies a static memory buffer that SQLite will use 1486** for all of its dynamic memory allocation needs beyond those provided 1487** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1488** There are three arguments: An 8-byte aligned pointer to the memory, 1489** the number of bytes in the memory buffer, and the minimum allocation size. 1490** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1491** to using its default memory allocator (the system malloc() implementation), 1492** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1493** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1494** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1495** allocator is engaged to handle all of SQLites memory allocation needs. 1496** The first pointer (the memory pointer) must be aligned to an 8-byte 1497** boundary or subsequent behavior of SQLite will be undefined. 1498** The minimum allocation size is capped at 2**12. Reasonable values 1499** for the minimum allocation size are 2**5 through 2**8.</dd> 1500** 1501** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1502** <dd> ^(This option takes a single argument which is a pointer to an 1503** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1504** alternative low-level mutex routines to be used in place 1505** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1506** content of the [sqlite3_mutex_methods] structure before the call to 1507** [sqlite3_config()] returns. ^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_MUTEX configuration option will 1511** return [SQLITE_ERROR].</dd> 1512** 1513** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1514** <dd> ^(This option takes a single argument which is a pointer to an 1515** instance of the [sqlite3_mutex_methods] structure. The 1516** [sqlite3_mutex_methods] 1517** structure is filled with the currently defined mutex routines.)^ 1518** This option can be used to overload the default mutex allocation 1519** routines with a wrapper used to track mutex usage for performance 1520** profiling or testing, for example. ^If SQLite is compiled with 1521** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1522** the entire mutexing subsystem is omitted from the build and hence calls to 1523** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1524** return [SQLITE_ERROR].</dd> 1525** 1526** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1527** <dd> ^(This option takes two arguments that determine the default 1528** memory allocation for the lookaside memory allocator on each 1529** [database connection]. The first argument is the 1530** size of each lookaside buffer slot and the second is the number of 1531** slots allocated to each database connection.)^ ^(This option sets the 1532** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1533** verb to [sqlite3_db_config()] can be used to change the lookaside 1534** configuration on individual connections.)^ </dd> 1535** 1536** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1537** <dd> ^(This option takes a single argument which is a pointer to 1538** an [sqlite3_pcache_methods2] object. This object specifies the interface 1539** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1540** object and uses it for page cache memory allocations.</dd> 1541** 1542** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1543** <dd> ^(This option takes a single argument which is a pointer to an 1544** [sqlite3_pcache_methods2] object. SQLite copies of the current 1545** page cache implementation into that object.)^ </dd> 1546** 1547** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1548** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1549** function with a call signature of void(*)(void*,int,const char*), 1550** and a pointer to void. ^If the function pointer is not NULL, it is 1551** invoked by [sqlite3_log()] to process each logging event. ^If the 1552** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1553** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1554** passed through as the first parameter to the application-defined logger 1555** function whenever that function is invoked. ^The second parameter to 1556** the logger function is a copy of the first parameter to the corresponding 1557** [sqlite3_log()] call and is intended to be a [result code] or an 1558** [extended result code]. ^The third parameter passed to the logger is 1559** log message after formatting via [sqlite3_snprintf()]. 1560** The SQLite logging interface is not reentrant; the logger function 1561** supplied by the application must not invoke any SQLite interface. 1562** In a multi-threaded application, the application-defined logger 1563** function must be threadsafe. </dd> 1564** 1565** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1566** <dd> This option takes a single argument of type int. If non-zero, then 1567** URI handling is globally enabled. If the parameter is zero, then URI handling 1568** is globally disabled. If URI handling is globally enabled, all filenames 1569** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1570** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1571** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1572** connection is opened. If it is globally disabled, filenames are 1573** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1574** database connection is opened. By default, URI handling is globally 1575** disabled. The default value may be changed by compiling with the 1576** [SQLITE_USE_URI] symbol defined. 1577** 1578** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1579** <dd> This option taks a single integer argument which is interpreted as 1580** a boolean in order to enable or disable the use of covering indices for 1581** full table scans in the query optimizer. The default setting is determined 1582** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1583** if that compile-time option is omitted. 1584** The ability to disable the use of covering indices for full table scans 1585** is because some incorrectly coded legacy applications might malfunction 1586** malfunction when the optimization is enabled. Providing the ability to 1587** disable the optimization allows the older, buggy application code to work 1588** without change even with newer versions of SQLite. 1589** 1590** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1591** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1592** <dd> These options are obsolete and should not be used by new code. 1593** They are retained for backwards compatibility but are now no-ops. 1594** </dl> 1595*/ 1596#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1597#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1598#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1599#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1600#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1601#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1602#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1603#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1604#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1605#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1606#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1607/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1608#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1609#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1610#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1611#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1612#define SQLITE_CONFIG_URI 17 /* int */ 1613#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1614#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1615#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1616 1617/* 1618** CAPI3REF: Database Connection Configuration Options 1619** 1620** These constants are the available integer configuration options that 1621** can be passed as the second argument to the [sqlite3_db_config()] interface. 1622** 1623** New configuration options may be added in future releases of SQLite. 1624** Existing configuration options might be discontinued. Applications 1625** should check the return code from [sqlite3_db_config()] to make sure that 1626** the call worked. ^The [sqlite3_db_config()] interface will return a 1627** non-zero [error code] if a discontinued or unsupported configuration option 1628** is invoked. 1629** 1630** <dl> 1631** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1632** <dd> ^This option takes three additional arguments that determine the 1633** [lookaside memory allocator] configuration for the [database connection]. 1634** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1635** pointer to a memory buffer to use for lookaside memory. 1636** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1637** may be NULL in which case SQLite will allocate the 1638** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1639** size of each lookaside buffer slot. ^The third argument is the number of 1640** slots. The size of the buffer in the first argument must be greater than 1641** or equal to the product of the second and third arguments. The buffer 1642** must be aligned to an 8-byte boundary. ^If the second argument to 1643** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1644** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1645** configuration for a database connection can only be changed when that 1646** connection is not currently using lookaside memory, or in other words 1647** when the "current value" returned by 1648** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1649** Any attempt to change the lookaside memory configuration when lookaside 1650** memory is in use leaves the configuration unchanged and returns 1651** [SQLITE_BUSY].)^</dd> 1652** 1653** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1654** <dd> ^This option is used to enable or disable the enforcement of 1655** [foreign key constraints]. There should be two additional arguments. 1656** The first argument is an integer which is 0 to disable FK enforcement, 1657** positive to enable FK enforcement or negative to leave FK enforcement 1658** unchanged. The second parameter is a pointer to an integer into which 1659** is written 0 or 1 to indicate whether FK enforcement is off or on 1660** following this call. The second parameter may be a NULL pointer, in 1661** which case the FK enforcement setting is not reported back. </dd> 1662** 1663** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1664** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1665** There should be two additional arguments. 1666** The first argument is an integer which is 0 to disable triggers, 1667** positive to enable triggers or negative to leave the setting unchanged. 1668** The second parameter is a pointer to an integer into which 1669** is written 0 or 1 to indicate whether triggers are disabled or enabled 1670** following this call. The second parameter may be a NULL pointer, in 1671** which case the trigger setting is not reported back. </dd> 1672** 1673** </dl> 1674*/ 1675#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1676#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1677#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1678 1679 1680/* 1681** CAPI3REF: Enable Or Disable Extended Result Codes 1682** 1683** ^The sqlite3_extended_result_codes() routine enables or disables the 1684** [extended result codes] feature of SQLite. ^The extended result 1685** codes are disabled by default for historical compatibility. 1686*/ 1687int sqlite3_extended_result_codes(sqlite3*, int onoff); 1688 1689/* 1690** CAPI3REF: Last Insert Rowid 1691** 1692** ^Each entry in an SQLite table has a unique 64-bit signed 1693** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1694** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1695** names are not also used by explicitly declared columns. ^If 1696** the table has a column of type [INTEGER PRIMARY KEY] then that column 1697** is another alias for the rowid. 1698** 1699** ^This routine returns the [rowid] of the most recent 1700** successful [INSERT] into the database from the [database connection] 1701** in the first argument. ^As of SQLite version 3.7.7, this routines 1702** records the last insert rowid of both ordinary tables and [virtual tables]. 1703** ^If no successful [INSERT]s 1704** have ever occurred on that database connection, zero is returned. 1705** 1706** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1707** method, then this routine will return the [rowid] of the inserted 1708** row as long as the trigger or virtual table method is running. 1709** But once the trigger or virtual table method ends, the value returned 1710** by this routine reverts to what it was before the trigger or virtual 1711** table method began.)^ 1712** 1713** ^An [INSERT] that fails due to a constraint violation is not a 1714** successful [INSERT] and does not change the value returned by this 1715** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1716** and INSERT OR ABORT make no changes to the return value of this 1717** routine when their insertion fails. ^(When INSERT OR REPLACE 1718** encounters a constraint violation, it does not fail. The 1719** INSERT continues to completion after deleting rows that caused 1720** the constraint problem so INSERT OR REPLACE will always change 1721** the return value of this interface.)^ 1722** 1723** ^For the purposes of this routine, an [INSERT] is considered to 1724** be successful even if it is subsequently rolled back. 1725** 1726** This function is accessible to SQL statements via the 1727** [last_insert_rowid() SQL function]. 1728** 1729** If a separate thread performs a new [INSERT] on the same 1730** database connection while the [sqlite3_last_insert_rowid()] 1731** function is running and thus changes the last insert [rowid], 1732** then the value returned by [sqlite3_last_insert_rowid()] is 1733** unpredictable and might not equal either the old or the new 1734** last insert [rowid]. 1735*/ 1736sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1737 1738/* 1739** CAPI3REF: Count The Number Of Rows Modified 1740** 1741** ^This function returns the number of database rows that were changed 1742** or inserted or deleted by the most recently completed SQL statement 1743** on the [database connection] specified by the first parameter. 1744** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1745** or [DELETE] statement are counted. Auxiliary changes caused by 1746** triggers or [foreign key actions] are not counted.)^ Use the 1747** [sqlite3_total_changes()] function to find the total number of changes 1748** including changes caused by triggers and foreign key actions. 1749** 1750** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1751** are not counted. Only real table changes are counted. 1752** 1753** ^(A "row change" is a change to a single row of a single table 1754** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1755** are changed as side effects of [REPLACE] constraint resolution, 1756** rollback, ABORT processing, [DROP TABLE], or by any other 1757** mechanisms do not count as direct row changes.)^ 1758** 1759** A "trigger context" is a scope of execution that begins and 1760** ends with the script of a [CREATE TRIGGER | trigger]. 1761** Most SQL statements are 1762** evaluated outside of any trigger. This is the "top level" 1763** trigger context. If a trigger fires from the top level, a 1764** new trigger context is entered for the duration of that one 1765** trigger. Subtriggers create subcontexts for their duration. 1766** 1767** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1768** not create a new trigger context. 1769** 1770** ^This function returns the number of direct row changes in the 1771** most recent INSERT, UPDATE, or DELETE statement within the same 1772** trigger context. 1773** 1774** ^Thus, when called from the top level, this function returns the 1775** number of changes in the most recent INSERT, UPDATE, or DELETE 1776** that also occurred at the top level. ^(Within the body of a trigger, 1777** the sqlite3_changes() interface can be called to find the number of 1778** changes in the most recently completed INSERT, UPDATE, or DELETE 1779** statement within the body of the same trigger. 1780** However, the number returned does not include changes 1781** caused by subtriggers since those have their own context.)^ 1782** 1783** See also the [sqlite3_total_changes()] interface, the 1784** [count_changes pragma], and the [changes() SQL function]. 1785** 1786** If a separate thread makes changes on the same database connection 1787** while [sqlite3_changes()] is running then the value returned 1788** is unpredictable and not meaningful. 1789*/ 1790int sqlite3_changes(sqlite3*); 1791 1792/* 1793** CAPI3REF: Total Number Of Rows Modified 1794** 1795** ^This function returns the number of row changes caused by [INSERT], 1796** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1797** ^(The count returned by sqlite3_total_changes() includes all changes 1798** from all [CREATE TRIGGER | trigger] contexts and changes made by 1799** [foreign key actions]. However, 1800** the count does not include changes used to implement [REPLACE] constraints, 1801** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1802** count does not include rows of views that fire an [INSTEAD OF trigger], 1803** though if the INSTEAD OF trigger makes changes of its own, those changes 1804** are counted.)^ 1805** ^The sqlite3_total_changes() function counts the changes as soon as 1806** the statement that makes them is completed (when the statement handle 1807** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1808** 1809** See also the [sqlite3_changes()] interface, the 1810** [count_changes pragma], and the [total_changes() SQL function]. 1811** 1812** If a separate thread makes changes on the same database connection 1813** while [sqlite3_total_changes()] is running then the value 1814** returned is unpredictable and not meaningful. 1815*/ 1816int sqlite3_total_changes(sqlite3*); 1817 1818/* 1819** CAPI3REF: Interrupt A Long-Running Query 1820** 1821** ^This function causes any pending database operation to abort and 1822** return at its earliest opportunity. This routine is typically 1823** called in response to a user action such as pressing "Cancel" 1824** or Ctrl-C where the user wants a long query operation to halt 1825** immediately. 1826** 1827** ^It is safe to call this routine from a thread different from the 1828** thread that is currently running the database operation. But it 1829** is not safe to call this routine with a [database connection] that 1830** is closed or might close before sqlite3_interrupt() returns. 1831** 1832** ^If an SQL operation is very nearly finished at the time when 1833** sqlite3_interrupt() is called, then it might not have an opportunity 1834** to be interrupted and might continue to completion. 1835** 1836** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1837** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1838** that is inside an explicit transaction, then the entire transaction 1839** will be rolled back automatically. 1840** 1841** ^The sqlite3_interrupt(D) call is in effect until all currently running 1842** SQL statements on [database connection] D complete. ^Any new SQL statements 1843** that are started after the sqlite3_interrupt() call and before the 1844** running statements reaches zero are interrupted as if they had been 1845** running prior to the sqlite3_interrupt() call. ^New SQL statements 1846** that are started after the running statement count reaches zero are 1847** not effected by the sqlite3_interrupt(). 1848** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1849** SQL statements is a no-op and has no effect on SQL statements 1850** that are started after the sqlite3_interrupt() call returns. 1851** 1852** If the database connection closes while [sqlite3_interrupt()] 1853** is running then bad things will likely happen. 1854*/ 1855void sqlite3_interrupt(sqlite3*); 1856 1857/* 1858** CAPI3REF: Determine If An SQL Statement Is Complete 1859** 1860** These routines are useful during command-line input to determine if the 1861** currently entered text seems to form a complete SQL statement or 1862** if additional input is needed before sending the text into 1863** SQLite for parsing. ^These routines return 1 if the input string 1864** appears to be a complete SQL statement. ^A statement is judged to be 1865** complete if it ends with a semicolon token and is not a prefix of a 1866** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1867** string literals or quoted identifier names or comments are not 1868** independent tokens (they are part of the token in which they are 1869** embedded) and thus do not count as a statement terminator. ^Whitespace 1870** and comments that follow the final semicolon are ignored. 1871** 1872** ^These routines return 0 if the statement is incomplete. ^If a 1873** memory allocation fails, then SQLITE_NOMEM is returned. 1874** 1875** ^These routines do not parse the SQL statements thus 1876** will not detect syntactically incorrect SQL. 1877** 1878** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 1879** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 1880** automatically by sqlite3_complete16(). If that initialization fails, 1881** then the return value from sqlite3_complete16() will be non-zero 1882** regardless of whether or not the input SQL is complete.)^ 1883** 1884** The input to [sqlite3_complete()] must be a zero-terminated 1885** UTF-8 string. 1886** 1887** The input to [sqlite3_complete16()] must be a zero-terminated 1888** UTF-16 string in native byte order. 1889*/ 1890int sqlite3_complete(const char *sql); 1891int sqlite3_complete16(const void *sql); 1892 1893/* 1894** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 1895** 1896** ^This routine sets a callback function that might be invoked whenever 1897** an attempt is made to open a database table that another thread 1898** or process has locked. 1899** 1900** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1901** is returned immediately upon encountering the lock. ^If the busy callback 1902** is not NULL, then the callback might be invoked with two arguments. 1903** 1904** ^The first argument to the busy handler is a copy of the void* pointer which 1905** is the third argument to sqlite3_busy_handler(). ^The second argument to 1906** the busy handler callback is the number of times that the busy handler has 1907** been invoked for this locking event. ^If the 1908** busy callback returns 0, then no additional attempts are made to 1909** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1910** ^If the callback returns non-zero, then another attempt 1911** is made to open the database for reading and the cycle repeats. 1912** 1913** The presence of a busy handler does not guarantee that it will be invoked 1914** when there is lock contention. ^If SQLite determines that invoking the busy 1915** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1916** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1917** Consider a scenario where one process is holding a read lock that 1918** it is trying to promote to a reserved lock and 1919** a second process is holding a reserved lock that it is trying 1920** to promote to an exclusive lock. The first process cannot proceed 1921** because it is blocked by the second and the second process cannot 1922** proceed because it is blocked by the first. If both processes 1923** invoke the busy handlers, neither will make any progress. Therefore, 1924** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1925** will induce the first process to release its read lock and allow 1926** the second process to proceed. 1927** 1928** ^The default busy callback is NULL. 1929** 1930** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1931** when SQLite is in the middle of a large transaction where all the 1932** changes will not fit into the in-memory cache. SQLite will 1933** already hold a RESERVED lock on the database file, but it needs 1934** to promote this lock to EXCLUSIVE so that it can spill cache 1935** pages into the database file without harm to concurrent 1936** readers. ^If it is unable to promote the lock, then the in-memory 1937** cache will be left in an inconsistent state and so the error 1938** code is promoted from the relatively benign [SQLITE_BUSY] to 1939** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 1940** forces an automatic rollback of the changes. See the 1941** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1942** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1943** this is important. 1944** 1945** ^(There can only be a single busy handler defined for each 1946** [database connection]. Setting a new busy handler clears any 1947** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 1948** will also set or clear the busy handler. 1949** 1950** The busy callback should not take any actions which modify the 1951** database connection that invoked the busy handler. Any such actions 1952** result in undefined behavior. 1953** 1954** A busy handler must not close the database connection 1955** or [prepared statement] that invoked the busy handler. 1956*/ 1957int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1958 1959/* 1960** CAPI3REF: Set A Busy Timeout 1961** 1962** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1963** for a specified amount of time when a table is locked. ^The handler 1964** will sleep multiple times until at least "ms" milliseconds of sleeping 1965** have accumulated. ^After at least "ms" milliseconds of sleeping, 1966** the handler returns 0 which causes [sqlite3_step()] to return 1967** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1968** 1969** ^Calling this routine with an argument less than or equal to zero 1970** turns off all busy handlers. 1971** 1972** ^(There can only be a single busy handler for a particular 1973** [database connection] any any given moment. If another busy handler 1974** was defined (using [sqlite3_busy_handler()]) prior to calling 1975** this routine, that other busy handler is cleared.)^ 1976*/ 1977int sqlite3_busy_timeout(sqlite3*, int ms); 1978 1979/* 1980** CAPI3REF: Convenience Routines For Running Queries 1981** 1982** This is a legacy interface that is preserved for backwards compatibility. 1983** Use of this interface is not recommended. 1984** 1985** Definition: A <b>result table</b> is memory data structure created by the 1986** [sqlite3_get_table()] interface. A result table records the 1987** complete query results from one or more queries. 1988** 1989** The table conceptually has a number of rows and columns. But 1990** these numbers are not part of the result table itself. These 1991** numbers are obtained separately. Let N be the number of rows 1992** and M be the number of columns. 1993** 1994** A result table is an array of pointers to zero-terminated UTF-8 strings. 1995** There are (N+1)*M elements in the array. The first M pointers point 1996** to zero-terminated strings that contain the names of the columns. 1997** The remaining entries all point to query results. NULL values result 1998** in NULL pointers. All other values are in their UTF-8 zero-terminated 1999** string representation as returned by [sqlite3_column_text()]. 2000** 2001** A result table might consist of one or more memory allocations. 2002** It is not safe to pass a result table directly to [sqlite3_free()]. 2003** A result table should be deallocated using [sqlite3_free_table()]. 2004** 2005** ^(As an example of the result table format, suppose a query result 2006** is as follows: 2007** 2008** <blockquote><pre> 2009** Name | Age 2010** ----------------------- 2011** Alice | 43 2012** Bob | 28 2013** Cindy | 21 2014** </pre></blockquote> 2015** 2016** There are two column (M==2) and three rows (N==3). Thus the 2017** result table has 8 entries. Suppose the result table is stored 2018** in an array names azResult. Then azResult holds this content: 2019** 2020** <blockquote><pre> 2021** azResult[0] = "Name"; 2022** azResult[1] = "Age"; 2023** azResult[2] = "Alice"; 2024** azResult[3] = "43"; 2025** azResult[4] = "Bob"; 2026** azResult[5] = "28"; 2027** azResult[6] = "Cindy"; 2028** azResult[7] = "21"; 2029** </pre></blockquote>)^ 2030** 2031** ^The sqlite3_get_table() function evaluates one or more 2032** semicolon-separated SQL statements in the zero-terminated UTF-8 2033** string of its 2nd parameter and returns a result table to the 2034** pointer given in its 3rd parameter. 2035** 2036** After the application has finished with the result from sqlite3_get_table(), 2037** it must pass the result table pointer to sqlite3_free_table() in order to 2038** release the memory that was malloced. Because of the way the 2039** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2040** function must not try to call [sqlite3_free()] directly. Only 2041** [sqlite3_free_table()] is able to release the memory properly and safely. 2042** 2043** The sqlite3_get_table() interface is implemented as a wrapper around 2044** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2045** to any internal data structures of SQLite. It uses only the public 2046** interface defined here. As a consequence, errors that occur in the 2047** wrapper layer outside of the internal [sqlite3_exec()] call are not 2048** reflected in subsequent calls to [sqlite3_errcode()] or 2049** [sqlite3_errmsg()]. 2050*/ 2051int sqlite3_get_table( 2052 sqlite3 *db, /* An open database */ 2053 const char *zSql, /* SQL to be evaluated */ 2054 char ***pazResult, /* Results of the query */ 2055 int *pnRow, /* Number of result rows written here */ 2056 int *pnColumn, /* Number of result columns written here */ 2057 char **pzErrmsg /* Error msg written here */ 2058); 2059void sqlite3_free_table(char **result); 2060 2061/* 2062** CAPI3REF: Formatted String Printing Functions 2063** 2064** These routines are work-alikes of the "printf()" family of functions 2065** from the standard C library. 2066** 2067** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2068** results into memory obtained from [sqlite3_malloc()]. 2069** The strings returned by these two routines should be 2070** released by [sqlite3_free()]. ^Both routines return a 2071** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2072** memory to hold the resulting string. 2073** 2074** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2075** the standard C library. The result is written into the 2076** buffer supplied as the second parameter whose size is given by 2077** the first parameter. Note that the order of the 2078** first two parameters is reversed from snprintf().)^ This is an 2079** historical accident that cannot be fixed without breaking 2080** backwards compatibility. ^(Note also that sqlite3_snprintf() 2081** returns a pointer to its buffer instead of the number of 2082** characters actually written into the buffer.)^ We admit that 2083** the number of characters written would be a more useful return 2084** value but we cannot change the implementation of sqlite3_snprintf() 2085** now without breaking compatibility. 2086** 2087** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2088** guarantees that the buffer is always zero-terminated. ^The first 2089** parameter "n" is the total size of the buffer, including space for 2090** the zero terminator. So the longest string that can be completely 2091** written will be n-1 characters. 2092** 2093** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2094** 2095** These routines all implement some additional formatting 2096** options that are useful for constructing SQL statements. 2097** All of the usual printf() formatting options apply. In addition, there 2098** is are "%q", "%Q", and "%z" options. 2099** 2100** ^(The %q option works like %s in that it substitutes a nul-terminated 2101** string from the argument list. But %q also doubles every '\'' character. 2102** %q is designed for use inside a string literal.)^ By doubling each '\'' 2103** character it escapes that character and allows it to be inserted into 2104** the string. 2105** 2106** For example, assume the string variable zText contains text as follows: 2107** 2108** <blockquote><pre> 2109** char *zText = "It's a happy day!"; 2110** </pre></blockquote> 2111** 2112** One can use this text in an SQL statement as follows: 2113** 2114** <blockquote><pre> 2115** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2116** sqlite3_exec(db, zSQL, 0, 0, 0); 2117** sqlite3_free(zSQL); 2118** </pre></blockquote> 2119** 2120** Because the %q format string is used, the '\'' character in zText 2121** is escaped and the SQL generated is as follows: 2122** 2123** <blockquote><pre> 2124** INSERT INTO table1 VALUES('It''s a happy day!') 2125** </pre></blockquote> 2126** 2127** This is correct. Had we used %s instead of %q, the generated SQL 2128** would have looked like this: 2129** 2130** <blockquote><pre> 2131** INSERT INTO table1 VALUES('It's a happy day!'); 2132** </pre></blockquote> 2133** 2134** This second example is an SQL syntax error. As a general rule you should 2135** always use %q instead of %s when inserting text into a string literal. 2136** 2137** ^(The %Q option works like %q except it also adds single quotes around 2138** the outside of the total string. Additionally, if the parameter in the 2139** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2140** single quotes).)^ So, for example, one could say: 2141** 2142** <blockquote><pre> 2143** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2144** sqlite3_exec(db, zSQL, 0, 0, 0); 2145** sqlite3_free(zSQL); 2146** </pre></blockquote> 2147** 2148** The code above will render a correct SQL statement in the zSQL 2149** variable even if the zText variable is a NULL pointer. 2150** 2151** ^(The "%z" formatting option works like "%s" but with the 2152** addition that after the string has been read and copied into 2153** the result, [sqlite3_free()] is called on the input string.)^ 2154*/ 2155char *sqlite3_mprintf(const char*,...); 2156char *sqlite3_vmprintf(const char*, va_list); 2157char *sqlite3_snprintf(int,char*,const char*, ...); 2158char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2159 2160/* 2161** CAPI3REF: Memory Allocation Subsystem 2162** 2163** The SQLite core uses these three routines for all of its own 2164** internal memory allocation needs. "Core" in the previous sentence 2165** does not include operating-system specific VFS implementation. The 2166** Windows VFS uses native malloc() and free() for some operations. 2167** 2168** ^The sqlite3_malloc() routine returns a pointer to a block 2169** of memory at least N bytes in length, where N is the parameter. 2170** ^If sqlite3_malloc() is unable to obtain sufficient free 2171** memory, it returns a NULL pointer. ^If the parameter N to 2172** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2173** a NULL pointer. 2174** 2175** ^Calling sqlite3_free() with a pointer previously returned 2176** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2177** that it might be reused. ^The sqlite3_free() routine is 2178** a no-op if is called with a NULL pointer. Passing a NULL pointer 2179** to sqlite3_free() is harmless. After being freed, memory 2180** should neither be read nor written. Even reading previously freed 2181** memory might result in a segmentation fault or other severe error. 2182** Memory corruption, a segmentation fault, or other severe error 2183** might result if sqlite3_free() is called with a non-NULL pointer that 2184** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2185** 2186** ^(The sqlite3_realloc() interface attempts to resize a 2187** prior memory allocation to be at least N bytes, where N is the 2188** second parameter. The memory allocation to be resized is the first 2189** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2190** is a NULL pointer then its behavior is identical to calling 2191** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2192** ^If the second parameter to sqlite3_realloc() is zero or 2193** negative then the behavior is exactly the same as calling 2194** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2195** ^sqlite3_realloc() returns a pointer to a memory allocation 2196** of at least N bytes in size or NULL if sufficient memory is unavailable. 2197** ^If M is the size of the prior allocation, then min(N,M) bytes 2198** of the prior allocation are copied into the beginning of buffer returned 2199** by sqlite3_realloc() and the prior allocation is freed. 2200** ^If sqlite3_realloc() returns NULL, then the prior allocation 2201** is not freed. 2202** 2203** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2204** is always aligned to at least an 8 byte boundary, or to a 2205** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2206** option is used. 2207** 2208** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2209** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2210** implementation of these routines to be omitted. That capability 2211** is no longer provided. Only built-in memory allocators can be used. 2212** 2213** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2214** the system malloc() and free() directly when converting 2215** filenames between the UTF-8 encoding used by SQLite 2216** and whatever filename encoding is used by the particular Windows 2217** installation. Memory allocation errors were detected, but 2218** they were reported back as [SQLITE_CANTOPEN] or 2219** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2220** 2221** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2222** must be either NULL or else pointers obtained from a prior 2223** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2224** not yet been released. 2225** 2226** The application must not read or write any part of 2227** a block of memory after it has been released using 2228** [sqlite3_free()] or [sqlite3_realloc()]. 2229*/ 2230void *sqlite3_malloc(int); 2231void *sqlite3_realloc(void*, int); 2232void sqlite3_free(void*); 2233 2234/* 2235** CAPI3REF: Memory Allocator Statistics 2236** 2237** SQLite provides these two interfaces for reporting on the status 2238** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2239** routines, which form the built-in memory allocation subsystem. 2240** 2241** ^The [sqlite3_memory_used()] routine returns the number of bytes 2242** of memory currently outstanding (malloced but not freed). 2243** ^The [sqlite3_memory_highwater()] routine returns the maximum 2244** value of [sqlite3_memory_used()] since the high-water mark 2245** was last reset. ^The values returned by [sqlite3_memory_used()] and 2246** [sqlite3_memory_highwater()] include any overhead 2247** added by SQLite in its implementation of [sqlite3_malloc()], 2248** but not overhead added by the any underlying system library 2249** routines that [sqlite3_malloc()] may call. 2250** 2251** ^The memory high-water mark is reset to the current value of 2252** [sqlite3_memory_used()] if and only if the parameter to 2253** [sqlite3_memory_highwater()] is true. ^The value returned 2254** by [sqlite3_memory_highwater(1)] is the high-water mark 2255** prior to the reset. 2256*/ 2257sqlite3_int64 sqlite3_memory_used(void); 2258sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2259 2260/* 2261** CAPI3REF: Pseudo-Random Number Generator 2262** 2263** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2264** select random [ROWID | ROWIDs] when inserting new records into a table that 2265** already uses the largest possible [ROWID]. The PRNG is also used for 2266** the build-in random() and randomblob() SQL functions. This interface allows 2267** applications to access the same PRNG for other purposes. 2268** 2269** ^A call to this routine stores N bytes of randomness into buffer P. 2270** 2271** ^The first time this routine is invoked (either internally or by 2272** the application) the PRNG is seeded using randomness obtained 2273** from the xRandomness method of the default [sqlite3_vfs] object. 2274** ^On all subsequent invocations, the pseudo-randomness is generated 2275** internally and without recourse to the [sqlite3_vfs] xRandomness 2276** method. 2277*/ 2278void sqlite3_randomness(int N, void *P); 2279 2280/* 2281** CAPI3REF: Compile-Time Authorization Callbacks 2282** 2283** ^This routine registers an authorizer callback with a particular 2284** [database connection], supplied in the first argument. 2285** ^The authorizer callback is invoked as SQL statements are being compiled 2286** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2287** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2288** points during the compilation process, as logic is being created 2289** to perform various actions, the authorizer callback is invoked to 2290** see if those actions are allowed. ^The authorizer callback should 2291** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2292** specific action but allow the SQL statement to continue to be 2293** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2294** rejected with an error. ^If the authorizer callback returns 2295** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2296** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2297** the authorizer will fail with an error message. 2298** 2299** When the callback returns [SQLITE_OK], that means the operation 2300** requested is ok. ^When the callback returns [SQLITE_DENY], the 2301** [sqlite3_prepare_v2()] or equivalent call that triggered the 2302** authorizer will fail with an error message explaining that 2303** access is denied. 2304** 2305** ^The first parameter to the authorizer callback is a copy of the third 2306** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2307** to the callback is an integer [SQLITE_COPY | action code] that specifies 2308** the particular action to be authorized. ^The third through sixth parameters 2309** to the callback are zero-terminated strings that contain additional 2310** details about the action to be authorized. 2311** 2312** ^If the action code is [SQLITE_READ] 2313** and the callback returns [SQLITE_IGNORE] then the 2314** [prepared statement] statement is constructed to substitute 2315** a NULL value in place of the table column that would have 2316** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2317** return can be used to deny an untrusted user access to individual 2318** columns of a table. 2319** ^If the action code is [SQLITE_DELETE] and the callback returns 2320** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2321** [truncate optimization] is disabled and all rows are deleted individually. 2322** 2323** An authorizer is used when [sqlite3_prepare | preparing] 2324** SQL statements from an untrusted source, to ensure that the SQL statements 2325** do not try to access data they are not allowed to see, or that they do not 2326** try to execute malicious statements that damage the database. For 2327** example, an application may allow a user to enter arbitrary 2328** SQL queries for evaluation by a database. But the application does 2329** not want the user to be able to make arbitrary changes to the 2330** database. An authorizer could then be put in place while the 2331** user-entered SQL is being [sqlite3_prepare | prepared] that 2332** disallows everything except [SELECT] statements. 2333** 2334** Applications that need to process SQL from untrusted sources 2335** might also consider lowering resource limits using [sqlite3_limit()] 2336** and limiting database size using the [max_page_count] [PRAGMA] 2337** in addition to using an authorizer. 2338** 2339** ^(Only a single authorizer can be in place on a database connection 2340** at a time. Each call to sqlite3_set_authorizer overrides the 2341** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2342** The authorizer is disabled by default. 2343** 2344** The authorizer callback must not do anything that will modify 2345** the database connection that invoked the authorizer callback. 2346** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2347** database connections for the meaning of "modify" in this paragraph. 2348** 2349** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2350** statement might be re-prepared during [sqlite3_step()] due to a 2351** schema change. Hence, the application should ensure that the 2352** correct authorizer callback remains in place during the [sqlite3_step()]. 2353** 2354** ^Note that the authorizer callback is invoked only during 2355** [sqlite3_prepare()] or its variants. Authorization is not 2356** performed during statement evaluation in [sqlite3_step()], unless 2357** as stated in the previous paragraph, sqlite3_step() invokes 2358** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2359*/ 2360int sqlite3_set_authorizer( 2361 sqlite3*, 2362 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2363 void *pUserData 2364); 2365 2366/* 2367** CAPI3REF: Authorizer Return Codes 2368** 2369** The [sqlite3_set_authorizer | authorizer callback function] must 2370** return either [SQLITE_OK] or one of these two constants in order 2371** to signal SQLite whether or not the action is permitted. See the 2372** [sqlite3_set_authorizer | authorizer documentation] for additional 2373** information. 2374** 2375** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] 2376** from the [sqlite3_vtab_on_conflict()] interface. 2377*/ 2378#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2379#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2380 2381/* 2382** CAPI3REF: Authorizer Action Codes 2383** 2384** The [sqlite3_set_authorizer()] interface registers a callback function 2385** that is invoked to authorize certain SQL statement actions. The 2386** second parameter to the callback is an integer code that specifies 2387** what action is being authorized. These are the integer action codes that 2388** the authorizer callback may be passed. 2389** 2390** These action code values signify what kind of operation is to be 2391** authorized. The 3rd and 4th parameters to the authorization 2392** callback function will be parameters or NULL depending on which of these 2393** codes is used as the second parameter. ^(The 5th parameter to the 2394** authorizer callback is the name of the database ("main", "temp", 2395** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2396** is the name of the inner-most trigger or view that is responsible for 2397** the access attempt or NULL if this access attempt is directly from 2398** top-level SQL code. 2399*/ 2400/******************************************* 3rd ************ 4th ***********/ 2401#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2402#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2403#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2404#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2405#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2406#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2407#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2408#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2409#define SQLITE_DELETE 9 /* Table Name NULL */ 2410#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2411#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2412#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2413#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2414#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2415#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2416#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2417#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2418#define SQLITE_INSERT 18 /* Table Name NULL */ 2419#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2420#define SQLITE_READ 20 /* Table Name Column Name */ 2421#define SQLITE_SELECT 21 /* NULL NULL */ 2422#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2423#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2424#define SQLITE_ATTACH 24 /* Filename NULL */ 2425#define SQLITE_DETACH 25 /* Database Name NULL */ 2426#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2427#define SQLITE_REINDEX 27 /* Index Name NULL */ 2428#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2429#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2430#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2431#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2432#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2433#define SQLITE_COPY 0 /* No longer used */ 2434 2435/* 2436** CAPI3REF: Tracing And Profiling Functions 2437** 2438** These routines register callback functions that can be used for 2439** tracing and profiling the execution of SQL statements. 2440** 2441** ^The callback function registered by sqlite3_trace() is invoked at 2442** various times when an SQL statement is being run by [sqlite3_step()]. 2443** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2444** SQL statement text as the statement first begins executing. 2445** ^(Additional sqlite3_trace() callbacks might occur 2446** as each triggered subprogram is entered. The callbacks for triggers 2447** contain a UTF-8 SQL comment that identifies the trigger.)^ 2448** 2449** ^The callback function registered by sqlite3_profile() is invoked 2450** as each SQL statement finishes. ^The profile callback contains 2451** the original statement text and an estimate of wall-clock time 2452** of how long that statement took to run. ^The profile callback 2453** time is in units of nanoseconds, however the current implementation 2454** is only capable of millisecond resolution so the six least significant 2455** digits in the time are meaningless. Future versions of SQLite 2456** might provide greater resolution on the profiler callback. The 2457** sqlite3_profile() function is considered experimental and is 2458** subject to change in future versions of SQLite. 2459*/ 2460void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2461SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2462 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2463 2464/* 2465** CAPI3REF: Query Progress Callbacks 2466** 2467** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2468** function X to be invoked periodically during long running calls to 2469** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2470** database connection D. An example use for this 2471** interface is to keep a GUI updated during a large query. 2472** 2473** ^The parameter P is passed through as the only parameter to the 2474** callback function X. ^The parameter N is the number of 2475** [virtual machine instructions] that are evaluated between successive 2476** invocations of the callback X. 2477** 2478** ^Only a single progress handler may be defined at one time per 2479** [database connection]; setting a new progress handler cancels the 2480** old one. ^Setting parameter X to NULL disables the progress handler. 2481** ^The progress handler is also disabled by setting N to a value less 2482** than 1. 2483** 2484** ^If the progress callback returns non-zero, the operation is 2485** interrupted. This feature can be used to implement a 2486** "Cancel" button on a GUI progress dialog box. 2487** 2488** The progress handler callback must not do anything that will modify 2489** the database connection that invoked the progress handler. 2490** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2491** database connections for the meaning of "modify" in this paragraph. 2492** 2493*/ 2494void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2495 2496/* 2497** CAPI3REF: Opening A New Database Connection 2498** 2499** ^These routines open an SQLite database file as specified by the 2500** filename argument. ^The filename argument is interpreted as UTF-8 for 2501** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2502** order for sqlite3_open16(). ^(A [database connection] handle is usually 2503** returned in *ppDb, even if an error occurs. The only exception is that 2504** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2505** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2506** object.)^ ^(If the database is opened (and/or created) successfully, then 2507** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2508** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2509** an English language description of the error following a failure of any 2510** of the sqlite3_open() routines. 2511** 2512** ^The default encoding for the database will be UTF-8 if 2513** sqlite3_open() or sqlite3_open_v2() is called and 2514** UTF-16 in the native byte order if sqlite3_open16() is used. 2515** 2516** Whether or not an error occurs when it is opened, resources 2517** associated with the [database connection] handle should be released by 2518** passing it to [sqlite3_close()] when it is no longer required. 2519** 2520** The sqlite3_open_v2() interface works like sqlite3_open() 2521** except that it accepts two additional parameters for additional control 2522** over the new database connection. ^(The flags parameter to 2523** sqlite3_open_v2() can take one of 2524** the following three values, optionally combined with the 2525** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2526** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2527** 2528** <dl> 2529** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2530** <dd>The database is opened in read-only mode. If the database does not 2531** already exist, an error is returned.</dd>)^ 2532** 2533** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2534** <dd>The database is opened for reading and writing if possible, or reading 2535** only if the file is write protected by the operating system. In either 2536** case the database must already exist, otherwise an error is returned.</dd>)^ 2537** 2538** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2539** <dd>The database is opened for reading and writing, and is created if 2540** it does not already exist. This is the behavior that is always used for 2541** sqlite3_open() and sqlite3_open16().</dd>)^ 2542** </dl> 2543** 2544** If the 3rd parameter to sqlite3_open_v2() is not one of the 2545** combinations shown above optionally combined with other 2546** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2547** then the behavior is undefined. 2548** 2549** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2550** opens in the multi-thread [threading mode] as long as the single-thread 2551** mode has not been set at compile-time or start-time. ^If the 2552** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2553** in the serialized [threading mode] unless single-thread was 2554** previously selected at compile-time or start-time. 2555** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2556** eligible to use [shared cache mode], regardless of whether or not shared 2557** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2558** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2559** participate in [shared cache mode] even if it is enabled. 2560** 2561** ^The fourth parameter to sqlite3_open_v2() is the name of the 2562** [sqlite3_vfs] object that defines the operating system interface that 2563** the new database connection should use. ^If the fourth parameter is 2564** a NULL pointer then the default [sqlite3_vfs] object is used. 2565** 2566** ^If the filename is ":memory:", then a private, temporary in-memory database 2567** is created for the connection. ^This in-memory database will vanish when 2568** the database connection is closed. Future versions of SQLite might 2569** make use of additional special filenames that begin with the ":" character. 2570** It is recommended that when a database filename actually does begin with 2571** a ":" character you should prefix the filename with a pathname such as 2572** "./" to avoid ambiguity. 2573** 2574** ^If the filename is an empty string, then a private, temporary 2575** on-disk database will be created. ^This private database will be 2576** automatically deleted as soon as the database connection is closed. 2577** 2578** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2579** 2580** ^If [URI filename] interpretation is enabled, and the filename argument 2581** begins with "file:", then the filename is interpreted as a URI. ^URI 2582** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2583** set in the fourth argument to sqlite3_open_v2(), or if it has 2584** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2585** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2586** As of SQLite version 3.7.7, URI filename interpretation is turned off 2587** by default, but future releases of SQLite might enable URI filename 2588** interpretation by default. See "[URI filenames]" for additional 2589** information. 2590** 2591** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2592** authority, then it must be either an empty string or the string 2593** "localhost". ^If the authority is not an empty string or "localhost", an 2594** error is returned to the caller. ^The fragment component of a URI, if 2595** present, is ignored. 2596** 2597** ^SQLite uses the path component of the URI as the name of the disk file 2598** which contains the database. ^If the path begins with a '/' character, 2599** then it is interpreted as an absolute path. ^If the path does not begin 2600** with a '/' (meaning that the authority section is omitted from the URI) 2601** then the path is interpreted as a relative path. 2602** ^On windows, the first component of an absolute path 2603** is a drive specification (e.g. "C:"). 2604** 2605** [[core URI query parameters]] 2606** The query component of a URI may contain parameters that are interpreted 2607** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2608** SQLite interprets the following three query parameters: 2609** 2610** <ul> 2611** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2612** a VFS object that provides the operating system interface that should 2613** be used to access the database file on disk. ^If this option is set to 2614** an empty string the default VFS object is used. ^Specifying an unknown 2615** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2616** present, then the VFS specified by the option takes precedence over 2617** the value passed as the fourth parameter to sqlite3_open_v2(). 2618** 2619** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2620** "rwc", or "memory". Attempting to set it to any other value is 2621** an error)^. 2622** ^If "ro" is specified, then the database is opened for read-only 2623** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2624** third argument to sqlite3_open_v2(). ^If the mode option is set to 2625** "rw", then the database is opened for read-write (but not create) 2626** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2627** been set. ^Value "rwc" is equivalent to setting both 2628** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2629** set to "memory" then a pure [in-memory database] that never reads 2630** or writes from disk is used. ^It is an error to specify a value for 2631** the mode parameter that is less restrictive than that specified by 2632** the flags passed in the third parameter to sqlite3_open_v2(). 2633** 2634** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2635** "private". ^Setting it to "shared" is equivalent to setting the 2636** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2637** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2638** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2639** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2640** a URI filename, its value overrides any behaviour requested by setting 2641** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2642** </ul> 2643** 2644** ^Specifying an unknown parameter in the query component of a URI is not an 2645** error. Future versions of SQLite might understand additional query 2646** parameters. See "[query parameters with special meaning to SQLite]" for 2647** additional information. 2648** 2649** [[URI filename examples]] <h3>URI filename examples</h3> 2650** 2651** <table border="1" align=center cellpadding=5> 2652** <tr><th> URI filenames <th> Results 2653** <tr><td> file:data.db <td> 2654** Open the file "data.db" in the current directory. 2655** <tr><td> file:/home/fred/data.db<br> 2656** file:///home/fred/data.db <br> 2657** file://localhost/home/fred/data.db <br> <td> 2658** Open the database file "/home/fred/data.db". 2659** <tr><td> file://darkstar/home/fred/data.db <td> 2660** An error. "darkstar" is not a recognized authority. 2661** <tr><td style="white-space:nowrap"> 2662** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2663** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2664** C:. Note that the %20 escaping in this example is not strictly 2665** necessary - space characters can be used literally 2666** in URI filenames. 2667** <tr><td> file:data.db?mode=ro&cache=private <td> 2668** Open file "data.db" in the current directory for read-only access. 2669** Regardless of whether or not shared-cache mode is enabled by 2670** default, use a private cache. 2671** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> 2672** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". 2673** <tr><td> file:data.db?mode=readonly <td> 2674** An error. "readonly" is not a valid option for the "mode" parameter. 2675** </table> 2676** 2677** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2678** query components of a URI. A hexadecimal escape sequence consists of a 2679** percent sign - "%" - followed by exactly two hexadecimal digits 2680** specifying an octet value. ^Before the path or query components of a 2681** URI filename are interpreted, they are encoded using UTF-8 and all 2682** hexadecimal escape sequences replaced by a single byte containing the 2683** corresponding octet. If this process generates an invalid UTF-8 encoding, 2684** the results are undefined. 2685** 2686** <b>Note to Windows users:</b> The encoding used for the filename argument 2687** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2688** codepage is currently defined. Filenames containing international 2689** characters must be converted to UTF-8 prior to passing them into 2690** sqlite3_open() or sqlite3_open_v2(). 2691** 2692** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2693** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2694** features that require the use of temporary files may fail. 2695** 2696** See also: [sqlite3_temp_directory] 2697*/ 2698int sqlite3_open( 2699 const char *filename, /* Database filename (UTF-8) */ 2700 sqlite3 **ppDb /* OUT: SQLite db handle */ 2701); 2702int sqlite3_open16( 2703 const void *filename, /* Database filename (UTF-16) */ 2704 sqlite3 **ppDb /* OUT: SQLite db handle */ 2705); 2706int sqlite3_open_v2( 2707 const char *filename, /* Database filename (UTF-8) */ 2708 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2709 int flags, /* Flags */ 2710 const char *zVfs /* Name of VFS module to use */ 2711); 2712 2713/* 2714** CAPI3REF: Obtain Values For URI Parameters 2715** 2716** These are utility routines, useful to VFS implementations, that check 2717** to see if a database file was a URI that contained a specific query 2718** parameter, and if so obtains the value of that query parameter. 2719** 2720** If F is the database filename pointer passed into the xOpen() method of 2721** a VFS implementation when the flags parameter to xOpen() has one or 2722** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2723** P is the name of the query parameter, then 2724** sqlite3_uri_parameter(F,P) returns the value of the P 2725** parameter if it exists or a NULL pointer if P does not appear as a 2726** query parameter on F. If P is a query parameter of F 2727** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2728** a pointer to an empty string. 2729** 2730** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2731** parameter and returns true (1) or false (0) according to the value 2732** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 2733** value of query parameter P is one of "yes", "true", or "on" in any 2734** case or if the value begins with a non-zero number. The 2735** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 2736** query parameter P is one of "no", "false", or "off" in any case or 2737** if the value begins with a numeric zero. If P is not a query 2738** parameter on F or if the value of P is does not match any of the 2739** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2740** 2741** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2742** 64-bit signed integer and returns that integer, or D if P does not 2743** exist. If the value of P is something other than an integer, then 2744** zero is returned. 2745** 2746** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2747** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2748** is not a database file pathname pointer that SQLite passed into the xOpen 2749** VFS method, then the behavior of this routine is undefined and probably 2750** undesirable. 2751*/ 2752const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2753int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 2754sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 2755 2756 2757/* 2758** CAPI3REF: Error Codes And Messages 2759** 2760** ^The sqlite3_errcode() interface returns the numeric [result code] or 2761** [extended result code] for the most recent failed sqlite3_* API call 2762** associated with a [database connection]. If a prior API call failed 2763** but the most recent API call succeeded, the return value from 2764** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2765** interface is the same except that it always returns the 2766** [extended result code] even when extended result codes are 2767** disabled. 2768** 2769** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2770** text that describes the error, as either UTF-8 or UTF-16 respectively. 2771** ^(Memory to hold the error message string is managed internally. 2772** The application does not need to worry about freeing the result. 2773** However, the error string might be overwritten or deallocated by 2774** subsequent calls to other SQLite interface functions.)^ 2775** 2776** ^The sqlite3_errstr() interface returns the English-language text 2777** that describes the [result code], as UTF-8. 2778** ^(Memory to hold the error message string is managed internally 2779** and must not be freed by the application)^. 2780** 2781** When the serialized [threading mode] is in use, it might be the 2782** case that a second error occurs on a separate thread in between 2783** the time of the first error and the call to these interfaces. 2784** When that happens, the second error will be reported since these 2785** interfaces always report the most recent result. To avoid 2786** this, each thread can obtain exclusive use of the [database connection] D 2787** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2788** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2789** all calls to the interfaces listed here are completed. 2790** 2791** If an interface fails with SQLITE_MISUSE, that means the interface 2792** was invoked incorrectly by the application. In that case, the 2793** error code and message may or may not be set. 2794*/ 2795int sqlite3_errcode(sqlite3 *db); 2796int sqlite3_extended_errcode(sqlite3 *db); 2797const char *sqlite3_errmsg(sqlite3*); 2798const void *sqlite3_errmsg16(sqlite3*); 2799const char *sqlite3_errstr(int); 2800 2801/* 2802** CAPI3REF: SQL Statement Object 2803** KEYWORDS: {prepared statement} {prepared statements} 2804** 2805** An instance of this object represents a single SQL statement. 2806** This object is variously known as a "prepared statement" or a 2807** "compiled SQL statement" or simply as a "statement". 2808** 2809** The life of a statement object goes something like this: 2810** 2811** <ol> 2812** <li> Create the object using [sqlite3_prepare_v2()] or a related 2813** function. 2814** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2815** interfaces. 2816** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2817** <li> Reset the statement using [sqlite3_reset()] then go back 2818** to step 2. Do this zero or more times. 2819** <li> Destroy the object using [sqlite3_finalize()]. 2820** </ol> 2821** 2822** Refer to documentation on individual methods above for additional 2823** information. 2824*/ 2825typedef struct sqlite3_stmt sqlite3_stmt; 2826 2827/* 2828** CAPI3REF: Run-time Limits 2829** 2830** ^(This interface allows the size of various constructs to be limited 2831** on a connection by connection basis. The first parameter is the 2832** [database connection] whose limit is to be set or queried. The 2833** second parameter is one of the [limit categories] that define a 2834** class of constructs to be size limited. The third parameter is the 2835** new limit for that construct.)^ 2836** 2837** ^If the new limit is a negative number, the limit is unchanged. 2838** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2839** [limits | hard upper bound] 2840** set at compile-time by a C preprocessor macro called 2841** [limits | SQLITE_MAX_<i>NAME</i>]. 2842** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2843** ^Attempts to increase a limit above its hard upper bound are 2844** silently truncated to the hard upper bound. 2845** 2846** ^Regardless of whether or not the limit was changed, the 2847** [sqlite3_limit()] interface returns the prior value of the limit. 2848** ^Hence, to find the current value of a limit without changing it, 2849** simply invoke this interface with the third parameter set to -1. 2850** 2851** Run-time limits are intended for use in applications that manage 2852** both their own internal database and also databases that are controlled 2853** by untrusted external sources. An example application might be a 2854** web browser that has its own databases for storing history and 2855** separate databases controlled by JavaScript applications downloaded 2856** off the Internet. The internal databases can be given the 2857** large, default limits. Databases managed by external sources can 2858** be given much smaller limits designed to prevent a denial of service 2859** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2860** interface to further control untrusted SQL. The size of the database 2861** created by an untrusted script can be contained using the 2862** [max_page_count] [PRAGMA]. 2863** 2864** New run-time limit categories may be added in future releases. 2865*/ 2866int sqlite3_limit(sqlite3*, int id, int newVal); 2867 2868/* 2869** CAPI3REF: Run-Time Limit Categories 2870** KEYWORDS: {limit category} {*limit categories} 2871** 2872** These constants define various performance limits 2873** that can be lowered at run-time using [sqlite3_limit()]. 2874** The synopsis of the meanings of the various limits is shown below. 2875** Additional information is available at [limits | Limits in SQLite]. 2876** 2877** <dl> 2878** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 2879** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 2880** 2881** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2882** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 2883** 2884** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 2885** <dd>The maximum number of columns in a table definition or in the 2886** result set of a [SELECT] or the maximum number of columns in an index 2887** or in an ORDER BY or GROUP BY clause.</dd>)^ 2888** 2889** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2890** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 2891** 2892** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2893** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 2894** 2895** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 2896** <dd>The maximum number of instructions in a virtual machine program 2897** used to implement an SQL statement. This limit is not currently 2898** enforced, though that might be added in some future release of 2899** SQLite.</dd>)^ 2900** 2901** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2902** <dd>The maximum number of arguments on a function.</dd>)^ 2903** 2904** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 2905** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 2906** 2907** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 2908** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2909** <dd>The maximum length of the pattern argument to the [LIKE] or 2910** [GLOB] operators.</dd>)^ 2911** 2912** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 2913** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2914** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 2915** 2916** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 2917** <dd>The maximum depth of recursion for triggers.</dd>)^ 2918** </dl> 2919*/ 2920#define SQLITE_LIMIT_LENGTH 0 2921#define SQLITE_LIMIT_SQL_LENGTH 1 2922#define SQLITE_LIMIT_COLUMN 2 2923#define SQLITE_LIMIT_EXPR_DEPTH 3 2924#define SQLITE_LIMIT_COMPOUND_SELECT 4 2925#define SQLITE_LIMIT_VDBE_OP 5 2926#define SQLITE_LIMIT_FUNCTION_ARG 6 2927#define SQLITE_LIMIT_ATTACHED 7 2928#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2929#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2930#define SQLITE_LIMIT_TRIGGER_DEPTH 10 2931 2932/* 2933** CAPI3REF: Compiling An SQL Statement 2934** KEYWORDS: {SQL statement compiler} 2935** 2936** To execute an SQL query, it must first be compiled into a byte-code 2937** program using one of these routines. 2938** 2939** The first argument, "db", is a [database connection] obtained from a 2940** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 2941** [sqlite3_open16()]. The database connection must not have been closed. 2942** 2943** The second argument, "zSql", is the statement to be compiled, encoded 2944** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2945** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2946** use UTF-16. 2947** 2948** ^If the nByte argument is less than zero, then zSql is read up to the 2949** first zero terminator. ^If nByte is non-negative, then it is the maximum 2950** number of bytes read from zSql. ^When nByte is non-negative, the 2951** zSql string ends at either the first '\000' or '\u0000' character or 2952** the nByte-th byte, whichever comes first. If the caller knows 2953** that the supplied string is nul-terminated, then there is a small 2954** performance advantage to be gained by passing an nByte parameter that 2955** is equal to the number of bytes in the input string <i>including</i> 2956** the nul-terminator bytes as this saves SQLite from having to 2957** make a copy of the input string. 2958** 2959** ^If pzTail is not NULL then *pzTail is made to point to the first byte 2960** past the end of the first SQL statement in zSql. These routines only 2961** compile the first statement in zSql, so *pzTail is left pointing to 2962** what remains uncompiled. 2963** 2964** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 2965** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 2966** to NULL. ^If the input text contains no SQL (if the input is an empty 2967** string or a comment) then *ppStmt is set to NULL. 2968** The calling procedure is responsible for deleting the compiled 2969** SQL statement using [sqlite3_finalize()] after it has finished with it. 2970** ppStmt may not be NULL. 2971** 2972** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 2973** otherwise an [error code] is returned. 2974** 2975** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2976** recommended for all new programs. The two older interfaces are retained 2977** for backwards compatibility, but their use is discouraged. 2978** ^In the "v2" interfaces, the prepared statement 2979** that is returned (the [sqlite3_stmt] object) contains a copy of the 2980** original SQL text. This causes the [sqlite3_step()] interface to 2981** behave differently in three ways: 2982** 2983** <ol> 2984** <li> 2985** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2986** always used to do, [sqlite3_step()] will automatically recompile the SQL 2987** statement and try to run it again. 2988** </li> 2989** 2990** <li> 2991** ^When an error occurs, [sqlite3_step()] will return one of the detailed 2992** [error codes] or [extended error codes]. ^The legacy behavior was that 2993** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2994** and the application would have to make a second call to [sqlite3_reset()] 2995** in order to find the underlying cause of the problem. With the "v2" prepare 2996** interfaces, the underlying reason for the error is returned immediately. 2997** </li> 2998** 2999** <li> 3000** ^If the specific value bound to [parameter | host parameter] in the 3001** WHERE clause might influence the choice of query plan for a statement, 3002** then the statement will be automatically recompiled, as if there had been 3003** a schema change, on the first [sqlite3_step()] call following any change 3004** to the [sqlite3_bind_text | bindings] of that [parameter]. 3005** ^The specific value of WHERE-clause [parameter] might influence the 3006** choice of query plan if the parameter is the left-hand side of a [LIKE] 3007** or [GLOB] operator or if the parameter is compared to an indexed column 3008** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3009** the 3010** </li> 3011** </ol> 3012*/ 3013int sqlite3_prepare( 3014 sqlite3 *db, /* Database handle */ 3015 const char *zSql, /* SQL statement, UTF-8 encoded */ 3016 int nByte, /* Maximum length of zSql in bytes. */ 3017 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3018 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3019); 3020int sqlite3_prepare_v2( 3021 sqlite3 *db, /* Database handle */ 3022 const char *zSql, /* SQL statement, UTF-8 encoded */ 3023 int nByte, /* Maximum length of zSql in bytes. */ 3024 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3025 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3026); 3027int sqlite3_prepare16( 3028 sqlite3 *db, /* Database handle */ 3029 const void *zSql, /* SQL statement, UTF-16 encoded */ 3030 int nByte, /* Maximum length of zSql in bytes. */ 3031 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3032 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3033); 3034int sqlite3_prepare16_v2( 3035 sqlite3 *db, /* Database handle */ 3036 const void *zSql, /* SQL statement, UTF-16 encoded */ 3037 int nByte, /* Maximum length of zSql in bytes. */ 3038 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3039 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3040); 3041 3042/* 3043** CAPI3REF: Retrieving Statement SQL 3044** 3045** ^This interface can be used to retrieve a saved copy of the original 3046** SQL text used to create a [prepared statement] if that statement was 3047** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3048*/ 3049const char *sqlite3_sql(sqlite3_stmt *pStmt); 3050 3051/* 3052** CAPI3REF: Determine If An SQL Statement Writes The Database 3053** 3054** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3055** and only if the [prepared statement] X makes no direct changes to 3056** the content of the database file. 3057** 3058** Note that [application-defined SQL functions] or 3059** [virtual tables] might change the database indirectly as a side effect. 3060** ^(For example, if an application defines a function "eval()" that 3061** calls [sqlite3_exec()], then the following SQL statement would 3062** change the database file through side-effects: 3063** 3064** <blockquote><pre> 3065** SELECT eval('DELETE FROM t1') FROM t2; 3066** </pre></blockquote> 3067** 3068** But because the [SELECT] statement does not change the database file 3069** directly, sqlite3_stmt_readonly() would still return true.)^ 3070** 3071** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3072** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3073** since the statements themselves do not actually modify the database but 3074** rather they control the timing of when other statements modify the 3075** database. ^The [ATTACH] and [DETACH] statements also cause 3076** sqlite3_stmt_readonly() to return true since, while those statements 3077** change the configuration of a database connection, they do not make 3078** changes to the content of the database files on disk. 3079*/ 3080int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3081 3082/* 3083** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3084** 3085** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3086** [prepared statement] S has been stepped at least once using 3087** [sqlite3_step(S)] but has not run to completion and/or has not 3088** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3089** interface returns false if S is a NULL pointer. If S is not a 3090** NULL pointer and is not a pointer to a valid [prepared statement] 3091** object, then the behavior is undefined and probably undesirable. 3092** 3093** This interface can be used in combination [sqlite3_next_stmt()] 3094** to locate all prepared statements associated with a database 3095** connection that are in need of being reset. This can be used, 3096** for example, in diagnostic routines to search for prepared 3097** statements that are holding a transaction open. 3098*/ 3099int sqlite3_stmt_busy(sqlite3_stmt*); 3100 3101/* 3102** CAPI3REF: Dynamically Typed Value Object 3103** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3104** 3105** SQLite uses the sqlite3_value object to represent all values 3106** that can be stored in a database table. SQLite uses dynamic typing 3107** for the values it stores. ^Values stored in sqlite3_value objects 3108** can be integers, floating point values, strings, BLOBs, or NULL. 3109** 3110** An sqlite3_value object may be either "protected" or "unprotected". 3111** Some interfaces require a protected sqlite3_value. Other interfaces 3112** will accept either a protected or an unprotected sqlite3_value. 3113** Every interface that accepts sqlite3_value arguments specifies 3114** whether or not it requires a protected sqlite3_value. 3115** 3116** The terms "protected" and "unprotected" refer to whether or not 3117** a mutex is held. An internal mutex is held for a protected 3118** sqlite3_value object but no mutex is held for an unprotected 3119** sqlite3_value object. If SQLite is compiled to be single-threaded 3120** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3121** or if SQLite is run in one of reduced mutex modes 3122** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3123** then there is no distinction between protected and unprotected 3124** sqlite3_value objects and they can be used interchangeably. However, 3125** for maximum code portability it is recommended that applications 3126** still make the distinction between protected and unprotected 3127** sqlite3_value objects even when not strictly required. 3128** 3129** ^The sqlite3_value objects that are passed as parameters into the 3130** implementation of [application-defined SQL functions] are protected. 3131** ^The sqlite3_value object returned by 3132** [sqlite3_column_value()] is unprotected. 3133** Unprotected sqlite3_value objects may only be used with 3134** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3135** The [sqlite3_value_blob | sqlite3_value_type()] family of 3136** interfaces require protected sqlite3_value objects. 3137*/ 3138typedef struct Mem sqlite3_value; 3139 3140/* 3141** CAPI3REF: SQL Function Context Object 3142** 3143** The context in which an SQL function executes is stored in an 3144** sqlite3_context object. ^A pointer to an sqlite3_context object 3145** is always first parameter to [application-defined SQL functions]. 3146** The application-defined SQL function implementation will pass this 3147** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3148** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3149** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3150** and/or [sqlite3_set_auxdata()]. 3151*/ 3152typedef struct sqlite3_context sqlite3_context; 3153 3154/* 3155** CAPI3REF: Binding Values To Prepared Statements 3156** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3157** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3158** 3159** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3160** literals may be replaced by a [parameter] that matches one of following 3161** templates: 3162** 3163** <ul> 3164** <li> ? 3165** <li> ?NNN 3166** <li> :VVV 3167** <li> @VVV 3168** <li> $VVV 3169** </ul> 3170** 3171** In the templates above, NNN represents an integer literal, 3172** and VVV represents an alphanumeric identifier.)^ ^The values of these 3173** parameters (also called "host parameter names" or "SQL parameters") 3174** can be set using the sqlite3_bind_*() routines defined here. 3175** 3176** ^The first argument to the sqlite3_bind_*() routines is always 3177** a pointer to the [sqlite3_stmt] object returned from 3178** [sqlite3_prepare_v2()] or its variants. 3179** 3180** ^The second argument is the index of the SQL parameter to be set. 3181** ^The leftmost SQL parameter has an index of 1. ^When the same named 3182** SQL parameter is used more than once, second and subsequent 3183** occurrences have the same index as the first occurrence. 3184** ^The index for named parameters can be looked up using the 3185** [sqlite3_bind_parameter_index()] API if desired. ^The index 3186** for "?NNN" parameters is the value of NNN. 3187** ^The NNN value must be between 1 and the [sqlite3_limit()] 3188** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3189** 3190** ^The third argument is the value to bind to the parameter. 3191** 3192** ^(In those routines that have a fourth argument, its value is the 3193** number of bytes in the parameter. To be clear: the value is the 3194** number of <u>bytes</u> in the value, not the number of characters.)^ 3195** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3196** is negative, then the length of the string is 3197** the number of bytes up to the first zero terminator. 3198** If the fourth parameter to sqlite3_bind_blob() is negative, then 3199** the behavior is undefined. 3200** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3201** or sqlite3_bind_text16() then that parameter must be the byte offset 3202** where the NUL terminator would occur assuming the string were NUL 3203** terminated. If any NUL characters occur at byte offsets less than 3204** the value of the fourth parameter then the resulting string value will 3205** contain embedded NULs. The result of expressions involving strings 3206** with embedded NULs is undefined. 3207** 3208** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3209** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3210** string after SQLite has finished with it. ^The destructor is called 3211** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3212** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3213** ^If the fifth argument is 3214** the special value [SQLITE_STATIC], then SQLite assumes that the 3215** information is in static, unmanaged space and does not need to be freed. 3216** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3217** SQLite makes its own private copy of the data immediately, before 3218** the sqlite3_bind_*() routine returns. 3219** 3220** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3221** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3222** (just an integer to hold its size) while it is being processed. 3223** Zeroblobs are intended to serve as placeholders for BLOBs whose 3224** content is later written using 3225** [sqlite3_blob_open | incremental BLOB I/O] routines. 3226** ^A negative value for the zeroblob results in a zero-length BLOB. 3227** 3228** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3229** for the [prepared statement] or with a prepared statement for which 3230** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3231** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3232** routine is passed a [prepared statement] that has been finalized, the 3233** result is undefined and probably harmful. 3234** 3235** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3236** ^Unbound parameters are interpreted as NULL. 3237** 3238** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3239** [error code] if anything goes wrong. 3240** ^[SQLITE_RANGE] is returned if the parameter 3241** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3242** 3243** See also: [sqlite3_bind_parameter_count()], 3244** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3245*/ 3246int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3247int sqlite3_bind_double(sqlite3_stmt*, int, double); 3248int sqlite3_bind_int(sqlite3_stmt*, int, int); 3249int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3250int sqlite3_bind_null(sqlite3_stmt*, int); 3251int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3252int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3253int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3254int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3255 3256/* 3257** CAPI3REF: Number Of SQL Parameters 3258** 3259** ^This routine can be used to find the number of [SQL parameters] 3260** in a [prepared statement]. SQL parameters are tokens of the 3261** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3262** placeholders for values that are [sqlite3_bind_blob | bound] 3263** to the parameters at a later time. 3264** 3265** ^(This routine actually returns the index of the largest (rightmost) 3266** parameter. For all forms except ?NNN, this will correspond to the 3267** number of unique parameters. If parameters of the ?NNN form are used, 3268** there may be gaps in the list.)^ 3269** 3270** See also: [sqlite3_bind_blob|sqlite3_bind()], 3271** [sqlite3_bind_parameter_name()], and 3272** [sqlite3_bind_parameter_index()]. 3273*/ 3274int sqlite3_bind_parameter_count(sqlite3_stmt*); 3275 3276/* 3277** CAPI3REF: Name Of A Host Parameter 3278** 3279** ^The sqlite3_bind_parameter_name(P,N) interface returns 3280** the name of the N-th [SQL parameter] in the [prepared statement] P. 3281** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3282** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3283** respectively. 3284** In other words, the initial ":" or "$" or "@" or "?" 3285** is included as part of the name.)^ 3286** ^Parameters of the form "?" without a following integer have no name 3287** and are referred to as "nameless" or "anonymous parameters". 3288** 3289** ^The first host parameter has an index of 1, not 0. 3290** 3291** ^If the value N is out of range or if the N-th parameter is 3292** nameless, then NULL is returned. ^The returned string is 3293** always in UTF-8 encoding even if the named parameter was 3294** originally specified as UTF-16 in [sqlite3_prepare16()] or 3295** [sqlite3_prepare16_v2()]. 3296** 3297** See also: [sqlite3_bind_blob|sqlite3_bind()], 3298** [sqlite3_bind_parameter_count()], and 3299** [sqlite3_bind_parameter_index()]. 3300*/ 3301const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3302 3303/* 3304** CAPI3REF: Index Of A Parameter With A Given Name 3305** 3306** ^Return the index of an SQL parameter given its name. ^The 3307** index value returned is suitable for use as the second 3308** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3309** is returned if no matching parameter is found. ^The parameter 3310** name must be given in UTF-8 even if the original statement 3311** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3312** 3313** See also: [sqlite3_bind_blob|sqlite3_bind()], 3314** [sqlite3_bind_parameter_count()], and 3315** [sqlite3_bind_parameter_index()]. 3316*/ 3317int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3318 3319/* 3320** CAPI3REF: Reset All Bindings On A Prepared Statement 3321** 3322** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3323** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3324** ^Use this routine to reset all host parameters to NULL. 3325*/ 3326int sqlite3_clear_bindings(sqlite3_stmt*); 3327 3328/* 3329** CAPI3REF: Number Of Columns In A Result Set 3330** 3331** ^Return the number of columns in the result set returned by the 3332** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3333** statement that does not return data (for example an [UPDATE]). 3334** 3335** See also: [sqlite3_data_count()] 3336*/ 3337int sqlite3_column_count(sqlite3_stmt *pStmt); 3338 3339/* 3340** CAPI3REF: Column Names In A Result Set 3341** 3342** ^These routines return the name assigned to a particular column 3343** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3344** interface returns a pointer to a zero-terminated UTF-8 string 3345** and sqlite3_column_name16() returns a pointer to a zero-terminated 3346** UTF-16 string. ^The first parameter is the [prepared statement] 3347** that implements the [SELECT] statement. ^The second parameter is the 3348** column number. ^The leftmost column is number 0. 3349** 3350** ^The returned string pointer is valid until either the [prepared statement] 3351** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3352** reprepared by the first call to [sqlite3_step()] for a particular run 3353** or until the next call to 3354** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3355** 3356** ^If sqlite3_malloc() fails during the processing of either routine 3357** (for example during a conversion from UTF-8 to UTF-16) then a 3358** NULL pointer is returned. 3359** 3360** ^The name of a result column is the value of the "AS" clause for 3361** that column, if there is an AS clause. If there is no AS clause 3362** then the name of the column is unspecified and may change from 3363** one release of SQLite to the next. 3364*/ 3365const char *sqlite3_column_name(sqlite3_stmt*, int N); 3366const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3367 3368/* 3369** CAPI3REF: Source Of Data In A Query Result 3370** 3371** ^These routines provide a means to determine the database, table, and 3372** table column that is the origin of a particular result column in 3373** [SELECT] statement. 3374** ^The name of the database or table or column can be returned as 3375** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3376** the database name, the _table_ routines return the table name, and 3377** the origin_ routines return the column name. 3378** ^The returned string is valid until the [prepared statement] is destroyed 3379** using [sqlite3_finalize()] or until the statement is automatically 3380** reprepared by the first call to [sqlite3_step()] for a particular run 3381** or until the same information is requested 3382** again in a different encoding. 3383** 3384** ^The names returned are the original un-aliased names of the 3385** database, table, and column. 3386** 3387** ^The first argument to these interfaces is a [prepared statement]. 3388** ^These functions return information about the Nth result column returned by 3389** the statement, where N is the second function argument. 3390** ^The left-most column is column 0 for these routines. 3391** 3392** ^If the Nth column returned by the statement is an expression or 3393** subquery and is not a column value, then all of these functions return 3394** NULL. ^These routine might also return NULL if a memory allocation error 3395** occurs. ^Otherwise, they return the name of the attached database, table, 3396** or column that query result column was extracted from. 3397** 3398** ^As with all other SQLite APIs, those whose names end with "16" return 3399** UTF-16 encoded strings and the other functions return UTF-8. 3400** 3401** ^These APIs are only available if the library was compiled with the 3402** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3403** 3404** If two or more threads call one or more of these routines against the same 3405** prepared statement and column at the same time then the results are 3406** undefined. 3407** 3408** If two or more threads call one or more 3409** [sqlite3_column_database_name | column metadata interfaces] 3410** for the same [prepared statement] and result column 3411** at the same time then the results are undefined. 3412*/ 3413const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3414const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3415const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3416const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3417const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3418const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3419 3420/* 3421** CAPI3REF: Declared Datatype Of A Query Result 3422** 3423** ^(The first parameter is a [prepared statement]. 3424** If this statement is a [SELECT] statement and the Nth column of the 3425** returned result set of that [SELECT] is a table column (not an 3426** expression or subquery) then the declared type of the table 3427** column is returned.)^ ^If the Nth column of the result set is an 3428** expression or subquery, then a NULL pointer is returned. 3429** ^The returned string is always UTF-8 encoded. 3430** 3431** ^(For example, given the database schema: 3432** 3433** CREATE TABLE t1(c1 VARIANT); 3434** 3435** and the following statement to be compiled: 3436** 3437** SELECT c1 + 1, c1 FROM t1; 3438** 3439** this routine would return the string "VARIANT" for the second result 3440** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3441** 3442** ^SQLite uses dynamic run-time typing. ^So just because a column 3443** is declared to contain a particular type does not mean that the 3444** data stored in that column is of the declared type. SQLite is 3445** strongly typed, but the typing is dynamic not static. ^Type 3446** is associated with individual values, not with the containers 3447** used to hold those values. 3448*/ 3449const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3450const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3451 3452/* 3453** CAPI3REF: Evaluate An SQL Statement 3454** 3455** After a [prepared statement] has been prepared using either 3456** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3457** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3458** must be called one or more times to evaluate the statement. 3459** 3460** The details of the behavior of the sqlite3_step() interface depend 3461** on whether the statement was prepared using the newer "v2" interface 3462** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3463** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3464** new "v2" interface is recommended for new applications but the legacy 3465** interface will continue to be supported. 3466** 3467** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3468** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3469** ^With the "v2" interface, any of the other [result codes] or 3470** [extended result codes] might be returned as well. 3471** 3472** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3473** database locks it needs to do its job. ^If the statement is a [COMMIT] 3474** or occurs outside of an explicit transaction, then you can retry the 3475** statement. If the statement is not a [COMMIT] and occurs within an 3476** explicit transaction then you should rollback the transaction before 3477** continuing. 3478** 3479** ^[SQLITE_DONE] means that the statement has finished executing 3480** successfully. sqlite3_step() should not be called again on this virtual 3481** machine without first calling [sqlite3_reset()] to reset the virtual 3482** machine back to its initial state. 3483** 3484** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3485** is returned each time a new row of data is ready for processing by the 3486** caller. The values may be accessed using the [column access functions]. 3487** sqlite3_step() is called again to retrieve the next row of data. 3488** 3489** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3490** violation) has occurred. sqlite3_step() should not be called again on 3491** the VM. More information may be found by calling [sqlite3_errmsg()]. 3492** ^With the legacy interface, a more specific error code (for example, 3493** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3494** can be obtained by calling [sqlite3_reset()] on the 3495** [prepared statement]. ^In the "v2" interface, 3496** the more specific error code is returned directly by sqlite3_step(). 3497** 3498** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3499** Perhaps it was called on a [prepared statement] that has 3500** already been [sqlite3_finalize | finalized] or on one that had 3501** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3502** be the case that the same database connection is being used by two or 3503** more threads at the same moment in time. 3504** 3505** For all versions of SQLite up to and including 3.6.23.1, a call to 3506** [sqlite3_reset()] was required after sqlite3_step() returned anything 3507** other than [SQLITE_ROW] before any subsequent invocation of 3508** sqlite3_step(). Failure to reset the prepared statement using 3509** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3510** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3511** calling [sqlite3_reset()] automatically in this circumstance rather 3512** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3513** break because any application that ever receives an SQLITE_MISUSE error 3514** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3515** can be used to restore the legacy behavior. 3516** 3517** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3518** API always returns a generic error code, [SQLITE_ERROR], following any 3519** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3520** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3521** specific [error codes] that better describes the error. 3522** We admit that this is a goofy design. The problem has been fixed 3523** with the "v2" interface. If you prepare all of your SQL statements 3524** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3525** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3526** then the more specific [error codes] are returned directly 3527** by sqlite3_step(). The use of the "v2" interface is recommended. 3528*/ 3529int sqlite3_step(sqlite3_stmt*); 3530 3531/* 3532** CAPI3REF: Number of columns in a result set 3533** 3534** ^The sqlite3_data_count(P) interface returns the number of columns in the 3535** current row of the result set of [prepared statement] P. 3536** ^If prepared statement P does not have results ready to return 3537** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3538** interfaces) then sqlite3_data_count(P) returns 0. 3539** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3540** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3541** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3542** will return non-zero if previous call to [sqlite3_step](P) returned 3543** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3544** where it always returns zero since each step of that multi-step 3545** pragma returns 0 columns of data. 3546** 3547** See also: [sqlite3_column_count()] 3548*/ 3549int sqlite3_data_count(sqlite3_stmt *pStmt); 3550 3551/* 3552** CAPI3REF: Fundamental Datatypes 3553** KEYWORDS: SQLITE_TEXT 3554** 3555** ^(Every value in SQLite has one of five fundamental datatypes: 3556** 3557** <ul> 3558** <li> 64-bit signed integer 3559** <li> 64-bit IEEE floating point number 3560** <li> string 3561** <li> BLOB 3562** <li> NULL 3563** </ul>)^ 3564** 3565** These constants are codes for each of those types. 3566** 3567** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3568** for a completely different meaning. Software that links against both 3569** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3570** SQLITE_TEXT. 3571*/ 3572#define SQLITE_INTEGER 1 3573#define SQLITE_FLOAT 2 3574#define SQLITE_BLOB 4 3575#define SQLITE_NULL 5 3576#ifdef SQLITE_TEXT 3577# undef SQLITE_TEXT 3578#else 3579# define SQLITE_TEXT 3 3580#endif 3581#define SQLITE3_TEXT 3 3582 3583/* 3584** CAPI3REF: Result Values From A Query 3585** KEYWORDS: {column access functions} 3586** 3587** These routines form the "result set" interface. 3588** 3589** ^These routines return information about a single column of the current 3590** result row of a query. ^In every case the first argument is a pointer 3591** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3592** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3593** and the second argument is the index of the column for which information 3594** should be returned. ^The leftmost column of the result set has the index 0. 3595** ^The number of columns in the result can be determined using 3596** [sqlite3_column_count()]. 3597** 3598** If the SQL statement does not currently point to a valid row, or if the 3599** column index is out of range, the result is undefined. 3600** These routines may only be called when the most recent call to 3601** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3602** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3603** If any of these routines are called after [sqlite3_reset()] or 3604** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3605** something other than [SQLITE_ROW], the results are undefined. 3606** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3607** are called from a different thread while any of these routines 3608** are pending, then the results are undefined. 3609** 3610** ^The sqlite3_column_type() routine returns the 3611** [SQLITE_INTEGER | datatype code] for the initial data type 3612** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3613** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3614** returned by sqlite3_column_type() is only meaningful if no type 3615** conversions have occurred as described below. After a type conversion, 3616** the value returned by sqlite3_column_type() is undefined. Future 3617** versions of SQLite may change the behavior of sqlite3_column_type() 3618** following a type conversion. 3619** 3620** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3621** routine returns the number of bytes in that BLOB or string. 3622** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3623** the string to UTF-8 and then returns the number of bytes. 3624** ^If the result is a numeric value then sqlite3_column_bytes() uses 3625** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3626** the number of bytes in that string. 3627** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3628** 3629** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3630** routine returns the number of bytes in that BLOB or string. 3631** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3632** the string to UTF-16 and then returns the number of bytes. 3633** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3634** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3635** the number of bytes in that string. 3636** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3637** 3638** ^The values returned by [sqlite3_column_bytes()] and 3639** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3640** of the string. ^For clarity: the values returned by 3641** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3642** bytes in the string, not the number of characters. 3643** 3644** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3645** even empty strings, are always zero-terminated. ^The return 3646** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3647** 3648** ^The object returned by [sqlite3_column_value()] is an 3649** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3650** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3651** If the [unprotected sqlite3_value] object returned by 3652** [sqlite3_column_value()] is used in any other way, including calls 3653** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3654** or [sqlite3_value_bytes()], then the behavior is undefined. 3655** 3656** These routines attempt to convert the value where appropriate. ^For 3657** example, if the internal representation is FLOAT and a text result 3658** is requested, [sqlite3_snprintf()] is used internally to perform the 3659** conversion automatically. ^(The following table details the conversions 3660** that are applied: 3661** 3662** <blockquote> 3663** <table border="1"> 3664** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3665** 3666** <tr><td> NULL <td> INTEGER <td> Result is 0 3667** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3668** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3669** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3670** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3671** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3672** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3673** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3674** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3675** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3676** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3677** <tr><td> TEXT <td> FLOAT <td> Use atof() 3678** <tr><td> TEXT <td> BLOB <td> No change 3679** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3680** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3681** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3682** </table> 3683** </blockquote>)^ 3684** 3685** The table above makes reference to standard C library functions atoi() 3686** and atof(). SQLite does not really use these functions. It has its 3687** own equivalent internal routines. The atoi() and atof() names are 3688** used in the table for brevity and because they are familiar to most 3689** C programmers. 3690** 3691** Note that when type conversions occur, pointers returned by prior 3692** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3693** sqlite3_column_text16() may be invalidated. 3694** Type conversions and pointer invalidations might occur 3695** in the following cases: 3696** 3697** <ul> 3698** <li> The initial content is a BLOB and sqlite3_column_text() or 3699** sqlite3_column_text16() is called. A zero-terminator might 3700** need to be added to the string.</li> 3701** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3702** sqlite3_column_text16() is called. The content must be converted 3703** to UTF-16.</li> 3704** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3705** sqlite3_column_text() is called. The content must be converted 3706** to UTF-8.</li> 3707** </ul> 3708** 3709** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3710** not invalidate a prior pointer, though of course the content of the buffer 3711** that the prior pointer references will have been modified. Other kinds 3712** of conversion are done in place when it is possible, but sometimes they 3713** are not possible and in those cases prior pointers are invalidated. 3714** 3715** The safest and easiest to remember policy is to invoke these routines 3716** in one of the following ways: 3717** 3718** <ul> 3719** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3720** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3721** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3722** </ul> 3723** 3724** In other words, you should call sqlite3_column_text(), 3725** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3726** into the desired format, then invoke sqlite3_column_bytes() or 3727** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3728** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3729** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3730** with calls to sqlite3_column_bytes(). 3731** 3732** ^The pointers returned are valid until a type conversion occurs as 3733** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3734** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3735** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3736** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3737** [sqlite3_free()]. 3738** 3739** ^(If a memory allocation error occurs during the evaluation of any 3740** of these routines, a default value is returned. The default value 3741** is either the integer 0, the floating point number 0.0, or a NULL 3742** pointer. Subsequent calls to [sqlite3_errcode()] will return 3743** [SQLITE_NOMEM].)^ 3744*/ 3745const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3746int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3747int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3748double sqlite3_column_double(sqlite3_stmt*, int iCol); 3749int sqlite3_column_int(sqlite3_stmt*, int iCol); 3750sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3751const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3752const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3753int sqlite3_column_type(sqlite3_stmt*, int iCol); 3754sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3755 3756/* 3757** CAPI3REF: Destroy A Prepared Statement Object 3758** 3759** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3760** ^If the most recent evaluation of the statement encountered no errors 3761** or if the statement is never been evaluated, then sqlite3_finalize() returns 3762** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3763** sqlite3_finalize(S) returns the appropriate [error code] or 3764** [extended error code]. 3765** 3766** ^The sqlite3_finalize(S) routine can be called at any point during 3767** the life cycle of [prepared statement] S: 3768** before statement S is ever evaluated, after 3769** one or more calls to [sqlite3_reset()], or after any call 3770** to [sqlite3_step()] regardless of whether or not the statement has 3771** completed execution. 3772** 3773** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3774** 3775** The application must finalize every [prepared statement] in order to avoid 3776** resource leaks. It is a grievous error for the application to try to use 3777** a prepared statement after it has been finalized. Any use of a prepared 3778** statement after it has been finalized can result in undefined and 3779** undesirable behavior such as segfaults and heap corruption. 3780*/ 3781int sqlite3_finalize(sqlite3_stmt *pStmt); 3782 3783/* 3784** CAPI3REF: Reset A Prepared Statement Object 3785** 3786** The sqlite3_reset() function is called to reset a [prepared statement] 3787** object back to its initial state, ready to be re-executed. 3788** ^Any SQL statement variables that had values bound to them using 3789** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3790** Use [sqlite3_clear_bindings()] to reset the bindings. 3791** 3792** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3793** back to the beginning of its program. 3794** 3795** ^If the most recent call to [sqlite3_step(S)] for the 3796** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3797** or if [sqlite3_step(S)] has never before been called on S, 3798** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3799** 3800** ^If the most recent call to [sqlite3_step(S)] for the 3801** [prepared statement] S indicated an error, then 3802** [sqlite3_reset(S)] returns an appropriate [error code]. 3803** 3804** ^The [sqlite3_reset(S)] interface does not change the values 3805** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3806*/ 3807int sqlite3_reset(sqlite3_stmt *pStmt); 3808 3809/* 3810** CAPI3REF: Create Or Redefine SQL Functions 3811** KEYWORDS: {function creation routines} 3812** KEYWORDS: {application-defined SQL function} 3813** KEYWORDS: {application-defined SQL functions} 3814** 3815** ^These functions (collectively known as "function creation routines") 3816** are used to add SQL functions or aggregates or to redefine the behavior 3817** of existing SQL functions or aggregates. The only differences between 3818** these routines are the text encoding expected for 3819** the second parameter (the name of the function being created) 3820** and the presence or absence of a destructor callback for 3821** the application data pointer. 3822** 3823** ^The first parameter is the [database connection] to which the SQL 3824** function is to be added. ^If an application uses more than one database 3825** connection then application-defined SQL functions must be added 3826** to each database connection separately. 3827** 3828** ^The second parameter is the name of the SQL function to be created or 3829** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3830** representation, exclusive of the zero-terminator. ^Note that the name 3831** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3832** ^Any attempt to create a function with a longer name 3833** will result in [SQLITE_MISUSE] being returned. 3834** 3835** ^The third parameter (nArg) 3836** is the number of arguments that the SQL function or 3837** aggregate takes. ^If this parameter is -1, then the SQL function or 3838** aggregate may take any number of arguments between 0 and the limit 3839** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3840** parameter is less than -1 or greater than 127 then the behavior is 3841** undefined. 3842** 3843** ^The fourth parameter, eTextRep, specifies what 3844** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3845** its parameters. Every SQL function implementation must be able to work 3846** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3847** more efficient with one encoding than another. ^An application may 3848** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3849** times with the same function but with different values of eTextRep. 3850** ^When multiple implementations of the same function are available, SQLite 3851** will pick the one that involves the least amount of data conversion. 3852** If there is only a single implementation which does not care what text 3853** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3854** 3855** ^(The fifth parameter is an arbitrary pointer. The implementation of the 3856** function can gain access to this pointer using [sqlite3_user_data()].)^ 3857** 3858** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 3859** pointers to C-language functions that implement the SQL function or 3860** aggregate. ^A scalar SQL function requires an implementation of the xFunc 3861** callback only; NULL pointers must be passed as the xStep and xFinal 3862** parameters. ^An aggregate SQL function requires an implementation of xStep 3863** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 3864** SQL function or aggregate, pass NULL pointers for all three function 3865** callbacks. 3866** 3867** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 3868** then it is destructor for the application data pointer. 3869** The destructor is invoked when the function is deleted, either by being 3870** overloaded or when the database connection closes.)^ 3871** ^The destructor is also invoked if the call to 3872** sqlite3_create_function_v2() fails. 3873** ^When the destructor callback of the tenth parameter is invoked, it 3874** is passed a single argument which is a copy of the application data 3875** pointer which was the fifth parameter to sqlite3_create_function_v2(). 3876** 3877** ^It is permitted to register multiple implementations of the same 3878** functions with the same name but with either differing numbers of 3879** arguments or differing preferred text encodings. ^SQLite will use 3880** the implementation that most closely matches the way in which the 3881** SQL function is used. ^A function implementation with a non-negative 3882** nArg parameter is a better match than a function implementation with 3883** a negative nArg. ^A function where the preferred text encoding 3884** matches the database encoding is a better 3885** match than a function where the encoding is different. 3886** ^A function where the encoding difference is between UTF16le and UTF16be 3887** is a closer match than a function where the encoding difference is 3888** between UTF8 and UTF16. 3889** 3890** ^Built-in functions may be overloaded by new application-defined functions. 3891** 3892** ^An application-defined function is permitted to call other 3893** SQLite interfaces. However, such calls must not 3894** close the database connection nor finalize or reset the prepared 3895** statement in which the function is running. 3896*/ 3897int sqlite3_create_function( 3898 sqlite3 *db, 3899 const char *zFunctionName, 3900 int nArg, 3901 int eTextRep, 3902 void *pApp, 3903 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3904 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3905 void (*xFinal)(sqlite3_context*) 3906); 3907int sqlite3_create_function16( 3908 sqlite3 *db, 3909 const void *zFunctionName, 3910 int nArg, 3911 int eTextRep, 3912 void *pApp, 3913 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3914 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3915 void (*xFinal)(sqlite3_context*) 3916); 3917int sqlite3_create_function_v2( 3918 sqlite3 *db, 3919 const char *zFunctionName, 3920 int nArg, 3921 int eTextRep, 3922 void *pApp, 3923 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3924 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3925 void (*xFinal)(sqlite3_context*), 3926 void(*xDestroy)(void*) 3927); 3928 3929/* 3930** CAPI3REF: Text Encodings 3931** 3932** These constant define integer codes that represent the various 3933** text encodings supported by SQLite. 3934*/ 3935#define SQLITE_UTF8 1 3936#define SQLITE_UTF16LE 2 3937#define SQLITE_UTF16BE 3 3938#define SQLITE_UTF16 4 /* Use native byte order */ 3939#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3940#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3941 3942/* 3943** CAPI3REF: Deprecated Functions 3944** DEPRECATED 3945** 3946** These functions are [deprecated]. In order to maintain 3947** backwards compatibility with older code, these functions continue 3948** to be supported. However, new applications should avoid 3949** the use of these functions. To help encourage people to avoid 3950** using these functions, we are not going to tell you what they do. 3951*/ 3952#ifndef SQLITE_OMIT_DEPRECATED 3953SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3954SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3955SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3956SQLITE_DEPRECATED int sqlite3_global_recover(void); 3957SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3958SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3959#endif 3960 3961/* 3962** CAPI3REF: Obtaining SQL Function Parameter Values 3963** 3964** The C-language implementation of SQL functions and aggregates uses 3965** this set of interface routines to access the parameter values on 3966** the function or aggregate. 3967** 3968** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3969** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3970** define callbacks that implement the SQL functions and aggregates. 3971** The 3rd parameter to these callbacks is an array of pointers to 3972** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3973** each parameter to the SQL function. These routines are used to 3974** extract values from the [sqlite3_value] objects. 3975** 3976** These routines work only with [protected sqlite3_value] objects. 3977** Any attempt to use these routines on an [unprotected sqlite3_value] 3978** object results in undefined behavior. 3979** 3980** ^These routines work just like the corresponding [column access functions] 3981** except that these routines take a single [protected sqlite3_value] object 3982** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3983** 3984** ^The sqlite3_value_text16() interface extracts a UTF-16 string 3985** in the native byte-order of the host machine. ^The 3986** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3987** extract UTF-16 strings as big-endian and little-endian respectively. 3988** 3989** ^(The sqlite3_value_numeric_type() interface attempts to apply 3990** numeric affinity to the value. This means that an attempt is 3991** made to convert the value to an integer or floating point. If 3992** such a conversion is possible without loss of information (in other 3993** words, if the value is a string that looks like a number) 3994** then the conversion is performed. Otherwise no conversion occurs. 3995** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 3996** 3997** Please pay particular attention to the fact that the pointer returned 3998** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3999** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4000** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4001** or [sqlite3_value_text16()]. 4002** 4003** These routines must be called from the same thread as 4004** the SQL function that supplied the [sqlite3_value*] parameters. 4005*/ 4006const void *sqlite3_value_blob(sqlite3_value*); 4007int sqlite3_value_bytes(sqlite3_value*); 4008int sqlite3_value_bytes16(sqlite3_value*); 4009double sqlite3_value_double(sqlite3_value*); 4010int sqlite3_value_int(sqlite3_value*); 4011sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4012const unsigned char *sqlite3_value_text(sqlite3_value*); 4013const void *sqlite3_value_text16(sqlite3_value*); 4014const void *sqlite3_value_text16le(sqlite3_value*); 4015const void *sqlite3_value_text16be(sqlite3_value*); 4016int sqlite3_value_type(sqlite3_value*); 4017int sqlite3_value_numeric_type(sqlite3_value*); 4018 4019/* 4020** CAPI3REF: Obtain Aggregate Function Context 4021** 4022** Implementations of aggregate SQL functions use this 4023** routine to allocate memory for storing their state. 4024** 4025** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4026** for a particular aggregate function, SQLite 4027** allocates N of memory, zeroes out that memory, and returns a pointer 4028** to the new memory. ^On second and subsequent calls to 4029** sqlite3_aggregate_context() for the same aggregate function instance, 4030** the same buffer is returned. Sqlite3_aggregate_context() is normally 4031** called once for each invocation of the xStep callback and then one 4032** last time when the xFinal callback is invoked. ^(When no rows match 4033** an aggregate query, the xStep() callback of the aggregate function 4034** implementation is never called and xFinal() is called exactly once. 4035** In those cases, sqlite3_aggregate_context() might be called for the 4036** first time from within xFinal().)^ 4037** 4038** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is 4039** less than or equal to zero or if a memory allocate error occurs. 4040** 4041** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4042** determined by the N parameter on first successful call. Changing the 4043** value of N in subsequent call to sqlite3_aggregate_context() within 4044** the same aggregate function instance will not resize the memory 4045** allocation.)^ 4046** 4047** ^SQLite automatically frees the memory allocated by 4048** sqlite3_aggregate_context() when the aggregate query concludes. 4049** 4050** The first parameter must be a copy of the 4051** [sqlite3_context | SQL function context] that is the first parameter 4052** to the xStep or xFinal callback routine that implements the aggregate 4053** function. 4054** 4055** This routine must be called from the same thread in which 4056** the aggregate SQL function is running. 4057*/ 4058void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4059 4060/* 4061** CAPI3REF: User Data For Functions 4062** 4063** ^The sqlite3_user_data() interface returns a copy of 4064** the pointer that was the pUserData parameter (the 5th parameter) 4065** of the [sqlite3_create_function()] 4066** and [sqlite3_create_function16()] routines that originally 4067** registered the application defined function. 4068** 4069** This routine must be called from the same thread in which 4070** the application-defined function is running. 4071*/ 4072void *sqlite3_user_data(sqlite3_context*); 4073 4074/* 4075** CAPI3REF: Database Connection For Functions 4076** 4077** ^The sqlite3_context_db_handle() interface returns a copy of 4078** the pointer to the [database connection] (the 1st parameter) 4079** of the [sqlite3_create_function()] 4080** and [sqlite3_create_function16()] routines that originally 4081** registered the application defined function. 4082*/ 4083sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4084 4085/* 4086** CAPI3REF: Function Auxiliary Data 4087** 4088** The following two functions may be used by scalar SQL functions to 4089** associate metadata with argument values. If the same value is passed to 4090** multiple invocations of the same SQL function during query execution, under 4091** some circumstances the associated metadata may be preserved. This may 4092** be used, for example, to add a regular-expression matching scalar 4093** function. The compiled version of the regular expression is stored as 4094** metadata associated with the SQL value passed as the regular expression 4095** pattern. The compiled regular expression can be reused on multiple 4096** invocations of the same function so that the original pattern string 4097** does not need to be recompiled on each invocation. 4098** 4099** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4100** associated by the sqlite3_set_auxdata() function with the Nth argument 4101** value to the application-defined function. ^If no metadata has been ever 4102** been set for the Nth argument of the function, or if the corresponding 4103** function parameter has changed since the meta-data was set, 4104** then sqlite3_get_auxdata() returns a NULL pointer. 4105** 4106** ^The sqlite3_set_auxdata() interface saves the metadata 4107** pointed to by its 3rd parameter as the metadata for the N-th 4108** argument of the application-defined function. Subsequent 4109** calls to sqlite3_get_auxdata() might return this data, if it has 4110** not been destroyed. 4111** ^If it is not NULL, SQLite will invoke the destructor 4112** function given by the 4th parameter to sqlite3_set_auxdata() on 4113** the metadata when the corresponding function parameter changes 4114** or when the SQL statement completes, whichever comes first. 4115** 4116** SQLite is free to call the destructor and drop metadata on any 4117** parameter of any function at any time. ^The only guarantee is that 4118** the destructor will be called before the metadata is dropped. 4119** 4120** ^(In practice, metadata is preserved between function calls for 4121** expressions that are constant at compile time. This includes literal 4122** values and [parameters].)^ 4123** 4124** These routines must be called from the same thread in which 4125** the SQL function is running. 4126*/ 4127void *sqlite3_get_auxdata(sqlite3_context*, int N); 4128void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4129 4130 4131/* 4132** CAPI3REF: Constants Defining Special Destructor Behavior 4133** 4134** These are special values for the destructor that is passed in as the 4135** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4136** argument is SQLITE_STATIC, it means that the content pointer is constant 4137** and will never change. It does not need to be destroyed. ^The 4138** SQLITE_TRANSIENT value means that the content will likely change in 4139** the near future and that SQLite should make its own private copy of 4140** the content before returning. 4141** 4142** The typedef is necessary to work around problems in certain 4143** C++ compilers. See ticket #2191. 4144*/ 4145typedef void (*sqlite3_destructor_type)(void*); 4146#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4147#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4148 4149/* 4150** CAPI3REF: Setting The Result Of An SQL Function 4151** 4152** These routines are used by the xFunc or xFinal callbacks that 4153** implement SQL functions and aggregates. See 4154** [sqlite3_create_function()] and [sqlite3_create_function16()] 4155** for additional information. 4156** 4157** These functions work very much like the [parameter binding] family of 4158** functions used to bind values to host parameters in prepared statements. 4159** Refer to the [SQL parameter] documentation for additional information. 4160** 4161** ^The sqlite3_result_blob() interface sets the result from 4162** an application-defined function to be the BLOB whose content is pointed 4163** to by the second parameter and which is N bytes long where N is the 4164** third parameter. 4165** 4166** ^The sqlite3_result_zeroblob() interfaces set the result of 4167** the application-defined function to be a BLOB containing all zero 4168** bytes and N bytes in size, where N is the value of the 2nd parameter. 4169** 4170** ^The sqlite3_result_double() interface sets the result from 4171** an application-defined function to be a floating point value specified 4172** by its 2nd argument. 4173** 4174** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4175** cause the implemented SQL function to throw an exception. 4176** ^SQLite uses the string pointed to by the 4177** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4178** as the text of an error message. ^SQLite interprets the error 4179** message string from sqlite3_result_error() as UTF-8. ^SQLite 4180** interprets the string from sqlite3_result_error16() as UTF-16 in native 4181** byte order. ^If the third parameter to sqlite3_result_error() 4182** or sqlite3_result_error16() is negative then SQLite takes as the error 4183** message all text up through the first zero character. 4184** ^If the third parameter to sqlite3_result_error() or 4185** sqlite3_result_error16() is non-negative then SQLite takes that many 4186** bytes (not characters) from the 2nd parameter as the error message. 4187** ^The sqlite3_result_error() and sqlite3_result_error16() 4188** routines make a private copy of the error message text before 4189** they return. Hence, the calling function can deallocate or 4190** modify the text after they return without harm. 4191** ^The sqlite3_result_error_code() function changes the error code 4192** returned by SQLite as a result of an error in a function. ^By default, 4193** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4194** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4195** 4196** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4197** error indicating that a string or BLOB is too long to represent. 4198** 4199** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4200** error indicating that a memory allocation failed. 4201** 4202** ^The sqlite3_result_int() interface sets the return value 4203** of the application-defined function to be the 32-bit signed integer 4204** value given in the 2nd argument. 4205** ^The sqlite3_result_int64() interface sets the return value 4206** of the application-defined function to be the 64-bit signed integer 4207** value given in the 2nd argument. 4208** 4209** ^The sqlite3_result_null() interface sets the return value 4210** of the application-defined function to be NULL. 4211** 4212** ^The sqlite3_result_text(), sqlite3_result_text16(), 4213** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4214** set the return value of the application-defined function to be 4215** a text string which is represented as UTF-8, UTF-16 native byte order, 4216** UTF-16 little endian, or UTF-16 big endian, respectively. 4217** ^SQLite takes the text result from the application from 4218** the 2nd parameter of the sqlite3_result_text* interfaces. 4219** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4220** is negative, then SQLite takes result text from the 2nd parameter 4221** through the first zero character. 4222** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4223** is non-negative, then as many bytes (not characters) of the text 4224** pointed to by the 2nd parameter are taken as the application-defined 4225** function result. If the 3rd parameter is non-negative, then it 4226** must be the byte offset into the string where the NUL terminator would 4227** appear if the string where NUL terminated. If any NUL characters occur 4228** in the string at a byte offset that is less than the value of the 3rd 4229** parameter, then the resulting string will contain embedded NULs and the 4230** result of expressions operating on strings with embedded NULs is undefined. 4231** ^If the 4th parameter to the sqlite3_result_text* interfaces 4232** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4233** function as the destructor on the text or BLOB result when it has 4234** finished using that result. 4235** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4236** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4237** assumes that the text or BLOB result is in constant space and does not 4238** copy the content of the parameter nor call a destructor on the content 4239** when it has finished using that result. 4240** ^If the 4th parameter to the sqlite3_result_text* interfaces 4241** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4242** then SQLite makes a copy of the result into space obtained from 4243** from [sqlite3_malloc()] before it returns. 4244** 4245** ^The sqlite3_result_value() interface sets the result of 4246** the application-defined function to be a copy the 4247** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4248** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4249** so that the [sqlite3_value] specified in the parameter may change or 4250** be deallocated after sqlite3_result_value() returns without harm. 4251** ^A [protected sqlite3_value] object may always be used where an 4252** [unprotected sqlite3_value] object is required, so either 4253** kind of [sqlite3_value] object can be used with this interface. 4254** 4255** If these routines are called from within the different thread 4256** than the one containing the application-defined function that received 4257** the [sqlite3_context] pointer, the results are undefined. 4258*/ 4259void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4260void sqlite3_result_double(sqlite3_context*, double); 4261void sqlite3_result_error(sqlite3_context*, const char*, int); 4262void sqlite3_result_error16(sqlite3_context*, const void*, int); 4263void sqlite3_result_error_toobig(sqlite3_context*); 4264void sqlite3_result_error_nomem(sqlite3_context*); 4265void sqlite3_result_error_code(sqlite3_context*, int); 4266void sqlite3_result_int(sqlite3_context*, int); 4267void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4268void sqlite3_result_null(sqlite3_context*); 4269void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4270void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4271void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4272void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4273void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4274void sqlite3_result_zeroblob(sqlite3_context*, int n); 4275 4276/* 4277** CAPI3REF: Define New Collating Sequences 4278** 4279** ^These functions add, remove, or modify a [collation] associated 4280** with the [database connection] specified as the first argument. 4281** 4282** ^The name of the collation is a UTF-8 string 4283** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4284** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4285** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4286** considered to be the same name. 4287** 4288** ^(The third argument (eTextRep) must be one of the constants: 4289** <ul> 4290** <li> [SQLITE_UTF8], 4291** <li> [SQLITE_UTF16LE], 4292** <li> [SQLITE_UTF16BE], 4293** <li> [SQLITE_UTF16], or 4294** <li> [SQLITE_UTF16_ALIGNED]. 4295** </ul>)^ 4296** ^The eTextRep argument determines the encoding of strings passed 4297** to the collating function callback, xCallback. 4298** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4299** force strings to be UTF16 with native byte order. 4300** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4301** on an even byte address. 4302** 4303** ^The fourth argument, pArg, is an application data pointer that is passed 4304** through as the first argument to the collating function callback. 4305** 4306** ^The fifth argument, xCallback, is a pointer to the collating function. 4307** ^Multiple collating functions can be registered using the same name but 4308** with different eTextRep parameters and SQLite will use whichever 4309** function requires the least amount of data transformation. 4310** ^If the xCallback argument is NULL then the collating function is 4311** deleted. ^When all collating functions having the same name are deleted, 4312** that collation is no longer usable. 4313** 4314** ^The collating function callback is invoked with a copy of the pArg 4315** application data pointer and with two strings in the encoding specified 4316** by the eTextRep argument. The collating function must return an 4317** integer that is negative, zero, or positive 4318** if the first string is less than, equal to, or greater than the second, 4319** respectively. A collating function must always return the same answer 4320** given the same inputs. If two or more collating functions are registered 4321** to the same collation name (using different eTextRep values) then all 4322** must give an equivalent answer when invoked with equivalent strings. 4323** The collating function must obey the following properties for all 4324** strings A, B, and C: 4325** 4326** <ol> 4327** <li> If A==B then B==A. 4328** <li> If A==B and B==C then A==C. 4329** <li> If A<B THEN B>A. 4330** <li> If A<B and B<C then A<C. 4331** </ol> 4332** 4333** If a collating function fails any of the above constraints and that 4334** collating function is registered and used, then the behavior of SQLite 4335** is undefined. 4336** 4337** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4338** with the addition that the xDestroy callback is invoked on pArg when 4339** the collating function is deleted. 4340** ^Collating functions are deleted when they are overridden by later 4341** calls to the collation creation functions or when the 4342** [database connection] is closed using [sqlite3_close()]. 4343** 4344** ^The xDestroy callback is <u>not</u> called if the 4345** sqlite3_create_collation_v2() function fails. Applications that invoke 4346** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4347** check the return code and dispose of the application data pointer 4348** themselves rather than expecting SQLite to deal with it for them. 4349** This is different from every other SQLite interface. The inconsistency 4350** is unfortunate but cannot be changed without breaking backwards 4351** compatibility. 4352** 4353** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4354*/ 4355int sqlite3_create_collation( 4356 sqlite3*, 4357 const char *zName, 4358 int eTextRep, 4359 void *pArg, 4360 int(*xCompare)(void*,int,const void*,int,const void*) 4361); 4362int sqlite3_create_collation_v2( 4363 sqlite3*, 4364 const char *zName, 4365 int eTextRep, 4366 void *pArg, 4367 int(*xCompare)(void*,int,const void*,int,const void*), 4368 void(*xDestroy)(void*) 4369); 4370int sqlite3_create_collation16( 4371 sqlite3*, 4372 const void *zName, 4373 int eTextRep, 4374 void *pArg, 4375 int(*xCompare)(void*,int,const void*,int,const void*) 4376); 4377 4378/* 4379** CAPI3REF: Collation Needed Callbacks 4380** 4381** ^To avoid having to register all collation sequences before a database 4382** can be used, a single callback function may be registered with the 4383** [database connection] to be invoked whenever an undefined collation 4384** sequence is required. 4385** 4386** ^If the function is registered using the sqlite3_collation_needed() API, 4387** then it is passed the names of undefined collation sequences as strings 4388** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4389** the names are passed as UTF-16 in machine native byte order. 4390** ^A call to either function replaces the existing collation-needed callback. 4391** 4392** ^(When the callback is invoked, the first argument passed is a copy 4393** of the second argument to sqlite3_collation_needed() or 4394** sqlite3_collation_needed16(). The second argument is the database 4395** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4396** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4397** sequence function required. The fourth parameter is the name of the 4398** required collation sequence.)^ 4399** 4400** The callback function should register the desired collation using 4401** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4402** [sqlite3_create_collation_v2()]. 4403*/ 4404int sqlite3_collation_needed( 4405 sqlite3*, 4406 void*, 4407 void(*)(void*,sqlite3*,int eTextRep,const char*) 4408); 4409int sqlite3_collation_needed16( 4410 sqlite3*, 4411 void*, 4412 void(*)(void*,sqlite3*,int eTextRep,const void*) 4413); 4414 4415#ifdef SQLITE_HAS_CODEC 4416/* 4417** Specify the key for an encrypted database. This routine should be 4418** called right after sqlite3_open(). 4419** 4420** The code to implement this API is not available in the public release 4421** of SQLite. 4422*/ 4423int sqlite3_key( 4424 sqlite3 *db, /* Database to be rekeyed */ 4425 const void *pKey, int nKey /* The key */ 4426); 4427 4428/* 4429** Change the key on an open database. If the current database is not 4430** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4431** database is decrypted. 4432** 4433** The code to implement this API is not available in the public release 4434** of SQLite. 4435*/ 4436int sqlite3_rekey( 4437 sqlite3 *db, /* Database to be rekeyed */ 4438 const void *pKey, int nKey /* The new key */ 4439); 4440 4441/* 4442** Specify the activation key for a SEE database. Unless 4443** activated, none of the SEE routines will work. 4444*/ 4445void sqlite3_activate_see( 4446 const char *zPassPhrase /* Activation phrase */ 4447); 4448#endif 4449 4450#ifdef SQLITE_ENABLE_CEROD 4451/* 4452** Specify the activation key for a CEROD database. Unless 4453** activated, none of the CEROD routines will work. 4454*/ 4455void sqlite3_activate_cerod( 4456 const char *zPassPhrase /* Activation phrase */ 4457); 4458#endif 4459 4460/* 4461** CAPI3REF: Suspend Execution For A Short Time 4462** 4463** The sqlite3_sleep() function causes the current thread to suspend execution 4464** for at least a number of milliseconds specified in its parameter. 4465** 4466** If the operating system does not support sleep requests with 4467** millisecond time resolution, then the time will be rounded up to 4468** the nearest second. The number of milliseconds of sleep actually 4469** requested from the operating system is returned. 4470** 4471** ^SQLite implements this interface by calling the xSleep() 4472** method of the default [sqlite3_vfs] object. If the xSleep() method 4473** of the default VFS is not implemented correctly, or not implemented at 4474** all, then the behavior of sqlite3_sleep() may deviate from the description 4475** in the previous paragraphs. 4476*/ 4477int sqlite3_sleep(int); 4478 4479/* 4480** CAPI3REF: Name Of The Folder Holding Temporary Files 4481** 4482** ^(If this global variable is made to point to a string which is 4483** the name of a folder (a.k.a. directory), then all temporary files 4484** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4485** will be placed in that directory.)^ ^If this variable 4486** is a NULL pointer, then SQLite performs a search for an appropriate 4487** temporary file directory. 4488** 4489** It is not safe to read or modify this variable in more than one 4490** thread at a time. It is not safe to read or modify this variable 4491** if a [database connection] is being used at the same time in a separate 4492** thread. 4493** It is intended that this variable be set once 4494** as part of process initialization and before any SQLite interface 4495** routines have been called and that this variable remain unchanged 4496** thereafter. 4497** 4498** ^The [temp_store_directory pragma] may modify this variable and cause 4499** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4500** the [temp_store_directory pragma] always assumes that any string 4501** that this variable points to is held in memory obtained from 4502** [sqlite3_malloc] and the pragma may attempt to free that memory 4503** using [sqlite3_free]. 4504** Hence, if this variable is modified directly, either it should be 4505** made NULL or made to point to memory obtained from [sqlite3_malloc] 4506** or else the use of the [temp_store_directory pragma] should be avoided. 4507** 4508** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4509** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4510** features that require the use of temporary files may fail. Here is an 4511** example of how to do this using C++ with the Windows Runtime: 4512** 4513** <blockquote><pre> 4514** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4515** TemporaryFolder->Path->Data(); 4516** char zPathBuf[MAX_PATH + 1]; 4517** memset(zPathBuf, 0, sizeof(zPathBuf)); 4518** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4519** NULL, NULL); 4520** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4521** </pre></blockquote> 4522*/ 4523SQLITE_EXTERN char *sqlite3_temp_directory; 4524 4525/* 4526** CAPI3REF: Name Of The Folder Holding Database Files 4527** 4528** ^(If this global variable is made to point to a string which is 4529** the name of a folder (a.k.a. directory), then all database files 4530** specified with a relative pathname and created or accessed by 4531** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4532** to be relative to that directory.)^ ^If this variable is a NULL 4533** pointer, then SQLite assumes that all database files specified 4534** with a relative pathname are relative to the current directory 4535** for the process. Only the windows VFS makes use of this global 4536** variable; it is ignored by the unix VFS. 4537** 4538** Changing the value of this variable while a database connection is 4539** open can result in a corrupt database. 4540** 4541** It is not safe to read or modify this variable in more than one 4542** thread at a time. It is not safe to read or modify this variable 4543** if a [database connection] is being used at the same time in a separate 4544** thread. 4545** It is intended that this variable be set once 4546** as part of process initialization and before any SQLite interface 4547** routines have been called and that this variable remain unchanged 4548** thereafter. 4549** 4550** ^The [data_store_directory pragma] may modify this variable and cause 4551** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4552** the [data_store_directory pragma] always assumes that any string 4553** that this variable points to is held in memory obtained from 4554** [sqlite3_malloc] and the pragma may attempt to free that memory 4555** using [sqlite3_free]. 4556** Hence, if this variable is modified directly, either it should be 4557** made NULL or made to point to memory obtained from [sqlite3_malloc] 4558** or else the use of the [data_store_directory pragma] should be avoided. 4559*/ 4560SQLITE_EXTERN char *sqlite3_data_directory; 4561 4562/* 4563** CAPI3REF: Test For Auto-Commit Mode 4564** KEYWORDS: {autocommit mode} 4565** 4566** ^The sqlite3_get_autocommit() interface returns non-zero or 4567** zero if the given database connection is or is not in autocommit mode, 4568** respectively. ^Autocommit mode is on by default. 4569** ^Autocommit mode is disabled by a [BEGIN] statement. 4570** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4571** 4572** If certain kinds of errors occur on a statement within a multi-statement 4573** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4574** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4575** transaction might be rolled back automatically. The only way to 4576** find out whether SQLite automatically rolled back the transaction after 4577** an error is to use this function. 4578** 4579** If another thread changes the autocommit status of the database 4580** connection while this routine is running, then the return value 4581** is undefined. 4582*/ 4583int sqlite3_get_autocommit(sqlite3*); 4584 4585/* 4586** CAPI3REF: Find The Database Handle Of A Prepared Statement 4587** 4588** ^The sqlite3_db_handle interface returns the [database connection] handle 4589** to which a [prepared statement] belongs. ^The [database connection] 4590** returned by sqlite3_db_handle is the same [database connection] 4591** that was the first argument 4592** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4593** create the statement in the first place. 4594*/ 4595sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4596 4597/* 4598** CAPI3REF: Return The Filename For A Database Connection 4599** 4600** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4601** associated with database N of connection D. ^The main database file 4602** has the name "main". If there is no attached database N on the database 4603** connection D, or if database N is a temporary or in-memory database, then 4604** a NULL pointer is returned. 4605** 4606** ^The filename returned by this function is the output of the 4607** xFullPathname method of the [VFS]. ^In other words, the filename 4608** will be an absolute pathname, even if the filename used 4609** to open the database originally was a URI or relative pathname. 4610*/ 4611const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4612 4613/* 4614** CAPI3REF: Determine if a database is read-only 4615** 4616** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4617** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4618** the name of a database on connection D. 4619*/ 4620int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4621 4622/* 4623** CAPI3REF: Find the next prepared statement 4624** 4625** ^This interface returns a pointer to the next [prepared statement] after 4626** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4627** then this interface returns a pointer to the first prepared statement 4628** associated with the database connection pDb. ^If no prepared statement 4629** satisfies the conditions of this routine, it returns NULL. 4630** 4631** The [database connection] pointer D in a call to 4632** [sqlite3_next_stmt(D,S)] must refer to an open database 4633** connection and in particular must not be a NULL pointer. 4634*/ 4635sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4636 4637/* 4638** CAPI3REF: Commit And Rollback Notification Callbacks 4639** 4640** ^The sqlite3_commit_hook() interface registers a callback 4641** function to be invoked whenever a transaction is [COMMIT | committed]. 4642** ^Any callback set by a previous call to sqlite3_commit_hook() 4643** for the same database connection is overridden. 4644** ^The sqlite3_rollback_hook() interface registers a callback 4645** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4646** ^Any callback set by a previous call to sqlite3_rollback_hook() 4647** for the same database connection is overridden. 4648** ^The pArg argument is passed through to the callback. 4649** ^If the callback on a commit hook function returns non-zero, 4650** then the commit is converted into a rollback. 4651** 4652** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4653** return the P argument from the previous call of the same function 4654** on the same [database connection] D, or NULL for 4655** the first call for each function on D. 4656** 4657** The commit and rollback hook callbacks are not reentrant. 4658** The callback implementation must not do anything that will modify 4659** the database connection that invoked the callback. Any actions 4660** to modify the database connection must be deferred until after the 4661** completion of the [sqlite3_step()] call that triggered the commit 4662** or rollback hook in the first place. 4663** Note that running any other SQL statements, including SELECT statements, 4664** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4665** the database connections for the meaning of "modify" in this paragraph. 4666** 4667** ^Registering a NULL function disables the callback. 4668** 4669** ^When the commit hook callback routine returns zero, the [COMMIT] 4670** operation is allowed to continue normally. ^If the commit hook 4671** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4672** ^The rollback hook is invoked on a rollback that results from a commit 4673** hook returning non-zero, just as it would be with any other rollback. 4674** 4675** ^For the purposes of this API, a transaction is said to have been 4676** rolled back if an explicit "ROLLBACK" statement is executed, or 4677** an error or constraint causes an implicit rollback to occur. 4678** ^The rollback callback is not invoked if a transaction is 4679** automatically rolled back because the database connection is closed. 4680** 4681** See also the [sqlite3_update_hook()] interface. 4682*/ 4683void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4684void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4685 4686/* 4687** CAPI3REF: Data Change Notification Callbacks 4688** 4689** ^The sqlite3_update_hook() interface registers a callback function 4690** with the [database connection] identified by the first argument 4691** to be invoked whenever a row is updated, inserted or deleted. 4692** ^Any callback set by a previous call to this function 4693** for the same database connection is overridden. 4694** 4695** ^The second argument is a pointer to the function to invoke when a 4696** row is updated, inserted or deleted. 4697** ^The first argument to the callback is a copy of the third argument 4698** to sqlite3_update_hook(). 4699** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4700** or [SQLITE_UPDATE], depending on the operation that caused the callback 4701** to be invoked. 4702** ^The third and fourth arguments to the callback contain pointers to the 4703** database and table name containing the affected row. 4704** ^The final callback parameter is the [rowid] of the row. 4705** ^In the case of an update, this is the [rowid] after the update takes place. 4706** 4707** ^(The update hook is not invoked when internal system tables are 4708** modified (i.e. sqlite_master and sqlite_sequence).)^ 4709** 4710** ^In the current implementation, the update hook 4711** is not invoked when duplication rows are deleted because of an 4712** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4713** invoked when rows are deleted using the [truncate optimization]. 4714** The exceptions defined in this paragraph might change in a future 4715** release of SQLite. 4716** 4717** The update hook implementation must not do anything that will modify 4718** the database connection that invoked the update hook. Any actions 4719** to modify the database connection must be deferred until after the 4720** completion of the [sqlite3_step()] call that triggered the update hook. 4721** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4722** database connections for the meaning of "modify" in this paragraph. 4723** 4724** ^The sqlite3_update_hook(D,C,P) function 4725** returns the P argument from the previous call 4726** on the same [database connection] D, or NULL for 4727** the first call on D. 4728** 4729** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4730** interfaces. 4731*/ 4732void *sqlite3_update_hook( 4733 sqlite3*, 4734 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4735 void* 4736); 4737 4738/* 4739** CAPI3REF: Enable Or Disable Shared Pager Cache 4740** 4741** ^(This routine enables or disables the sharing of the database cache 4742** and schema data structures between [database connection | connections] 4743** to the same database. Sharing is enabled if the argument is true 4744** and disabled if the argument is false.)^ 4745** 4746** ^Cache sharing is enabled and disabled for an entire process. 4747** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4748** sharing was enabled or disabled for each thread separately. 4749** 4750** ^(The cache sharing mode set by this interface effects all subsequent 4751** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4752** Existing database connections continue use the sharing mode 4753** that was in effect at the time they were opened.)^ 4754** 4755** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4756** successfully. An [error code] is returned otherwise.)^ 4757** 4758** ^Shared cache is disabled by default. But this might change in 4759** future releases of SQLite. Applications that care about shared 4760** cache setting should set it explicitly. 4761** 4762** This interface is threadsafe on processors where writing a 4763** 32-bit integer is atomic. 4764** 4765** See Also: [SQLite Shared-Cache Mode] 4766*/ 4767int sqlite3_enable_shared_cache(int); 4768 4769/* 4770** CAPI3REF: Attempt To Free Heap Memory 4771** 4772** ^The sqlite3_release_memory() interface attempts to free N bytes 4773** of heap memory by deallocating non-essential memory allocations 4774** held by the database library. Memory used to cache database 4775** pages to improve performance is an example of non-essential memory. 4776** ^sqlite3_release_memory() returns the number of bytes actually freed, 4777** which might be more or less than the amount requested. 4778** ^The sqlite3_release_memory() routine is a no-op returning zero 4779** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4780** 4781** See also: [sqlite3_db_release_memory()] 4782*/ 4783int sqlite3_release_memory(int); 4784 4785/* 4786** CAPI3REF: Free Memory Used By A Database Connection 4787** 4788** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 4789** memory as possible from database connection D. Unlike the 4790** [sqlite3_release_memory()] interface, this interface is effect even 4791** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 4792** omitted. 4793** 4794** See also: [sqlite3_release_memory()] 4795*/ 4796int sqlite3_db_release_memory(sqlite3*); 4797 4798/* 4799** CAPI3REF: Impose A Limit On Heap Size 4800** 4801** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4802** soft limit on the amount of heap memory that may be allocated by SQLite. 4803** ^SQLite strives to keep heap memory utilization below the soft heap 4804** limit by reducing the number of pages held in the page cache 4805** as heap memory usages approaches the limit. 4806** ^The soft heap limit is "soft" because even though SQLite strives to stay 4807** below the limit, it will exceed the limit rather than generate 4808** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4809** is advisory only. 4810** 4811** ^The return value from sqlite3_soft_heap_limit64() is the size of 4812** the soft heap limit prior to the call, or negative in the case of an 4813** error. ^If the argument N is negative 4814** then no change is made to the soft heap limit. Hence, the current 4815** size of the soft heap limit can be determined by invoking 4816** sqlite3_soft_heap_limit64() with a negative argument. 4817** 4818** ^If the argument N is zero then the soft heap limit is disabled. 4819** 4820** ^(The soft heap limit is not enforced in the current implementation 4821** if one or more of following conditions are true: 4822** 4823** <ul> 4824** <li> The soft heap limit is set to zero. 4825** <li> Memory accounting is disabled using a combination of the 4826** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 4827** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 4828** <li> An alternative page cache implementation is specified using 4829** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 4830** <li> The page cache allocates from its own memory pool supplied 4831** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 4832** from the heap. 4833** </ul>)^ 4834** 4835** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 4836** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 4837** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 4838** the soft heap limit is enforced on every memory allocation. Without 4839** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 4840** when memory is allocated by the page cache. Testing suggests that because 4841** the page cache is the predominate memory user in SQLite, most 4842** applications will achieve adequate soft heap limit enforcement without 4843** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4844** 4845** The circumstances under which SQLite will enforce the soft heap limit may 4846** changes in future releases of SQLite. 4847*/ 4848sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 4849 4850/* 4851** CAPI3REF: Deprecated Soft Heap Limit Interface 4852** DEPRECATED 4853** 4854** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 4855** interface. This routine is provided for historical compatibility 4856** only. All new applications should use the 4857** [sqlite3_soft_heap_limit64()] interface rather than this one. 4858*/ 4859SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 4860 4861 4862/* 4863** CAPI3REF: Extract Metadata About A Column Of A Table 4864** 4865** ^This routine returns metadata about a specific column of a specific 4866** database table accessible using the [database connection] handle 4867** passed as the first function argument. 4868** 4869** ^The column is identified by the second, third and fourth parameters to 4870** this function. ^The second parameter is either the name of the database 4871** (i.e. "main", "temp", or an attached database) containing the specified 4872** table or NULL. ^If it is NULL, then all attached databases are searched 4873** for the table using the same algorithm used by the database engine to 4874** resolve unqualified table references. 4875** 4876** ^The third and fourth parameters to this function are the table and column 4877** name of the desired column, respectively. Neither of these parameters 4878** may be NULL. 4879** 4880** ^Metadata is returned by writing to the memory locations passed as the 5th 4881** and subsequent parameters to this function. ^Any of these arguments may be 4882** NULL, in which case the corresponding element of metadata is omitted. 4883** 4884** ^(<blockquote> 4885** <table border="1"> 4886** <tr><th> Parameter <th> Output<br>Type <th> Description 4887** 4888** <tr><td> 5th <td> const char* <td> Data type 4889** <tr><td> 6th <td> const char* <td> Name of default collation sequence 4890** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 4891** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 4892** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 4893** </table> 4894** </blockquote>)^ 4895** 4896** ^The memory pointed to by the character pointers returned for the 4897** declaration type and collation sequence is valid only until the next 4898** call to any SQLite API function. 4899** 4900** ^If the specified table is actually a view, an [error code] is returned. 4901** 4902** ^If the specified column is "rowid", "oid" or "_rowid_" and an 4903** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 4904** parameters are set for the explicitly declared column. ^(If there is no 4905** explicitly declared [INTEGER PRIMARY KEY] column, then the output 4906** parameters are set as follows: 4907** 4908** <pre> 4909** data type: "INTEGER" 4910** collation sequence: "BINARY" 4911** not null: 0 4912** primary key: 1 4913** auto increment: 0 4914** </pre>)^ 4915** 4916** ^(This function may load one or more schemas from database files. If an 4917** error occurs during this process, or if the requested table or column 4918** cannot be found, an [error code] is returned and an error message left 4919** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 4920** 4921** ^This API is only available if the library was compiled with the 4922** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 4923*/ 4924int sqlite3_table_column_metadata( 4925 sqlite3 *db, /* Connection handle */ 4926 const char *zDbName, /* Database name or NULL */ 4927 const char *zTableName, /* Table name */ 4928 const char *zColumnName, /* Column name */ 4929 char const **pzDataType, /* OUTPUT: Declared data type */ 4930 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4931 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4932 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4933 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4934); 4935 4936/* 4937** CAPI3REF: Load An Extension 4938** 4939** ^This interface loads an SQLite extension library from the named file. 4940** 4941** ^The sqlite3_load_extension() interface attempts to load an 4942** SQLite extension library contained in the file zFile. 4943** 4944** ^The entry point is zProc. 4945** ^zProc may be 0, in which case the name of the entry point 4946** defaults to "sqlite3_extension_init". 4947** ^The sqlite3_load_extension() interface returns 4948** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4949** ^If an error occurs and pzErrMsg is not 0, then the 4950** [sqlite3_load_extension()] interface shall attempt to 4951** fill *pzErrMsg with error message text stored in memory 4952** obtained from [sqlite3_malloc()]. The calling function 4953** should free this memory by calling [sqlite3_free()]. 4954** 4955** ^Extension loading must be enabled using 4956** [sqlite3_enable_load_extension()] prior to calling this API, 4957** otherwise an error will be returned. 4958** 4959** See also the [load_extension() SQL function]. 4960*/ 4961int sqlite3_load_extension( 4962 sqlite3 *db, /* Load the extension into this database connection */ 4963 const char *zFile, /* Name of the shared library containing extension */ 4964 const char *zProc, /* Entry point. Derived from zFile if 0 */ 4965 char **pzErrMsg /* Put error message here if not 0 */ 4966); 4967 4968/* 4969** CAPI3REF: Enable Or Disable Extension Loading 4970** 4971** ^So as not to open security holes in older applications that are 4972** unprepared to deal with extension loading, and as a means of disabling 4973** extension loading while evaluating user-entered SQL, the following API 4974** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 4975** 4976** ^Extension loading is off by default. See ticket #1863. 4977** ^Call the sqlite3_enable_load_extension() routine with onoff==1 4978** to turn extension loading on and call it with onoff==0 to turn 4979** it back off again. 4980*/ 4981int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4982 4983/* 4984** CAPI3REF: Automatically Load Statically Linked Extensions 4985** 4986** ^This interface causes the xEntryPoint() function to be invoked for 4987** each new [database connection] that is created. The idea here is that 4988** xEntryPoint() is the entry point for a statically linked SQLite extension 4989** that is to be automatically loaded into all new database connections. 4990** 4991** ^(Even though the function prototype shows that xEntryPoint() takes 4992** no arguments and returns void, SQLite invokes xEntryPoint() with three 4993** arguments and expects and integer result as if the signature of the 4994** entry point where as follows: 4995** 4996** <blockquote><pre> 4997** int xEntryPoint( 4998** sqlite3 *db, 4999** const char **pzErrMsg, 5000** const struct sqlite3_api_routines *pThunk 5001** ); 5002** </pre></blockquote>)^ 5003** 5004** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5005** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5006** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5007** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5008** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5009** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5010** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5011** 5012** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5013** on the list of automatic extensions is a harmless no-op. ^No entry point 5014** will be called more than once for each database connection that is opened. 5015** 5016** See also: [sqlite3_reset_auto_extension()]. 5017*/ 5018int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5019 5020/* 5021** CAPI3REF: Reset Automatic Extension Loading 5022** 5023** ^This interface disables all automatic extensions previously 5024** registered using [sqlite3_auto_extension()]. 5025*/ 5026void sqlite3_reset_auto_extension(void); 5027 5028/* 5029** The interface to the virtual-table mechanism is currently considered 5030** to be experimental. The interface might change in incompatible ways. 5031** If this is a problem for you, do not use the interface at this time. 5032** 5033** When the virtual-table mechanism stabilizes, we will declare the 5034** interface fixed, support it indefinitely, and remove this comment. 5035*/ 5036 5037/* 5038** Structures used by the virtual table interface 5039*/ 5040typedef struct sqlite3_vtab sqlite3_vtab; 5041typedef struct sqlite3_index_info sqlite3_index_info; 5042typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5043typedef struct sqlite3_module sqlite3_module; 5044 5045/* 5046** CAPI3REF: Virtual Table Object 5047** KEYWORDS: sqlite3_module {virtual table module} 5048** 5049** This structure, sometimes called a "virtual table module", 5050** defines the implementation of a [virtual tables]. 5051** This structure consists mostly of methods for the module. 5052** 5053** ^A virtual table module is created by filling in a persistent 5054** instance of this structure and passing a pointer to that instance 5055** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5056** ^The registration remains valid until it is replaced by a different 5057** module or until the [database connection] closes. The content 5058** of this structure must not change while it is registered with 5059** any database connection. 5060*/ 5061struct sqlite3_module { 5062 int iVersion; 5063 int (*xCreate)(sqlite3*, void *pAux, 5064 int argc, const char *const*argv, 5065 sqlite3_vtab **ppVTab, char**); 5066 int (*xConnect)(sqlite3*, void *pAux, 5067 int argc, const char *const*argv, 5068 sqlite3_vtab **ppVTab, char**); 5069 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5070 int (*xDisconnect)(sqlite3_vtab *pVTab); 5071 int (*xDestroy)(sqlite3_vtab *pVTab); 5072 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5073 int (*xClose)(sqlite3_vtab_cursor*); 5074 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5075 int argc, sqlite3_value **argv); 5076 int (*xNext)(sqlite3_vtab_cursor*); 5077 int (*xEof)(sqlite3_vtab_cursor*); 5078 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5079 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5080 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5081 int (*xBegin)(sqlite3_vtab *pVTab); 5082 int (*xSync)(sqlite3_vtab *pVTab); 5083 int (*xCommit)(sqlite3_vtab *pVTab); 5084 int (*xRollback)(sqlite3_vtab *pVTab); 5085 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5086 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5087 void **ppArg); 5088 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5089 /* The methods above are in version 1 of the sqlite_module object. Those 5090 ** below are for version 2 and greater. */ 5091 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5092 int (*xRelease)(sqlite3_vtab *pVTab, int); 5093 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5094}; 5095 5096/* 5097** CAPI3REF: Virtual Table Indexing Information 5098** KEYWORDS: sqlite3_index_info 5099** 5100** The sqlite3_index_info structure and its substructures is used as part 5101** of the [virtual table] interface to 5102** pass information into and receive the reply from the [xBestIndex] 5103** method of a [virtual table module]. The fields under **Inputs** are the 5104** inputs to xBestIndex and are read-only. xBestIndex inserts its 5105** results into the **Outputs** fields. 5106** 5107** ^(The aConstraint[] array records WHERE clause constraints of the form: 5108** 5109** <blockquote>column OP expr</blockquote> 5110** 5111** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5112** stored in aConstraint[].op using one of the 5113** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5114** ^(The index of the column is stored in 5115** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5116** expr on the right-hand side can be evaluated (and thus the constraint 5117** is usable) and false if it cannot.)^ 5118** 5119** ^The optimizer automatically inverts terms of the form "expr OP column" 5120** and makes other simplifications to the WHERE clause in an attempt to 5121** get as many WHERE clause terms into the form shown above as possible. 5122** ^The aConstraint[] array only reports WHERE clause terms that are 5123** relevant to the particular virtual table being queried. 5124** 5125** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5126** ^Each term of aOrderBy records a column of the ORDER BY clause. 5127** 5128** The [xBestIndex] method must fill aConstraintUsage[] with information 5129** about what parameters to pass to xFilter. ^If argvIndex>0 then 5130** the right-hand side of the corresponding aConstraint[] is evaluated 5131** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5132** is true, then the constraint is assumed to be fully handled by the 5133** virtual table and is not checked again by SQLite.)^ 5134** 5135** ^The idxNum and idxPtr values are recorded and passed into the 5136** [xFilter] method. 5137** ^[sqlite3_free()] is used to free idxPtr if and only if 5138** needToFreeIdxPtr is true. 5139** 5140** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5141** the correct order to satisfy the ORDER BY clause so that no separate 5142** sorting step is required. 5143** 5144** ^The estimatedCost value is an estimate of the cost of doing the 5145** particular lookup. A full scan of a table with N entries should have 5146** a cost of N. A binary search of a table of N entries should have a 5147** cost of approximately log(N). 5148*/ 5149struct sqlite3_index_info { 5150 /* Inputs */ 5151 int nConstraint; /* Number of entries in aConstraint */ 5152 struct sqlite3_index_constraint { 5153 int iColumn; /* Column on left-hand side of constraint */ 5154 unsigned char op; /* Constraint operator */ 5155 unsigned char usable; /* True if this constraint is usable */ 5156 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5157 } *aConstraint; /* Table of WHERE clause constraints */ 5158 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5159 struct sqlite3_index_orderby { 5160 int iColumn; /* Column number */ 5161 unsigned char desc; /* True for DESC. False for ASC. */ 5162 } *aOrderBy; /* The ORDER BY clause */ 5163 /* Outputs */ 5164 struct sqlite3_index_constraint_usage { 5165 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5166 unsigned char omit; /* Do not code a test for this constraint */ 5167 } *aConstraintUsage; 5168 int idxNum; /* Number used to identify the index */ 5169 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5170 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5171 int orderByConsumed; /* True if output is already ordered */ 5172 double estimatedCost; /* Estimated cost of using this index */ 5173}; 5174 5175/* 5176** CAPI3REF: Virtual Table Constraint Operator Codes 5177** 5178** These macros defined the allowed values for the 5179** [sqlite3_index_info].aConstraint[].op field. Each value represents 5180** an operator that is part of a constraint term in the wHERE clause of 5181** a query that uses a [virtual table]. 5182*/ 5183#define SQLITE_INDEX_CONSTRAINT_EQ 2 5184#define SQLITE_INDEX_CONSTRAINT_GT 4 5185#define SQLITE_INDEX_CONSTRAINT_LE 8 5186#define SQLITE_INDEX_CONSTRAINT_LT 16 5187#define SQLITE_INDEX_CONSTRAINT_GE 32 5188#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5189 5190/* 5191** CAPI3REF: Register A Virtual Table Implementation 5192** 5193** ^These routines are used to register a new [virtual table module] name. 5194** ^Module names must be registered before 5195** creating a new [virtual table] using the module and before using a 5196** preexisting [virtual table] for the module. 5197** 5198** ^The module name is registered on the [database connection] specified 5199** by the first parameter. ^The name of the module is given by the 5200** second parameter. ^The third parameter is a pointer to 5201** the implementation of the [virtual table module]. ^The fourth 5202** parameter is an arbitrary client data pointer that is passed through 5203** into the [xCreate] and [xConnect] methods of the virtual table module 5204** when a new virtual table is be being created or reinitialized. 5205** 5206** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5207** is a pointer to a destructor for the pClientData. ^SQLite will 5208** invoke the destructor function (if it is not NULL) when SQLite 5209** no longer needs the pClientData pointer. ^The destructor will also 5210** be invoked if the call to sqlite3_create_module_v2() fails. 5211** ^The sqlite3_create_module() 5212** interface is equivalent to sqlite3_create_module_v2() with a NULL 5213** destructor. 5214*/ 5215int sqlite3_create_module( 5216 sqlite3 *db, /* SQLite connection to register module with */ 5217 const char *zName, /* Name of the module */ 5218 const sqlite3_module *p, /* Methods for the module */ 5219 void *pClientData /* Client data for xCreate/xConnect */ 5220); 5221int sqlite3_create_module_v2( 5222 sqlite3 *db, /* SQLite connection to register module with */ 5223 const char *zName, /* Name of the module */ 5224 const sqlite3_module *p, /* Methods for the module */ 5225 void *pClientData, /* Client data for xCreate/xConnect */ 5226 void(*xDestroy)(void*) /* Module destructor function */ 5227); 5228 5229/* 5230** CAPI3REF: Virtual Table Instance Object 5231** KEYWORDS: sqlite3_vtab 5232** 5233** Every [virtual table module] implementation uses a subclass 5234** of this object to describe a particular instance 5235** of the [virtual table]. Each subclass will 5236** be tailored to the specific needs of the module implementation. 5237** The purpose of this superclass is to define certain fields that are 5238** common to all module implementations. 5239** 5240** ^Virtual tables methods can set an error message by assigning a 5241** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5242** take care that any prior string is freed by a call to [sqlite3_free()] 5243** prior to assigning a new string to zErrMsg. ^After the error message 5244** is delivered up to the client application, the string will be automatically 5245** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5246*/ 5247struct sqlite3_vtab { 5248 const sqlite3_module *pModule; /* The module for this virtual table */ 5249 int nRef; /* NO LONGER USED */ 5250 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5251 /* Virtual table implementations will typically add additional fields */ 5252}; 5253 5254/* 5255** CAPI3REF: Virtual Table Cursor Object 5256** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5257** 5258** Every [virtual table module] implementation uses a subclass of the 5259** following structure to describe cursors that point into the 5260** [virtual table] and are used 5261** to loop through the virtual table. Cursors are created using the 5262** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5263** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5264** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5265** of the module. Each module implementation will define 5266** the content of a cursor structure to suit its own needs. 5267** 5268** This superclass exists in order to define fields of the cursor that 5269** are common to all implementations. 5270*/ 5271struct sqlite3_vtab_cursor { 5272 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5273 /* Virtual table implementations will typically add additional fields */ 5274}; 5275 5276/* 5277** CAPI3REF: Declare The Schema Of A Virtual Table 5278** 5279** ^The [xCreate] and [xConnect] methods of a 5280** [virtual table module] call this interface 5281** to declare the format (the names and datatypes of the columns) of 5282** the virtual tables they implement. 5283*/ 5284int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5285 5286/* 5287** CAPI3REF: Overload A Function For A Virtual Table 5288** 5289** ^(Virtual tables can provide alternative implementations of functions 5290** using the [xFindFunction] method of the [virtual table module]. 5291** But global versions of those functions 5292** must exist in order to be overloaded.)^ 5293** 5294** ^(This API makes sure a global version of a function with a particular 5295** name and number of parameters exists. If no such function exists 5296** before this API is called, a new function is created.)^ ^The implementation 5297** of the new function always causes an exception to be thrown. So 5298** the new function is not good for anything by itself. Its only 5299** purpose is to be a placeholder function that can be overloaded 5300** by a [virtual table]. 5301*/ 5302int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5303 5304/* 5305** The interface to the virtual-table mechanism defined above (back up 5306** to a comment remarkably similar to this one) is currently considered 5307** to be experimental. The interface might change in incompatible ways. 5308** If this is a problem for you, do not use the interface at this time. 5309** 5310** When the virtual-table mechanism stabilizes, we will declare the 5311** interface fixed, support it indefinitely, and remove this comment. 5312*/ 5313 5314/* 5315** CAPI3REF: A Handle To An Open BLOB 5316** KEYWORDS: {BLOB handle} {BLOB handles} 5317** 5318** An instance of this object represents an open BLOB on which 5319** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5320** ^Objects of this type are created by [sqlite3_blob_open()] 5321** and destroyed by [sqlite3_blob_close()]. 5322** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5323** can be used to read or write small subsections of the BLOB. 5324** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5325*/ 5326typedef struct sqlite3_blob sqlite3_blob; 5327 5328/* 5329** CAPI3REF: Open A BLOB For Incremental I/O 5330** 5331** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5332** in row iRow, column zColumn, table zTable in database zDb; 5333** in other words, the same BLOB that would be selected by: 5334** 5335** <pre> 5336** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5337** </pre>)^ 5338** 5339** ^If the flags parameter is non-zero, then the BLOB is opened for read 5340** and write access. ^If it is zero, the BLOB is opened for read access. 5341** ^It is not possible to open a column that is part of an index or primary 5342** key for writing. ^If [foreign key constraints] are enabled, it is 5343** not possible to open a column that is part of a [child key] for writing. 5344** 5345** ^Note that the database name is not the filename that contains 5346** the database but rather the symbolic name of the database that 5347** appears after the AS keyword when the database is connected using [ATTACH]. 5348** ^For the main database file, the database name is "main". 5349** ^For TEMP tables, the database name is "temp". 5350** 5351** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5352** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5353** to be a null pointer.)^ 5354** ^This function sets the [database connection] error code and message 5355** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5356** functions. ^Note that the *ppBlob variable is always initialized in a 5357** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5358** regardless of the success or failure of this routine. 5359** 5360** ^(If the row that a BLOB handle points to is modified by an 5361** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5362** then the BLOB handle is marked as "expired". 5363** This is true if any column of the row is changed, even a column 5364** other than the one the BLOB handle is open on.)^ 5365** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5366** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5367** ^(Changes written into a BLOB prior to the BLOB expiring are not 5368** rolled back by the expiration of the BLOB. Such changes will eventually 5369** commit if the transaction continues to completion.)^ 5370** 5371** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5372** the opened blob. ^The size of a blob may not be changed by this 5373** interface. Use the [UPDATE] SQL command to change the size of a 5374** blob. 5375** 5376** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5377** and the built-in [zeroblob] SQL function can be used, if desired, 5378** to create an empty, zero-filled blob in which to read or write using 5379** this interface. 5380** 5381** To avoid a resource leak, every open [BLOB handle] should eventually 5382** be released by a call to [sqlite3_blob_close()]. 5383*/ 5384int sqlite3_blob_open( 5385 sqlite3*, 5386 const char *zDb, 5387 const char *zTable, 5388 const char *zColumn, 5389 sqlite3_int64 iRow, 5390 int flags, 5391 sqlite3_blob **ppBlob 5392); 5393 5394/* 5395** CAPI3REF: Move a BLOB Handle to a New Row 5396** 5397** ^This function is used to move an existing blob handle so that it points 5398** to a different row of the same database table. ^The new row is identified 5399** by the rowid value passed as the second argument. Only the row can be 5400** changed. ^The database, table and column on which the blob handle is open 5401** remain the same. Moving an existing blob handle to a new row can be 5402** faster than closing the existing handle and opening a new one. 5403** 5404** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5405** it must exist and there must be either a blob or text value stored in 5406** the nominated column.)^ ^If the new row is not present in the table, or if 5407** it does not contain a blob or text value, or if another error occurs, an 5408** SQLite error code is returned and the blob handle is considered aborted. 5409** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5410** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5411** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5412** always returns zero. 5413** 5414** ^This function sets the database handle error code and message. 5415*/ 5416SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5417 5418/* 5419** CAPI3REF: Close A BLOB Handle 5420** 5421** ^Closes an open [BLOB handle]. 5422** 5423** ^Closing a BLOB shall cause the current transaction to commit 5424** if there are no other BLOBs, no pending prepared statements, and the 5425** database connection is in [autocommit mode]. 5426** ^If any writes were made to the BLOB, they might be held in cache 5427** until the close operation if they will fit. 5428** 5429** ^(Closing the BLOB often forces the changes 5430** out to disk and so if any I/O errors occur, they will likely occur 5431** at the time when the BLOB is closed. Any errors that occur during 5432** closing are reported as a non-zero return value.)^ 5433** 5434** ^(The BLOB is closed unconditionally. Even if this routine returns 5435** an error code, the BLOB is still closed.)^ 5436** 5437** ^Calling this routine with a null pointer (such as would be returned 5438** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5439*/ 5440int sqlite3_blob_close(sqlite3_blob *); 5441 5442/* 5443** CAPI3REF: Return The Size Of An Open BLOB 5444** 5445** ^Returns the size in bytes of the BLOB accessible via the 5446** successfully opened [BLOB handle] in its only argument. ^The 5447** incremental blob I/O routines can only read or overwriting existing 5448** blob content; they cannot change the size of a blob. 5449** 5450** This routine only works on a [BLOB handle] which has been created 5451** by a prior successful call to [sqlite3_blob_open()] and which has not 5452** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5453** to this routine results in undefined and probably undesirable behavior. 5454*/ 5455int sqlite3_blob_bytes(sqlite3_blob *); 5456 5457/* 5458** CAPI3REF: Read Data From A BLOB Incrementally 5459** 5460** ^(This function is used to read data from an open [BLOB handle] into a 5461** caller-supplied buffer. N bytes of data are copied into buffer Z 5462** from the open BLOB, starting at offset iOffset.)^ 5463** 5464** ^If offset iOffset is less than N bytes from the end of the BLOB, 5465** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5466** less than zero, [SQLITE_ERROR] is returned and no data is read. 5467** ^The size of the blob (and hence the maximum value of N+iOffset) 5468** can be determined using the [sqlite3_blob_bytes()] interface. 5469** 5470** ^An attempt to read from an expired [BLOB handle] fails with an 5471** error code of [SQLITE_ABORT]. 5472** 5473** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5474** Otherwise, an [error code] or an [extended error code] is returned.)^ 5475** 5476** This routine only works on a [BLOB handle] which has been created 5477** by a prior successful call to [sqlite3_blob_open()] and which has not 5478** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5479** to this routine results in undefined and probably undesirable behavior. 5480** 5481** See also: [sqlite3_blob_write()]. 5482*/ 5483int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5484 5485/* 5486** CAPI3REF: Write Data Into A BLOB Incrementally 5487** 5488** ^This function is used to write data into an open [BLOB handle] from a 5489** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5490** into the open BLOB, starting at offset iOffset. 5491** 5492** ^If the [BLOB handle] passed as the first argument was not opened for 5493** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5494** this function returns [SQLITE_READONLY]. 5495** 5496** ^This function may only modify the contents of the BLOB; it is 5497** not possible to increase the size of a BLOB using this API. 5498** ^If offset iOffset is less than N bytes from the end of the BLOB, 5499** [SQLITE_ERROR] is returned and no data is written. ^If N is 5500** less than zero [SQLITE_ERROR] is returned and no data is written. 5501** The size of the BLOB (and hence the maximum value of N+iOffset) 5502** can be determined using the [sqlite3_blob_bytes()] interface. 5503** 5504** ^An attempt to write to an expired [BLOB handle] fails with an 5505** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5506** before the [BLOB handle] expired are not rolled back by the 5507** expiration of the handle, though of course those changes might 5508** have been overwritten by the statement that expired the BLOB handle 5509** or by other independent statements. 5510** 5511** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5512** Otherwise, an [error code] or an [extended error code] is returned.)^ 5513** 5514** This routine only works on a [BLOB handle] which has been created 5515** by a prior successful call to [sqlite3_blob_open()] and which has not 5516** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5517** to this routine results in undefined and probably undesirable behavior. 5518** 5519** See also: [sqlite3_blob_read()]. 5520*/ 5521int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5522 5523/* 5524** CAPI3REF: Virtual File System Objects 5525** 5526** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5527** that SQLite uses to interact 5528** with the underlying operating system. Most SQLite builds come with a 5529** single default VFS that is appropriate for the host computer. 5530** New VFSes can be registered and existing VFSes can be unregistered. 5531** The following interfaces are provided. 5532** 5533** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5534** ^Names are case sensitive. 5535** ^Names are zero-terminated UTF-8 strings. 5536** ^If there is no match, a NULL pointer is returned. 5537** ^If zVfsName is NULL then the default VFS is returned. 5538** 5539** ^New VFSes are registered with sqlite3_vfs_register(). 5540** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5541** ^The same VFS can be registered multiple times without injury. 5542** ^To make an existing VFS into the default VFS, register it again 5543** with the makeDflt flag set. If two different VFSes with the 5544** same name are registered, the behavior is undefined. If a 5545** VFS is registered with a name that is NULL or an empty string, 5546** then the behavior is undefined. 5547** 5548** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5549** ^(If the default VFS is unregistered, another VFS is chosen as 5550** the default. The choice for the new VFS is arbitrary.)^ 5551*/ 5552sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5553int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5554int sqlite3_vfs_unregister(sqlite3_vfs*); 5555 5556/* 5557** CAPI3REF: Mutexes 5558** 5559** The SQLite core uses these routines for thread 5560** synchronization. Though they are intended for internal 5561** use by SQLite, code that links against SQLite is 5562** permitted to use any of these routines. 5563** 5564** The SQLite source code contains multiple implementations 5565** of these mutex routines. An appropriate implementation 5566** is selected automatically at compile-time. ^(The following 5567** implementations are available in the SQLite core: 5568** 5569** <ul> 5570** <li> SQLITE_MUTEX_PTHREADS 5571** <li> SQLITE_MUTEX_W32 5572** <li> SQLITE_MUTEX_NOOP 5573** </ul>)^ 5574** 5575** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5576** that does no real locking and is appropriate for use in 5577** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and 5578** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5579** and Windows. 5580** 5581** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5582** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5583** implementation is included with the library. In this case the 5584** application must supply a custom mutex implementation using the 5585** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5586** before calling sqlite3_initialize() or any other public sqlite3_ 5587** function that calls sqlite3_initialize().)^ 5588** 5589** ^The sqlite3_mutex_alloc() routine allocates a new 5590** mutex and returns a pointer to it. ^If it returns NULL 5591** that means that a mutex could not be allocated. ^SQLite 5592** will unwind its stack and return an error. ^(The argument 5593** to sqlite3_mutex_alloc() is one of these integer constants: 5594** 5595** <ul> 5596** <li> SQLITE_MUTEX_FAST 5597** <li> SQLITE_MUTEX_RECURSIVE 5598** <li> SQLITE_MUTEX_STATIC_MASTER 5599** <li> SQLITE_MUTEX_STATIC_MEM 5600** <li> SQLITE_MUTEX_STATIC_MEM2 5601** <li> SQLITE_MUTEX_STATIC_PRNG 5602** <li> SQLITE_MUTEX_STATIC_LRU 5603** <li> SQLITE_MUTEX_STATIC_LRU2 5604** </ul>)^ 5605** 5606** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5607** cause sqlite3_mutex_alloc() to create 5608** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5609** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5610** The mutex implementation does not need to make a distinction 5611** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5612** not want to. ^SQLite will only request a recursive mutex in 5613** cases where it really needs one. ^If a faster non-recursive mutex 5614** implementation is available on the host platform, the mutex subsystem 5615** might return such a mutex in response to SQLITE_MUTEX_FAST. 5616** 5617** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5618** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5619** a pointer to a static preexisting mutex. ^Six static mutexes are 5620** used by the current version of SQLite. Future versions of SQLite 5621** may add additional static mutexes. Static mutexes are for internal 5622** use by SQLite only. Applications that use SQLite mutexes should 5623** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5624** SQLITE_MUTEX_RECURSIVE. 5625** 5626** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5627** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5628** returns a different mutex on every call. ^But for the static 5629** mutex types, the same mutex is returned on every call that has 5630** the same type number. 5631** 5632** ^The sqlite3_mutex_free() routine deallocates a previously 5633** allocated dynamic mutex. ^SQLite is careful to deallocate every 5634** dynamic mutex that it allocates. The dynamic mutexes must not be in 5635** use when they are deallocated. Attempting to deallocate a static 5636** mutex results in undefined behavior. ^SQLite never deallocates 5637** a static mutex. 5638** 5639** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5640** to enter a mutex. ^If another thread is already within the mutex, 5641** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5642** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5643** upon successful entry. ^(Mutexes created using 5644** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5645** In such cases the, 5646** mutex must be exited an equal number of times before another thread 5647** can enter.)^ ^(If the same thread tries to enter any other 5648** kind of mutex more than once, the behavior is undefined. 5649** SQLite will never exhibit 5650** such behavior in its own use of mutexes.)^ 5651** 5652** ^(Some systems (for example, Windows 95) do not support the operation 5653** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5654** will always return SQLITE_BUSY. The SQLite core only ever uses 5655** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5656** 5657** ^The sqlite3_mutex_leave() routine exits a mutex that was 5658** previously entered by the same thread. ^(The behavior 5659** is undefined if the mutex is not currently entered by the 5660** calling thread or is not currently allocated. SQLite will 5661** never do either.)^ 5662** 5663** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5664** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5665** behave as no-ops. 5666** 5667** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5668*/ 5669sqlite3_mutex *sqlite3_mutex_alloc(int); 5670void sqlite3_mutex_free(sqlite3_mutex*); 5671void sqlite3_mutex_enter(sqlite3_mutex*); 5672int sqlite3_mutex_try(sqlite3_mutex*); 5673void sqlite3_mutex_leave(sqlite3_mutex*); 5674 5675/* 5676** CAPI3REF: Mutex Methods Object 5677** 5678** An instance of this structure defines the low-level routines 5679** used to allocate and use mutexes. 5680** 5681** Usually, the default mutex implementations provided by SQLite are 5682** sufficient, however the user has the option of substituting a custom 5683** implementation for specialized deployments or systems for which SQLite 5684** does not provide a suitable implementation. In this case, the user 5685** creates and populates an instance of this structure to pass 5686** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5687** Additionally, an instance of this structure can be used as an 5688** output variable when querying the system for the current mutex 5689** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5690** 5691** ^The xMutexInit method defined by this structure is invoked as 5692** part of system initialization by the sqlite3_initialize() function. 5693** ^The xMutexInit routine is called by SQLite exactly once for each 5694** effective call to [sqlite3_initialize()]. 5695** 5696** ^The xMutexEnd method defined by this structure is invoked as 5697** part of system shutdown by the sqlite3_shutdown() function. The 5698** implementation of this method is expected to release all outstanding 5699** resources obtained by the mutex methods implementation, especially 5700** those obtained by the xMutexInit method. ^The xMutexEnd() 5701** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5702** 5703** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5704** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5705** xMutexNotheld) implement the following interfaces (respectively): 5706** 5707** <ul> 5708** <li> [sqlite3_mutex_alloc()] </li> 5709** <li> [sqlite3_mutex_free()] </li> 5710** <li> [sqlite3_mutex_enter()] </li> 5711** <li> [sqlite3_mutex_try()] </li> 5712** <li> [sqlite3_mutex_leave()] </li> 5713** <li> [sqlite3_mutex_held()] </li> 5714** <li> [sqlite3_mutex_notheld()] </li> 5715** </ul>)^ 5716** 5717** The only difference is that the public sqlite3_XXX functions enumerated 5718** above silently ignore any invocations that pass a NULL pointer instead 5719** of a valid mutex handle. The implementations of the methods defined 5720** by this structure are not required to handle this case, the results 5721** of passing a NULL pointer instead of a valid mutex handle are undefined 5722** (i.e. it is acceptable to provide an implementation that segfaults if 5723** it is passed a NULL pointer). 5724** 5725** The xMutexInit() method must be threadsafe. ^It must be harmless to 5726** invoke xMutexInit() multiple times within the same process and without 5727** intervening calls to xMutexEnd(). Second and subsequent calls to 5728** xMutexInit() must be no-ops. 5729** 5730** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5731** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5732** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5733** memory allocation for a fast or recursive mutex. 5734** 5735** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5736** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5737** If xMutexInit fails in any way, it is expected to clean up after itself 5738** prior to returning. 5739*/ 5740typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5741struct sqlite3_mutex_methods { 5742 int (*xMutexInit)(void); 5743 int (*xMutexEnd)(void); 5744 sqlite3_mutex *(*xMutexAlloc)(int); 5745 void (*xMutexFree)(sqlite3_mutex *); 5746 void (*xMutexEnter)(sqlite3_mutex *); 5747 int (*xMutexTry)(sqlite3_mutex *); 5748 void (*xMutexLeave)(sqlite3_mutex *); 5749 int (*xMutexHeld)(sqlite3_mutex *); 5750 int (*xMutexNotheld)(sqlite3_mutex *); 5751}; 5752 5753/* 5754** CAPI3REF: Mutex Verification Routines 5755** 5756** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5757** are intended for use inside assert() statements. ^The SQLite core 5758** never uses these routines except inside an assert() and applications 5759** are advised to follow the lead of the core. ^The SQLite core only 5760** provides implementations for these routines when it is compiled 5761** with the SQLITE_DEBUG flag. ^External mutex implementations 5762** are only required to provide these routines if SQLITE_DEBUG is 5763** defined and if NDEBUG is not defined. 5764** 5765** ^These routines should return true if the mutex in their argument 5766** is held or not held, respectively, by the calling thread. 5767** 5768** ^The implementation is not required to provide versions of these 5769** routines that actually work. If the implementation does not provide working 5770** versions of these routines, it should at least provide stubs that always 5771** return true so that one does not get spurious assertion failures. 5772** 5773** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5774** the routine should return 1. This seems counter-intuitive since 5775** clearly the mutex cannot be held if it does not exist. But 5776** the reason the mutex does not exist is because the build is not 5777** using mutexes. And we do not want the assert() containing the 5778** call to sqlite3_mutex_held() to fail, so a non-zero return is 5779** the appropriate thing to do. ^The sqlite3_mutex_notheld() 5780** interface should also return 1 when given a NULL pointer. 5781*/ 5782#ifndef NDEBUG 5783int sqlite3_mutex_held(sqlite3_mutex*); 5784int sqlite3_mutex_notheld(sqlite3_mutex*); 5785#endif 5786 5787/* 5788** CAPI3REF: Mutex Types 5789** 5790** The [sqlite3_mutex_alloc()] interface takes a single argument 5791** which is one of these integer constants. 5792** 5793** The set of static mutexes may change from one SQLite release to the 5794** next. Applications that override the built-in mutex logic must be 5795** prepared to accommodate additional static mutexes. 5796*/ 5797#define SQLITE_MUTEX_FAST 0 5798#define SQLITE_MUTEX_RECURSIVE 1 5799#define SQLITE_MUTEX_STATIC_MASTER 2 5800#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5801#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 5802#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 5803#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5804#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5805#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 5806#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 5807 5808/* 5809** CAPI3REF: Retrieve the mutex for a database connection 5810** 5811** ^This interface returns a pointer the [sqlite3_mutex] object that 5812** serializes access to the [database connection] given in the argument 5813** when the [threading mode] is Serialized. 5814** ^If the [threading mode] is Single-thread or Multi-thread then this 5815** routine returns a NULL pointer. 5816*/ 5817sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 5818 5819/* 5820** CAPI3REF: Low-Level Control Of Database Files 5821** 5822** ^The [sqlite3_file_control()] interface makes a direct call to the 5823** xFileControl method for the [sqlite3_io_methods] object associated 5824** with a particular database identified by the second argument. ^The 5825** name of the database is "main" for the main database or "temp" for the 5826** TEMP database, or the name that appears after the AS keyword for 5827** databases that are added using the [ATTACH] SQL command. 5828** ^A NULL pointer can be used in place of "main" to refer to the 5829** main database file. 5830** ^The third and fourth parameters to this routine 5831** are passed directly through to the second and third parameters of 5832** the xFileControl method. ^The return value of the xFileControl 5833** method becomes the return value of this routine. 5834** 5835** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 5836** a pointer to the underlying [sqlite3_file] object to be written into 5837** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 5838** case is a short-circuit path which does not actually invoke the 5839** underlying sqlite3_io_methods.xFileControl method. 5840** 5841** ^If the second parameter (zDbName) does not match the name of any 5842** open database file, then SQLITE_ERROR is returned. ^This error 5843** code is not remembered and will not be recalled by [sqlite3_errcode()] 5844** or [sqlite3_errmsg()]. The underlying xFileControl method might 5845** also return SQLITE_ERROR. There is no way to distinguish between 5846** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5847** xFileControl method. 5848** 5849** See also: [SQLITE_FCNTL_LOCKSTATE] 5850*/ 5851int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5852 5853/* 5854** CAPI3REF: Testing Interface 5855** 5856** ^The sqlite3_test_control() interface is used to read out internal 5857** state of SQLite and to inject faults into SQLite for testing 5858** purposes. ^The first parameter is an operation code that determines 5859** the number, meaning, and operation of all subsequent parameters. 5860** 5861** This interface is not for use by applications. It exists solely 5862** for verifying the correct operation of the SQLite library. Depending 5863** on how the SQLite library is compiled, this interface might not exist. 5864** 5865** The details of the operation codes, their meanings, the parameters 5866** they take, and what they do are all subject to change without notice. 5867** Unlike most of the SQLite API, this function is not guaranteed to 5868** operate consistently from one release to the next. 5869*/ 5870int sqlite3_test_control(int op, ...); 5871 5872/* 5873** CAPI3REF: Testing Interface Operation Codes 5874** 5875** These constants are the valid operation code parameters used 5876** as the first argument to [sqlite3_test_control()]. 5877** 5878** These parameters and their meanings are subject to change 5879** without notice. These values are for testing purposes only. 5880** Applications should not use any of these parameters or the 5881** [sqlite3_test_control()] interface. 5882*/ 5883#define SQLITE_TESTCTRL_FIRST 5 5884#define SQLITE_TESTCTRL_PRNG_SAVE 5 5885#define SQLITE_TESTCTRL_PRNG_RESTORE 6 5886#define SQLITE_TESTCTRL_PRNG_RESET 7 5887#define SQLITE_TESTCTRL_BITVEC_TEST 8 5888#define SQLITE_TESTCTRL_FAULT_INSTALL 9 5889#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 5890#define SQLITE_TESTCTRL_PENDING_BYTE 11 5891#define SQLITE_TESTCTRL_ASSERT 12 5892#define SQLITE_TESTCTRL_ALWAYS 13 5893#define SQLITE_TESTCTRL_RESERVE 14 5894#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 5895#define SQLITE_TESTCTRL_ISKEYWORD 16 5896#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 5897#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 5898#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 5899#define SQLITE_TESTCTRL_LAST 19 5900 5901/* 5902** CAPI3REF: SQLite Runtime Status 5903** 5904** ^This interface is used to retrieve runtime status information 5905** about the performance of SQLite, and optionally to reset various 5906** highwater marks. ^The first argument is an integer code for 5907** the specific parameter to measure. ^(Recognized integer codes 5908** are of the form [status parameters | SQLITE_STATUS_...].)^ 5909** ^The current value of the parameter is returned into *pCurrent. 5910** ^The highest recorded value is returned in *pHighwater. ^If the 5911** resetFlag is true, then the highest record value is reset after 5912** *pHighwater is written. ^(Some parameters do not record the highest 5913** value. For those parameters 5914** nothing is written into *pHighwater and the resetFlag is ignored.)^ 5915** ^(Other parameters record only the highwater mark and not the current 5916** value. For these latter parameters nothing is written into *pCurrent.)^ 5917** 5918** ^The sqlite3_status() routine returns SQLITE_OK on success and a 5919** non-zero [error code] on failure. 5920** 5921** This routine is threadsafe but is not atomic. This routine can be 5922** called while other threads are running the same or different SQLite 5923** interfaces. However the values returned in *pCurrent and 5924** *pHighwater reflect the status of SQLite at different points in time 5925** and it is possible that another thread might change the parameter 5926** in between the times when *pCurrent and *pHighwater are written. 5927** 5928** See also: [sqlite3_db_status()] 5929*/ 5930int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 5931 5932 5933/* 5934** CAPI3REF: Status Parameters 5935** KEYWORDS: {status parameters} 5936** 5937** These integer constants designate various run-time status parameters 5938** that can be returned by [sqlite3_status()]. 5939** 5940** <dl> 5941** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 5942** <dd>This parameter is the current amount of memory checked out 5943** using [sqlite3_malloc()], either directly or indirectly. The 5944** figure includes calls made to [sqlite3_malloc()] by the application 5945** and internal memory usage by the SQLite library. Scratch memory 5946** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 5947** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 5948** this parameter. The amount returned is the sum of the allocation 5949** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 5950** 5951** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 5952** <dd>This parameter records the largest memory allocation request 5953** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 5954** internal equivalents). Only the value returned in the 5955** *pHighwater parameter to [sqlite3_status()] is of interest. 5956** The value written into the *pCurrent parameter is undefined.</dd>)^ 5957** 5958** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 5959** <dd>This parameter records the number of separate memory allocations 5960** currently checked out.</dd>)^ 5961** 5962** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 5963** <dd>This parameter returns the number of pages used out of the 5964** [pagecache memory allocator] that was configured using 5965** [SQLITE_CONFIG_PAGECACHE]. The 5966** value returned is in pages, not in bytes.</dd>)^ 5967** 5968** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 5969** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 5970** <dd>This parameter returns the number of bytes of page cache 5971** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 5972** buffer and where forced to overflow to [sqlite3_malloc()]. The 5973** returned value includes allocations that overflowed because they 5974** where too large (they were larger than the "sz" parameter to 5975** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 5976** no space was left in the page cache.</dd>)^ 5977** 5978** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 5979** <dd>This parameter records the largest memory allocation request 5980** handed to [pagecache memory allocator]. Only the value returned in the 5981** *pHighwater parameter to [sqlite3_status()] is of interest. 5982** The value written into the *pCurrent parameter is undefined.</dd>)^ 5983** 5984** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 5985** <dd>This parameter returns the number of allocations used out of the 5986** [scratch memory allocator] configured using 5987** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 5988** in bytes. Since a single thread may only have one scratch allocation 5989** outstanding at time, this parameter also reports the number of threads 5990** using scratch memory at the same time.</dd>)^ 5991** 5992** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 5993** <dd>This parameter returns the number of bytes of scratch memory 5994** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 5995** buffer and where forced to overflow to [sqlite3_malloc()]. The values 5996** returned include overflows because the requested allocation was too 5997** larger (that is, because the requested allocation was larger than the 5998** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 5999** slots were available. 6000** </dd>)^ 6001** 6002** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6003** <dd>This parameter records the largest memory allocation request 6004** handed to [scratch memory allocator]. Only the value returned in the 6005** *pHighwater parameter to [sqlite3_status()] is of interest. 6006** The value written into the *pCurrent parameter is undefined.</dd>)^ 6007** 6008** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6009** <dd>This parameter records the deepest parser stack. It is only 6010** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6011** </dl> 6012** 6013** New status parameters may be added from time to time. 6014*/ 6015#define SQLITE_STATUS_MEMORY_USED 0 6016#define SQLITE_STATUS_PAGECACHE_USED 1 6017#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6018#define SQLITE_STATUS_SCRATCH_USED 3 6019#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6020#define SQLITE_STATUS_MALLOC_SIZE 5 6021#define SQLITE_STATUS_PARSER_STACK 6 6022#define SQLITE_STATUS_PAGECACHE_SIZE 7 6023#define SQLITE_STATUS_SCRATCH_SIZE 8 6024#define SQLITE_STATUS_MALLOC_COUNT 9 6025 6026/* 6027** CAPI3REF: Database Connection Status 6028** 6029** ^This interface is used to retrieve runtime status information 6030** about a single [database connection]. ^The first argument is the 6031** database connection object to be interrogated. ^The second argument 6032** is an integer constant, taken from the set of 6033** [SQLITE_DBSTATUS options], that 6034** determines the parameter to interrogate. The set of 6035** [SQLITE_DBSTATUS options] is likely 6036** to grow in future releases of SQLite. 6037** 6038** ^The current value of the requested parameter is written into *pCur 6039** and the highest instantaneous value is written into *pHiwtr. ^If 6040** the resetFlg is true, then the highest instantaneous value is 6041** reset back down to the current value. 6042** 6043** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6044** non-zero [error code] on failure. 6045** 6046** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6047*/ 6048int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6049 6050/* 6051** CAPI3REF: Status Parameters for database connections 6052** KEYWORDS: {SQLITE_DBSTATUS options} 6053** 6054** These constants are the available integer "verbs" that can be passed as 6055** the second argument to the [sqlite3_db_status()] interface. 6056** 6057** New verbs may be added in future releases of SQLite. Existing verbs 6058** might be discontinued. Applications should check the return code from 6059** [sqlite3_db_status()] to make sure that the call worked. 6060** The [sqlite3_db_status()] interface will return a non-zero error code 6061** if a discontinued or unsupported verb is invoked. 6062** 6063** <dl> 6064** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6065** <dd>This parameter returns the number of lookaside memory slots currently 6066** checked out.</dd>)^ 6067** 6068** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6069** <dd>This parameter returns the number malloc attempts that were 6070** satisfied using lookaside memory. Only the high-water value is meaningful; 6071** the current value is always zero.)^ 6072** 6073** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6074** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6075** <dd>This parameter returns the number malloc attempts that might have 6076** been satisfied using lookaside memory but failed due to the amount of 6077** memory requested being larger than the lookaside slot size. 6078** Only the high-water value is meaningful; 6079** the current value is always zero.)^ 6080** 6081** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6082** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6083** <dd>This parameter returns the number malloc attempts that might have 6084** been satisfied using lookaside memory but failed due to all lookaside 6085** memory already being in use. 6086** Only the high-water value is meaningful; 6087** the current value is always zero.)^ 6088** 6089** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6090** <dd>This parameter returns the approximate number of of bytes of heap 6091** memory used by all pager caches associated with the database connection.)^ 6092** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6093** 6094** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6095** <dd>This parameter returns the approximate number of of bytes of heap 6096** memory used to store the schema for all databases associated 6097** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6098** ^The full amount of memory used by the schemas is reported, even if the 6099** schema memory is shared with other database connections due to 6100** [shared cache mode] being enabled. 6101** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6102** 6103** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6104** <dd>This parameter returns the approximate number of of bytes of heap 6105** and lookaside memory used by all prepared statements associated with 6106** the database connection.)^ 6107** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6108** </dd> 6109** 6110** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6111** <dd>This parameter returns the number of pager cache hits that have 6112** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6113** is always 0. 6114** </dd> 6115** 6116** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6117** <dd>This parameter returns the number of pager cache misses that have 6118** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6119** is always 0. 6120** </dd> 6121** 6122** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6123** <dd>This parameter returns the number of dirty cache entries that have 6124** been written to disk. Specifically, the number of pages written to the 6125** wal file in wal mode databases, or the number of pages written to the 6126** database file in rollback mode databases. Any pages written as part of 6127** transaction rollback or database recovery operations are not included. 6128** If an IO or other error occurs while writing a page to disk, the effect 6129** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6130** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6131** </dd> 6132** </dl> 6133*/ 6134#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6135#define SQLITE_DBSTATUS_CACHE_USED 1 6136#define SQLITE_DBSTATUS_SCHEMA_USED 2 6137#define SQLITE_DBSTATUS_STMT_USED 3 6138#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6139#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6140#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6141#define SQLITE_DBSTATUS_CACHE_HIT 7 6142#define SQLITE_DBSTATUS_CACHE_MISS 8 6143#define SQLITE_DBSTATUS_CACHE_WRITE 9 6144#define SQLITE_DBSTATUS_MAX 9 /* Largest defined DBSTATUS */ 6145 6146 6147/* 6148** CAPI3REF: Prepared Statement Status 6149** 6150** ^(Each prepared statement maintains various 6151** [SQLITE_STMTSTATUS counters] that measure the number 6152** of times it has performed specific operations.)^ These counters can 6153** be used to monitor the performance characteristics of the prepared 6154** statements. For example, if the number of table steps greatly exceeds 6155** the number of table searches or result rows, that would tend to indicate 6156** that the prepared statement is using a full table scan rather than 6157** an index. 6158** 6159** ^(This interface is used to retrieve and reset counter values from 6160** a [prepared statement]. The first argument is the prepared statement 6161** object to be interrogated. The second argument 6162** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6163** to be interrogated.)^ 6164** ^The current value of the requested counter is returned. 6165** ^If the resetFlg is true, then the counter is reset to zero after this 6166** interface call returns. 6167** 6168** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6169*/ 6170int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6171 6172/* 6173** CAPI3REF: Status Parameters for prepared statements 6174** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6175** 6176** These preprocessor macros define integer codes that name counter 6177** values associated with the [sqlite3_stmt_status()] interface. 6178** The meanings of the various counters are as follows: 6179** 6180** <dl> 6181** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6182** <dd>^This is the number of times that SQLite has stepped forward in 6183** a table as part of a full table scan. Large numbers for this counter 6184** may indicate opportunities for performance improvement through 6185** careful use of indices.</dd> 6186** 6187** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6188** <dd>^This is the number of sort operations that have occurred. 6189** A non-zero value in this counter may indicate an opportunity to 6190** improvement performance through careful use of indices.</dd> 6191** 6192** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6193** <dd>^This is the number of rows inserted into transient indices that 6194** were created automatically in order to help joins run faster. 6195** A non-zero value in this counter may indicate an opportunity to 6196** improvement performance by adding permanent indices that do not 6197** need to be reinitialized each time the statement is run.</dd> 6198** </dl> 6199*/ 6200#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6201#define SQLITE_STMTSTATUS_SORT 2 6202#define SQLITE_STMTSTATUS_AUTOINDEX 3 6203 6204/* 6205** CAPI3REF: Custom Page Cache Object 6206** 6207** The sqlite3_pcache type is opaque. It is implemented by 6208** the pluggable module. The SQLite core has no knowledge of 6209** its size or internal structure and never deals with the 6210** sqlite3_pcache object except by holding and passing pointers 6211** to the object. 6212** 6213** See [sqlite3_pcache_methods2] for additional information. 6214*/ 6215typedef struct sqlite3_pcache sqlite3_pcache; 6216 6217/* 6218** CAPI3REF: Custom Page Cache Object 6219** 6220** The sqlite3_pcache_page object represents a single page in the 6221** page cache. The page cache will allocate instances of this 6222** object. Various methods of the page cache use pointers to instances 6223** of this object as parameters or as their return value. 6224** 6225** See [sqlite3_pcache_methods2] for additional information. 6226*/ 6227typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6228struct sqlite3_pcache_page { 6229 void *pBuf; /* The content of the page */ 6230 void *pExtra; /* Extra information associated with the page */ 6231}; 6232 6233/* 6234** CAPI3REF: Application Defined Page Cache. 6235** KEYWORDS: {page cache} 6236** 6237** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6238** register an alternative page cache implementation by passing in an 6239** instance of the sqlite3_pcache_methods2 structure.)^ 6240** In many applications, most of the heap memory allocated by 6241** SQLite is used for the page cache. 6242** By implementing a 6243** custom page cache using this API, an application can better control 6244** the amount of memory consumed by SQLite, the way in which 6245** that memory is allocated and released, and the policies used to 6246** determine exactly which parts of a database file are cached and for 6247** how long. 6248** 6249** The alternative page cache mechanism is an 6250** extreme measure that is only needed by the most demanding applications. 6251** The built-in page cache is recommended for most uses. 6252** 6253** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6254** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6255** the application may discard the parameter after the call to 6256** [sqlite3_config()] returns.)^ 6257** 6258** [[the xInit() page cache method]] 6259** ^(The xInit() method is called once for each effective 6260** call to [sqlite3_initialize()])^ 6261** (usually only once during the lifetime of the process). ^(The xInit() 6262** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6263** The intent of the xInit() method is to set up global data structures 6264** required by the custom page cache implementation. 6265** ^(If the xInit() method is NULL, then the 6266** built-in default page cache is used instead of the application defined 6267** page cache.)^ 6268** 6269** [[the xShutdown() page cache method]] 6270** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6271** It can be used to clean up 6272** any outstanding resources before process shutdown, if required. 6273** ^The xShutdown() method may be NULL. 6274** 6275** ^SQLite automatically serializes calls to the xInit method, 6276** so the xInit method need not be threadsafe. ^The 6277** xShutdown method is only called from [sqlite3_shutdown()] so it does 6278** not need to be threadsafe either. All other methods must be threadsafe 6279** in multithreaded applications. 6280** 6281** ^SQLite will never invoke xInit() more than once without an intervening 6282** call to xShutdown(). 6283** 6284** [[the xCreate() page cache methods]] 6285** ^SQLite invokes the xCreate() method to construct a new cache instance. 6286** SQLite will typically create one cache instance for each open database file, 6287** though this is not guaranteed. ^The 6288** first parameter, szPage, is the size in bytes of the pages that must 6289** be allocated by the cache. ^szPage will always a power of two. ^The 6290** second parameter szExtra is a number of bytes of extra storage 6291** associated with each page cache entry. ^The szExtra parameter will 6292** a number less than 250. SQLite will use the 6293** extra szExtra bytes on each page to store metadata about the underlying 6294** database page on disk. The value passed into szExtra depends 6295** on the SQLite version, the target platform, and how SQLite was compiled. 6296** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6297** created will be used to cache database pages of a file stored on disk, or 6298** false if it is used for an in-memory database. The cache implementation 6299** does not have to do anything special based with the value of bPurgeable; 6300** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6301** never invoke xUnpin() except to deliberately delete a page. 6302** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6303** false will always have the "discard" flag set to true. 6304** ^Hence, a cache created with bPurgeable false will 6305** never contain any unpinned pages. 6306** 6307** [[the xCachesize() page cache method]] 6308** ^(The xCachesize() method may be called at any time by SQLite to set the 6309** suggested maximum cache-size (number of pages stored by) the cache 6310** instance passed as the first argument. This is the value configured using 6311** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6312** parameter, the implementation is not required to do anything with this 6313** value; it is advisory only. 6314** 6315** [[the xPagecount() page cache methods]] 6316** The xPagecount() method must return the number of pages currently 6317** stored in the cache, both pinned and unpinned. 6318** 6319** [[the xFetch() page cache methods]] 6320** The xFetch() method locates a page in the cache and returns a pointer to 6321** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6322** The pBuf element of the returned sqlite3_pcache_page object will be a 6323** pointer to a buffer of szPage bytes used to store the content of a 6324** single database page. The pExtra element of sqlite3_pcache_page will be 6325** a pointer to the szExtra bytes of extra storage that SQLite has requested 6326** for each entry in the page cache. 6327** 6328** The page to be fetched is determined by the key. ^The minimum key value 6329** is 1. After it has been retrieved using xFetch, the page is considered 6330** to be "pinned". 6331** 6332** If the requested page is already in the page cache, then the page cache 6333** implementation must return a pointer to the page buffer with its content 6334** intact. If the requested page is not already in the cache, then the 6335** cache implementation should use the value of the createFlag 6336** parameter to help it determined what action to take: 6337** 6338** <table border=1 width=85% align=center> 6339** <tr><th> createFlag <th> Behaviour when page is not already in cache 6340** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6341** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6342** Otherwise return NULL. 6343** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6344** NULL if allocating a new page is effectively impossible. 6345** </table> 6346** 6347** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6348** will only use a createFlag of 2 after a prior call with a createFlag of 1 6349** failed.)^ In between the to xFetch() calls, SQLite may 6350** attempt to unpin one or more cache pages by spilling the content of 6351** pinned pages to disk and synching the operating system disk cache. 6352** 6353** [[the xUnpin() page cache method]] 6354** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6355** as its second argument. If the third parameter, discard, is non-zero, 6356** then the page must be evicted from the cache. 6357** ^If the discard parameter is 6358** zero, then the page may be discarded or retained at the discretion of 6359** page cache implementation. ^The page cache implementation 6360** may choose to evict unpinned pages at any time. 6361** 6362** The cache must not perform any reference counting. A single 6363** call to xUnpin() unpins the page regardless of the number of prior calls 6364** to xFetch(). 6365** 6366** [[the xRekey() page cache methods]] 6367** The xRekey() method is used to change the key value associated with the 6368** page passed as the second argument. If the cache 6369** previously contains an entry associated with newKey, it must be 6370** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6371** to be pinned. 6372** 6373** When SQLite calls the xTruncate() method, the cache must discard all 6374** existing cache entries with page numbers (keys) greater than or equal 6375** to the value of the iLimit parameter passed to xTruncate(). If any 6376** of these pages are pinned, they are implicitly unpinned, meaning that 6377** they can be safely discarded. 6378** 6379** [[the xDestroy() page cache method]] 6380** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6381** All resources associated with the specified cache should be freed. ^After 6382** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6383** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6384** functions. 6385** 6386** [[the xShrink() page cache method]] 6387** ^SQLite invokes the xShrink() method when it wants the page cache to 6388** free up as much of heap memory as possible. The page cache implementation 6389** is not obligated to free any memory, but well-behaved implementations should 6390** do their best. 6391*/ 6392typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6393struct sqlite3_pcache_methods2 { 6394 int iVersion; 6395 void *pArg; 6396 int (*xInit)(void*); 6397 void (*xShutdown)(void*); 6398 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6399 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6400 int (*xPagecount)(sqlite3_pcache*); 6401 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6402 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6403 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6404 unsigned oldKey, unsigned newKey); 6405 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6406 void (*xDestroy)(sqlite3_pcache*); 6407 void (*xShrink)(sqlite3_pcache*); 6408}; 6409 6410/* 6411** This is the obsolete pcache_methods object that has now been replaced 6412** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6413** retained in the header file for backwards compatibility only. 6414*/ 6415typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6416struct sqlite3_pcache_methods { 6417 void *pArg; 6418 int (*xInit)(void*); 6419 void (*xShutdown)(void*); 6420 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6421 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6422 int (*xPagecount)(sqlite3_pcache*); 6423 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6424 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6425 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6426 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6427 void (*xDestroy)(sqlite3_pcache*); 6428}; 6429 6430 6431/* 6432** CAPI3REF: Online Backup Object 6433** 6434** The sqlite3_backup object records state information about an ongoing 6435** online backup operation. ^The sqlite3_backup object is created by 6436** a call to [sqlite3_backup_init()] and is destroyed by a call to 6437** [sqlite3_backup_finish()]. 6438** 6439** See Also: [Using the SQLite Online Backup API] 6440*/ 6441typedef struct sqlite3_backup sqlite3_backup; 6442 6443/* 6444** CAPI3REF: Online Backup API. 6445** 6446** The backup API copies the content of one database into another. 6447** It is useful either for creating backups of databases or 6448** for copying in-memory databases to or from persistent files. 6449** 6450** See Also: [Using the SQLite Online Backup API] 6451** 6452** ^SQLite holds a write transaction open on the destination database file 6453** for the duration of the backup operation. 6454** ^The source database is read-locked only while it is being read; 6455** it is not locked continuously for the entire backup operation. 6456** ^Thus, the backup may be performed on a live source database without 6457** preventing other database connections from 6458** reading or writing to the source database while the backup is underway. 6459** 6460** ^(To perform a backup operation: 6461** <ol> 6462** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6463** backup, 6464** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6465** the data between the two databases, and finally 6466** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6467** associated with the backup operation. 6468** </ol>)^ 6469** There should be exactly one call to sqlite3_backup_finish() for each 6470** successful call to sqlite3_backup_init(). 6471** 6472** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6473** 6474** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6475** [database connection] associated with the destination database 6476** and the database name, respectively. 6477** ^The database name is "main" for the main database, "temp" for the 6478** temporary database, or the name specified after the AS keyword in 6479** an [ATTACH] statement for an attached database. 6480** ^The S and M arguments passed to 6481** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6482** and database name of the source database, respectively. 6483** ^The source and destination [database connections] (parameters S and D) 6484** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6485** an error. 6486** 6487** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6488** returned and an error code and error message are stored in the 6489** destination [database connection] D. 6490** ^The error code and message for the failed call to sqlite3_backup_init() 6491** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6492** [sqlite3_errmsg16()] functions. 6493** ^A successful call to sqlite3_backup_init() returns a pointer to an 6494** [sqlite3_backup] object. 6495** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6496** sqlite3_backup_finish() functions to perform the specified backup 6497** operation. 6498** 6499** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6500** 6501** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6502** the source and destination databases specified by [sqlite3_backup] object B. 6503** ^If N is negative, all remaining source pages are copied. 6504** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6505** are still more pages to be copied, then the function returns [SQLITE_OK]. 6506** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6507** from source to destination, then it returns [SQLITE_DONE]. 6508** ^If an error occurs while running sqlite3_backup_step(B,N), 6509** then an [error code] is returned. ^As well as [SQLITE_OK] and 6510** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6511** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6512** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6513** 6514** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6515** <ol> 6516** <li> the destination database was opened read-only, or 6517** <li> the destination database is using write-ahead-log journaling 6518** and the destination and source page sizes differ, or 6519** <li> the destination database is an in-memory database and the 6520** destination and source page sizes differ. 6521** </ol>)^ 6522** 6523** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6524** the [sqlite3_busy_handler | busy-handler function] 6525** is invoked (if one is specified). ^If the 6526** busy-handler returns non-zero before the lock is available, then 6527** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6528** sqlite3_backup_step() can be retried later. ^If the source 6529** [database connection] 6530** is being used to write to the source database when sqlite3_backup_step() 6531** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6532** case the call to sqlite3_backup_step() can be retried later on. ^(If 6533** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6534** [SQLITE_READONLY] is returned, then 6535** there is no point in retrying the call to sqlite3_backup_step(). These 6536** errors are considered fatal.)^ The application must accept 6537** that the backup operation has failed and pass the backup operation handle 6538** to the sqlite3_backup_finish() to release associated resources. 6539** 6540** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6541** on the destination file. ^The exclusive lock is not released until either 6542** sqlite3_backup_finish() is called or the backup operation is complete 6543** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6544** sqlite3_backup_step() obtains a [shared lock] on the source database that 6545** lasts for the duration of the sqlite3_backup_step() call. 6546** ^Because the source database is not locked between calls to 6547** sqlite3_backup_step(), the source database may be modified mid-way 6548** through the backup process. ^If the source database is modified by an 6549** external process or via a database connection other than the one being 6550** used by the backup operation, then the backup will be automatically 6551** restarted by the next call to sqlite3_backup_step(). ^If the source 6552** database is modified by the using the same database connection as is used 6553** by the backup operation, then the backup database is automatically 6554** updated at the same time. 6555** 6556** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6557** 6558** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6559** application wishes to abandon the backup operation, the application 6560** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6561** ^The sqlite3_backup_finish() interfaces releases all 6562** resources associated with the [sqlite3_backup] object. 6563** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6564** active write-transaction on the destination database is rolled back. 6565** The [sqlite3_backup] object is invalid 6566** and may not be used following a call to sqlite3_backup_finish(). 6567** 6568** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6569** sqlite3_backup_step() errors occurred, regardless or whether or not 6570** sqlite3_backup_step() completed. 6571** ^If an out-of-memory condition or IO error occurred during any prior 6572** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6573** sqlite3_backup_finish() returns the corresponding [error code]. 6574** 6575** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6576** is not a permanent error and does not affect the return value of 6577** sqlite3_backup_finish(). 6578** 6579** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6580** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6581** 6582** ^Each call to sqlite3_backup_step() sets two values inside 6583** the [sqlite3_backup] object: the number of pages still to be backed 6584** up and the total number of pages in the source database file. 6585** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6586** retrieve these two values, respectively. 6587** 6588** ^The values returned by these functions are only updated by 6589** sqlite3_backup_step(). ^If the source database is modified during a backup 6590** operation, then the values are not updated to account for any extra 6591** pages that need to be updated or the size of the source database file 6592** changing. 6593** 6594** <b>Concurrent Usage of Database Handles</b> 6595** 6596** ^The source [database connection] may be used by the application for other 6597** purposes while a backup operation is underway or being initialized. 6598** ^If SQLite is compiled and configured to support threadsafe database 6599** connections, then the source database connection may be used concurrently 6600** from within other threads. 6601** 6602** However, the application must guarantee that the destination 6603** [database connection] is not passed to any other API (by any thread) after 6604** sqlite3_backup_init() is called and before the corresponding call to 6605** sqlite3_backup_finish(). SQLite does not currently check to see 6606** if the application incorrectly accesses the destination [database connection] 6607** and so no error code is reported, but the operations may malfunction 6608** nevertheless. Use of the destination database connection while a 6609** backup is in progress might also also cause a mutex deadlock. 6610** 6611** If running in [shared cache mode], the application must 6612** guarantee that the shared cache used by the destination database 6613** is not accessed while the backup is running. In practice this means 6614** that the application must guarantee that the disk file being 6615** backed up to is not accessed by any connection within the process, 6616** not just the specific connection that was passed to sqlite3_backup_init(). 6617** 6618** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6619** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6620** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6621** APIs are not strictly speaking threadsafe. If they are invoked at the 6622** same time as another thread is invoking sqlite3_backup_step() it is 6623** possible that they return invalid values. 6624*/ 6625sqlite3_backup *sqlite3_backup_init( 6626 sqlite3 *pDest, /* Destination database handle */ 6627 const char *zDestName, /* Destination database name */ 6628 sqlite3 *pSource, /* Source database handle */ 6629 const char *zSourceName /* Source database name */ 6630); 6631int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6632int sqlite3_backup_finish(sqlite3_backup *p); 6633int sqlite3_backup_remaining(sqlite3_backup *p); 6634int sqlite3_backup_pagecount(sqlite3_backup *p); 6635 6636/* 6637** CAPI3REF: Unlock Notification 6638** 6639** ^When running in shared-cache mode, a database operation may fail with 6640** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6641** individual tables within the shared-cache cannot be obtained. See 6642** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6643** ^This API may be used to register a callback that SQLite will invoke 6644** when the connection currently holding the required lock relinquishes it. 6645** ^This API is only available if the library was compiled with the 6646** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6647** 6648** See Also: [Using the SQLite Unlock Notification Feature]. 6649** 6650** ^Shared-cache locks are released when a database connection concludes 6651** its current transaction, either by committing it or rolling it back. 6652** 6653** ^When a connection (known as the blocked connection) fails to obtain a 6654** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6655** identity of the database connection (the blocking connection) that 6656** has locked the required resource is stored internally. ^After an 6657** application receives an SQLITE_LOCKED error, it may call the 6658** sqlite3_unlock_notify() method with the blocked connection handle as 6659** the first argument to register for a callback that will be invoked 6660** when the blocking connections current transaction is concluded. ^The 6661** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6662** call that concludes the blocking connections transaction. 6663** 6664** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6665** there is a chance that the blocking connection will have already 6666** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6667** If this happens, then the specified callback is invoked immediately, 6668** from within the call to sqlite3_unlock_notify().)^ 6669** 6670** ^If the blocked connection is attempting to obtain a write-lock on a 6671** shared-cache table, and more than one other connection currently holds 6672** a read-lock on the same table, then SQLite arbitrarily selects one of 6673** the other connections to use as the blocking connection. 6674** 6675** ^(There may be at most one unlock-notify callback registered by a 6676** blocked connection. If sqlite3_unlock_notify() is called when the 6677** blocked connection already has a registered unlock-notify callback, 6678** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6679** called with a NULL pointer as its second argument, then any existing 6680** unlock-notify callback is canceled. ^The blocked connections 6681** unlock-notify callback may also be canceled by closing the blocked 6682** connection using [sqlite3_close()]. 6683** 6684** The unlock-notify callback is not reentrant. If an application invokes 6685** any sqlite3_xxx API functions from within an unlock-notify callback, a 6686** crash or deadlock may be the result. 6687** 6688** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6689** returns SQLITE_OK. 6690** 6691** <b>Callback Invocation Details</b> 6692** 6693** When an unlock-notify callback is registered, the application provides a 6694** single void* pointer that is passed to the callback when it is invoked. 6695** However, the signature of the callback function allows SQLite to pass 6696** it an array of void* context pointers. The first argument passed to 6697** an unlock-notify callback is a pointer to an array of void* pointers, 6698** and the second is the number of entries in the array. 6699** 6700** When a blocking connections transaction is concluded, there may be 6701** more than one blocked connection that has registered for an unlock-notify 6702** callback. ^If two or more such blocked connections have specified the 6703** same callback function, then instead of invoking the callback function 6704** multiple times, it is invoked once with the set of void* context pointers 6705** specified by the blocked connections bundled together into an array. 6706** This gives the application an opportunity to prioritize any actions 6707** related to the set of unblocked database connections. 6708** 6709** <b>Deadlock Detection</b> 6710** 6711** Assuming that after registering for an unlock-notify callback a 6712** database waits for the callback to be issued before taking any further 6713** action (a reasonable assumption), then using this API may cause the 6714** application to deadlock. For example, if connection X is waiting for 6715** connection Y's transaction to be concluded, and similarly connection 6716** Y is waiting on connection X's transaction, then neither connection 6717** will proceed and the system may remain deadlocked indefinitely. 6718** 6719** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6720** detection. ^If a given call to sqlite3_unlock_notify() would put the 6721** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6722** unlock-notify callback is registered. The system is said to be in 6723** a deadlocked state if connection A has registered for an unlock-notify 6724** callback on the conclusion of connection B's transaction, and connection 6725** B has itself registered for an unlock-notify callback when connection 6726** A's transaction is concluded. ^Indirect deadlock is also detected, so 6727** the system is also considered to be deadlocked if connection B has 6728** registered for an unlock-notify callback on the conclusion of connection 6729** C's transaction, where connection C is waiting on connection A. ^Any 6730** number of levels of indirection are allowed. 6731** 6732** <b>The "DROP TABLE" Exception</b> 6733** 6734** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6735** always appropriate to call sqlite3_unlock_notify(). There is however, 6736** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6737** SQLite checks if there are any currently executing SELECT statements 6738** that belong to the same connection. If there are, SQLITE_LOCKED is 6739** returned. In this case there is no "blocking connection", so invoking 6740** sqlite3_unlock_notify() results in the unlock-notify callback being 6741** invoked immediately. If the application then re-attempts the "DROP TABLE" 6742** or "DROP INDEX" query, an infinite loop might be the result. 6743** 6744** One way around this problem is to check the extended error code returned 6745** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6746** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6747** the special "DROP TABLE/INDEX" case, the extended error code is just 6748** SQLITE_LOCKED.)^ 6749*/ 6750int sqlite3_unlock_notify( 6751 sqlite3 *pBlocked, /* Waiting connection */ 6752 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6753 void *pNotifyArg /* Argument to pass to xNotify */ 6754); 6755 6756 6757/* 6758** CAPI3REF: String Comparison 6759** 6760** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 6761** and extensions to compare the contents of two buffers containing UTF-8 6762** strings in a case-independent fashion, using the same definition of "case 6763** independence" that SQLite uses internally when comparing identifiers. 6764*/ 6765int sqlite3_stricmp(const char *, const char *); 6766int sqlite3_strnicmp(const char *, const char *, int); 6767 6768/* 6769** CAPI3REF: Error Logging Interface 6770** 6771** ^The [sqlite3_log()] interface writes a message into the error log 6772** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 6773** ^If logging is enabled, the zFormat string and subsequent arguments are 6774** used with [sqlite3_snprintf()] to generate the final output string. 6775** 6776** The sqlite3_log() interface is intended for use by extensions such as 6777** virtual tables, collating functions, and SQL functions. While there is 6778** nothing to prevent an application from calling sqlite3_log(), doing so 6779** is considered bad form. 6780** 6781** The zFormat string must not be NULL. 6782** 6783** To avoid deadlocks and other threading problems, the sqlite3_log() routine 6784** will not use dynamically allocated memory. The log message is stored in 6785** a fixed-length buffer on the stack. If the log message is longer than 6786** a few hundred characters, it will be truncated to the length of the 6787** buffer. 6788*/ 6789void sqlite3_log(int iErrCode, const char *zFormat, ...); 6790 6791/* 6792** CAPI3REF: Write-Ahead Log Commit Hook 6793** 6794** ^The [sqlite3_wal_hook()] function is used to register a callback that 6795** will be invoked each time a database connection commits data to a 6796** [write-ahead log] (i.e. whenever a transaction is committed in 6797** [journal_mode | journal_mode=WAL mode]). 6798** 6799** ^The callback is invoked by SQLite after the commit has taken place and 6800** the associated write-lock on the database released, so the implementation 6801** may read, write or [checkpoint] the database as required. 6802** 6803** ^The first parameter passed to the callback function when it is invoked 6804** is a copy of the third parameter passed to sqlite3_wal_hook() when 6805** registering the callback. ^The second is a copy of the database handle. 6806** ^The third parameter is the name of the database that was written to - 6807** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 6808** is the number of pages currently in the write-ahead log file, 6809** including those that were just committed. 6810** 6811** The callback function should normally return [SQLITE_OK]. ^If an error 6812** code is returned, that error will propagate back up through the 6813** SQLite code base to cause the statement that provoked the callback 6814** to report an error, though the commit will have still occurred. If the 6815** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 6816** that does not correspond to any valid SQLite error code, the results 6817** are undefined. 6818** 6819** A single database handle may have at most a single write-ahead log callback 6820** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 6821** previously registered write-ahead log callback. ^Note that the 6822** [sqlite3_wal_autocheckpoint()] interface and the 6823** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 6824** those overwrite any prior [sqlite3_wal_hook()] settings. 6825*/ 6826void *sqlite3_wal_hook( 6827 sqlite3*, 6828 int(*)(void *,sqlite3*,const char*,int), 6829 void* 6830); 6831 6832/* 6833** CAPI3REF: Configure an auto-checkpoint 6834** 6835** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 6836** [sqlite3_wal_hook()] that causes any database on [database connection] D 6837** to automatically [checkpoint] 6838** after committing a transaction if there are N or 6839** more frames in the [write-ahead log] file. ^Passing zero or 6840** a negative value as the nFrame parameter disables automatic 6841** checkpoints entirely. 6842** 6843** ^The callback registered by this function replaces any existing callback 6844** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 6845** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 6846** configured by this function. 6847** 6848** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 6849** from SQL. 6850** 6851** ^Every new [database connection] defaults to having the auto-checkpoint 6852** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 6853** pages. The use of this interface 6854** is only necessary if the default setting is found to be suboptimal 6855** for a particular application. 6856*/ 6857int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 6858 6859/* 6860** CAPI3REF: Checkpoint a database 6861** 6862** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 6863** on [database connection] D to be [checkpointed]. ^If X is NULL or an 6864** empty string, then a checkpoint is run on all databases of 6865** connection D. ^If the database connection D is not in 6866** [WAL | write-ahead log mode] then this interface is a harmless no-op. 6867** 6868** ^The [wal_checkpoint pragma] can be used to invoke this interface 6869** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 6870** [wal_autocheckpoint pragma] can be used to cause this interface to be 6871** run whenever the WAL reaches a certain size threshold. 6872** 6873** See also: [sqlite3_wal_checkpoint_v2()] 6874*/ 6875int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 6876 6877/* 6878** CAPI3REF: Checkpoint a database 6879** 6880** Run a checkpoint operation on WAL database zDb attached to database 6881** handle db. The specific operation is determined by the value of the 6882** eMode parameter: 6883** 6884** <dl> 6885** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 6886** Checkpoint as many frames as possible without waiting for any database 6887** readers or writers to finish. Sync the db file if all frames in the log 6888** are checkpointed. This mode is the same as calling 6889** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 6890** 6891** <dt>SQLITE_CHECKPOINT_FULL<dd> 6892** This mode blocks (calls the busy-handler callback) until there is no 6893** database writer and all readers are reading from the most recent database 6894** snapshot. It then checkpoints all frames in the log file and syncs the 6895** database file. This call blocks database writers while it is running, 6896** but not database readers. 6897** 6898** <dt>SQLITE_CHECKPOINT_RESTART<dd> 6899** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 6900** checkpointing the log file it blocks (calls the busy-handler callback) 6901** until all readers are reading from the database file only. This ensures 6902** that the next client to write to the database file restarts the log file 6903** from the beginning. This call blocks database writers while it is running, 6904** but not database readers. 6905** </dl> 6906** 6907** If pnLog is not NULL, then *pnLog is set to the total number of frames in 6908** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 6909** the total number of checkpointed frames (including any that were already 6910** checkpointed when this function is called). *pnLog and *pnCkpt may be 6911** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 6912** If no values are available because of an error, they are both set to -1 6913** before returning to communicate this to the caller. 6914** 6915** All calls obtain an exclusive "checkpoint" lock on the database file. If 6916** any other process is running a checkpoint operation at the same time, the 6917** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 6918** busy-handler configured, it will not be invoked in this case. 6919** 6920** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 6921** "writer" lock on the database file. If the writer lock cannot be obtained 6922** immediately, and a busy-handler is configured, it is invoked and the writer 6923** lock retried until either the busy-handler returns 0 or the lock is 6924** successfully obtained. The busy-handler is also invoked while waiting for 6925** database readers as described above. If the busy-handler returns 0 before 6926** the writer lock is obtained or while waiting for database readers, the 6927** checkpoint operation proceeds from that point in the same way as 6928** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 6929** without blocking any further. SQLITE_BUSY is returned in this case. 6930** 6931** If parameter zDb is NULL or points to a zero length string, then the 6932** specified operation is attempted on all WAL databases. In this case the 6933** values written to output parameters *pnLog and *pnCkpt are undefined. If 6934** an SQLITE_BUSY error is encountered when processing one or more of the 6935** attached WAL databases, the operation is still attempted on any remaining 6936** attached databases and SQLITE_BUSY is returned to the caller. If any other 6937** error occurs while processing an attached database, processing is abandoned 6938** and the error code returned to the caller immediately. If no error 6939** (SQLITE_BUSY or otherwise) is encountered while processing the attached 6940** databases, SQLITE_OK is returned. 6941** 6942** If database zDb is the name of an attached database that is not in WAL 6943** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 6944** zDb is not NULL (or a zero length string) and is not the name of any 6945** attached database, SQLITE_ERROR is returned to the caller. 6946*/ 6947int sqlite3_wal_checkpoint_v2( 6948 sqlite3 *db, /* Database handle */ 6949 const char *zDb, /* Name of attached database (or NULL) */ 6950 int eMode, /* SQLITE_CHECKPOINT_* value */ 6951 int *pnLog, /* OUT: Size of WAL log in frames */ 6952 int *pnCkpt /* OUT: Total number of frames checkpointed */ 6953); 6954 6955/* 6956** CAPI3REF: Checkpoint operation parameters 6957** 6958** These constants can be used as the 3rd parameter to 6959** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 6960** documentation for additional information about the meaning and use of 6961** each of these values. 6962*/ 6963#define SQLITE_CHECKPOINT_PASSIVE 0 6964#define SQLITE_CHECKPOINT_FULL 1 6965#define SQLITE_CHECKPOINT_RESTART 2 6966 6967/* 6968** CAPI3REF: Virtual Table Interface Configuration 6969** 6970** This function may be called by either the [xConnect] or [xCreate] method 6971** of a [virtual table] implementation to configure 6972** various facets of the virtual table interface. 6973** 6974** If this interface is invoked outside the context of an xConnect or 6975** xCreate virtual table method then the behavior is undefined. 6976** 6977** At present, there is only one option that may be configured using 6978** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 6979** may be added in the future. 6980*/ 6981int sqlite3_vtab_config(sqlite3*, int op, ...); 6982 6983/* 6984** CAPI3REF: Virtual Table Configuration Options 6985** 6986** These macros define the various options to the 6987** [sqlite3_vtab_config()] interface that [virtual table] implementations 6988** can use to customize and optimize their behavior. 6989** 6990** <dl> 6991** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 6992** <dd>Calls of the form 6993** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 6994** where X is an integer. If X is zero, then the [virtual table] whose 6995** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 6996** support constraints. In this configuration (which is the default) if 6997** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 6998** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 6999** specified as part of the users SQL statement, regardless of the actual 7000** ON CONFLICT mode specified. 7001** 7002** If X is non-zero, then the virtual table implementation guarantees 7003** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7004** any modifications to internal or persistent data structures have been made. 7005** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7006** is able to roll back a statement or database transaction, and abandon 7007** or continue processing the current SQL statement as appropriate. 7008** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7009** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7010** had been ABORT. 7011** 7012** Virtual table implementations that are required to handle OR REPLACE 7013** must do so within the [xUpdate] method. If a call to the 7014** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7015** CONFLICT policy is REPLACE, the virtual table implementation should 7016** silently replace the appropriate rows within the xUpdate callback and 7017** return SQLITE_OK. Or, if this is not possible, it may return 7018** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7019** constraint handling. 7020** </dl> 7021*/ 7022#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7023 7024/* 7025** CAPI3REF: Determine The Virtual Table Conflict Policy 7026** 7027** This function may only be called from within a call to the [xUpdate] method 7028** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7029** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7030** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7031** of the SQL statement that triggered the call to the [xUpdate] method of the 7032** [virtual table]. 7033*/ 7034int sqlite3_vtab_on_conflict(sqlite3 *); 7035 7036/* 7037** CAPI3REF: Conflict resolution modes 7038** 7039** These constants are returned by [sqlite3_vtab_on_conflict()] to 7040** inform a [virtual table] implementation what the [ON CONFLICT] mode 7041** is for the SQL statement being evaluated. 7042** 7043** Note that the [SQLITE_IGNORE] constant is also used as a potential 7044** return value from the [sqlite3_set_authorizer()] callback and that 7045** [SQLITE_ABORT] is also a [result code]. 7046*/ 7047#define SQLITE_ROLLBACK 1 7048/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7049#define SQLITE_FAIL 3 7050/* #define SQLITE_ABORT 4 // Also an error code */ 7051#define SQLITE_REPLACE 5 7052 7053 7054 7055/* 7056** Undo the hack that converts floating point types to integer for 7057** builds on processors without floating point support. 7058*/ 7059#ifdef SQLITE_OMIT_FLOATING_POINT 7060# undef double 7061#endif 7062 7063#ifdef __cplusplus 7064} /* End of the 'extern "C"' block */ 7065#endif 7066#endif 7067