sqlite3.h

嵌入式数据系统软件！

** One can use this text in an SQL statement as follows:
**
** <blockquote><pre>
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
**  sqlite3_exec(db, zSQL, 0, 0, 0);
**  sqlite3_free(zSQL);
** </pre></blockquote>
**
** Because the %q format string is used, the '\'' character in zText
** is escaped and the SQL generated is as follows:
**
** <blockquote><pre>
**  INSERT INTO table1 VALUES('It''s a happy day!')
** </pre></blockquote>
**
** This is correct.  Had we used %s instead of %q, the generated SQL
** would have looked like this:
**
** <blockquote><pre>
**  INSERT INTO table1 VALUES('It's a happy day!');
** </pre></blockquote>
**
** This second example is an SQL syntax error.  As a general rule you
** should always use %q instead of %s when inserting text into a string 
** literal.
**
** {F17411} The %Q option works like %q except it also adds single quotes around
** the outside of the total string.  Or if the parameter in the argument
** list is a NULL pointer, %Q substitutes the text "NULL" (without single
** quotes) in place of the %Q option. {END}  So, for example, one could say:
**
** <blockquote><pre>
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
**  sqlite3_exec(db, zSQL, 0, 0, 0);
**  sqlite3_free(zSQL);
** </pre></blockquote>
**
** The code above will render a correct SQL statement in the zSQL
** variable even if the zText variable is a NULL pointer.
**
** {F17412} The "%z" formatting option works exactly like "%s" with the
** addition that after the string has been read and copied into
** the result, [sqlite3_free()] is called on the input string. {END}
*/
char *sqlite3_mprintf(const char*,...);
char *sqlite3_vmprintf(const char*, va_list);
char *sqlite3_snprintf(int,char*,const char*, ...);

/*
** CAPI3REF: Memory Allocation Subsystem {F17300}
**
** {F17301} The SQLite core  uses these three routines for all of its own
** internal memory allocation needs. {END}  "Core" in the previous sentence
** does not include operating-system specific VFS implementation.  The
** windows VFS uses native malloc and free for some operations.
**
** {F17302} The sqlite3_malloc() routine returns a pointer to a block
** of memory at least N bytes in length, where N is the parameter.
** {F17303} If sqlite3_malloc() is unable to obtain sufficient free
** memory, it returns a NULL pointer.  {F17304} If the parameter N to
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
** a NULL pointer.
**
** {F17305} Calling sqlite3_free() with a pointer previously returned
** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
** that it might be reused.  {F17306} The sqlite3_free() routine is
** a no-op if is called with a NULL pointer.  Passing a NULL pointer
** to sqlite3_free() is harmless.  {U17307} After being freed, memory
** should neither be read nor written.  Even reading previously freed
** memory might result in a segmentation fault or other severe error.
** {U17309} Memory corruption, a segmentation fault, or other severe error
** might result if sqlite3_free() is called with a non-NULL pointer that
** was not obtained from sqlite3_malloc() or sqlite3_free().
**
** {F17310} The sqlite3_realloc() interface attempts to resize a
** prior memory allocation to be at least N bytes, where N is the
** second parameter.  The memory allocation to be resized is the first
** parameter.  {F17311} If the first parameter to sqlite3_realloc()
** is a NULL pointer then its behavior is identical to calling
** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
** {F17312} If the second parameter to sqlite3_realloc() is zero or
** negative then the behavior is exactly the same as calling
** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
** {F17313} Sqlite3_realloc() returns a pointer to a memory allocation
** of at least N bytes in size or NULL if sufficient memory is unavailable.
** {F17314} If M is the size of the prior allocation, then min(N,M) bytes
** of the prior allocation are copied into the beginning of buffer returned
** by sqlite3_realloc() and the prior allocation is freed.
** {F17315} If sqlite3_realloc() returns NULL, then the prior allocation
** is not freed.
**
** {F17316} The memory returned by sqlite3_malloc() and sqlite3_realloc()
** is always aligned to at least an 8 byte boundary. {END}
**
** {F17381} The default implementation
** of the memory allocation subsystem uses the malloc(), realloc()
** and free() provided by the standard C library. {F17382} However, if 
** SQLite is compiled with the following C preprocessor macro
**
** <blockquote> SQLITE_MEMORY_SIZE=<i>NNN</i> </blockquote>
**
** where <i>NNN</i> is an integer, then SQLite create a static
** array of at least <i>NNN</i> bytes in size and use that array
** for all of its dynamic memory allocation needs. {END}  Additional
** memory allocator options may be added in future releases.
**
** In SQLite version 3.5.0 and 3.5.1, it was possible to define
** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
** implementation of these routines to be omitted.  That capability
** is no longer provided.  Only built-in memory allocators can be
** used.
**
** The windows OS interface layer calls
** the system malloc() and free() directly when converting
** filenames between the UTF-8 encoding used by SQLite
** and whatever filename encoding is used by the particular windows
** installation.  Memory allocation errors are detected, but
** they are reported back as [SQLITE_CANTOPEN] or
** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
*/
void *sqlite3_malloc(int);
void *sqlite3_realloc(void*, int);
void sqlite3_free(void*);

/*
** CAPI3REF: Memory Allocator Statistics {F17370}
**
** In addition to the basic three allocation routines 
** [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()],
** the memory allocation subsystem included with the SQLite
** sources provides the interfaces shown here.
**
** {F17371} The sqlite3_memory_used() routine returns the
** number of bytes of memory currently outstanding (malloced but not freed).
** {F17372} The value returned by sqlite3_memory_used() includes
** any overhead added by SQLite, but not overhead added by the
** library malloc() that backs the sqlite3_malloc() implementation.
** {F17373} The sqlite3_memory_highwater() routines returns the
** maximum number of bytes that have been outstanding at any time
** since the highwater mark was last reset.
** {F17374} The byte count returned by sqlite3_memory_highwater()
** uses the same byte counting rules as sqlite3_memory_used(). {END}
** In other words, overhead added internally by SQLite is counted,
** but overhead from the underlying system malloc is not.
** {F17375} If the parameter to sqlite3_memory_highwater() is true,
** then the highwater mark is reset to the current value of
** sqlite3_memory_used() and the prior highwater mark (before the
** reset) is returned.  {F17376}  If the parameter to 
** sqlite3_memory_highwater() is zero, then the highwater mark is
** unchanged.
*/
sqlite3_int64 sqlite3_memory_used(void);
sqlite3_int64 sqlite3_memory_highwater(int resetFlag);

/*
** CAPI3REF: Compile-Time Authorization Callbacks {F12500}
**
** {F12501} This routine registers a authorizer callback with a particular
** database connection, supplied in the first argument. {F12502}
** The authorizer callback is invoked as SQL statements are being compiled
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  {F12503} At various
** points during the compilation process, as logic is being created
** to perform various actions, the authorizer callback is invoked to
** see if those actions are allowed.  The authorizer callback should
** return SQLITE_OK to allow the action, [SQLITE_IGNORE] to disallow the
** specific action but allow the SQL statement to continue to be
** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
** rejected with an error.  {F12504} If the authorizer callback returns
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
** then [sqlite3_prepare_v2()] or equivalent call that triggered
** the authorizer shall
** fail with an SQLITE_ERROR error code and an appropriate error message. {END}
**
** When the callback returns [SQLITE_OK], that means the operation
** requested is ok.  {F12505} When the callback returns [SQLITE_DENY], the
** [sqlite3_prepare_v2()] or equivalent call that triggered the
** authorizer shall fail
** with an SQLITE_ERROR error code and an error message explaining that
** access is denied. {F12506} If the authorizer code (the 2nd parameter
** to the authorizer callback is anything other than [SQLITE_READ], then
** a return of [SQLITE_IGNORE] has the same effect as [SQLITE_DENY]. 
** If the authorizer code is [SQLITE_READ] and the callback returns
** [SQLITE_IGNORE] then the prepared statement is constructed to
** insert a NULL value in place of the table column that would have
** been read if [SQLITE_OK] had been returned. {END}
**
** {F12510} The first parameter to the authorizer callback is a copy of
** the third parameter to the sqlite3_set_authorizer() interface.
** {F12511} The second parameter to the callback is an integer 
** [SQLITE_COPY | action code] that specifies the particular action
** to be authorized. {END} The available action codes are
** [SQLITE_COPY | documented separately].  {F12512} The third through sixth
** parameters to the callback are zero-terminated strings that contain 
** additional details about the action to be authorized. {END}
**
** An authorizer is used when preparing SQL statements from an untrusted
** source, to ensure that the SQL statements do not try to access data
** that they are not allowed to see, or that they do not try to
** execute malicious statements that damage the database.  For
** example, an application may allow a user to enter arbitrary
** SQL queries for evaluation by a database.  But the application does
** not want the user to be able to make arbitrary changes to the
** database.  An authorizer could then be put in place while the
** user-entered SQL is being prepared that disallows everything
** except SELECT statements.  
**
** {F12520} Only a single authorizer can be in place on a database connection
** at a time.  Each call to sqlite3_set_authorizer overrides the
** previous call. {F12521}  A NULL authorizer means that no authorization
** callback is invoked.  {F12522} The default authorizer is NULL. {END}
**
** Note that the authorizer callback is invoked only during 
** [sqlite3_prepare()] or its variants.  {F12523} Authorization is not
** performed during statement evaluation in [sqlite3_step()]. {END}
*/
int sqlite3_set_authorizer(
  sqlite3*,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pUserData
);

/*
** CAPI3REF: Authorizer Return Codes {F12590}
**
** The [sqlite3_set_authorizer | authorizer callback function] must
** return either [SQLITE_OK] or one of these two constants in order
** to signal SQLite whether or not the action is permitted.  See the
** [sqlite3_set_authorizer | authorizer documentation] for additional
** information.
*/
#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */

/*
** CAPI3REF: Authorizer Action Codes {F12550}
**
** The [sqlite3_set_authorizer()] interface registers a callback function
** that is invoked to authorizer certain SQL statement actions.  {F12551} The
** second parameter to the callback is an integer code that specifies
** what action is being authorized.  These are the integer action codes that
** the authorizer callback may be passed. {END}
**
** These action code values signify what kind of operation is to be 
** authorized.  {F12552} The 3rd and 4th parameters to the authorization
** callback function will be parameters or NULL depending on which of these
** codes is used as the second parameter. {F12553} The 5th parameter to the
** authorizer callback is the name of the database ("main", "temp", 
** etc.) if applicable. {F12554} The 6th parameter to the authorizer callback
** is the name of the inner-most trigger or view that is responsible for
** the access attempt or NULL if this access attempt is directly from 
** top-level SQL code.
*/
/******************************************* 3rd ************ 4th ***********/
#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
#define SQLITE_DELETE                9   /* Table Name      NULL            */
#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
#define SQLITE_INSERT               18   /* Table Name      NULL            */
#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
#define SQLITE_READ                 20   /* Table Name      Column Name     */
#define SQLITE_SELECT               21   /* NULL            NULL            */
#define SQLITE_TRANSACTION          22   /* NULL            NULL            */
#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
#define SQLITE_ATTACH               24   /* Filename        NULL            */
#define SQLITE_DETACH               25   /* Database Name   NULL            */
#define SQLITE_ALTER_TABLE