capi3ref.tcl

轻量级数据库软件,嵌入式设计可以考虑考虑,性能不错

 <li>
 When an error occurs, 
 sqlite3_step() will return one of the detailed result-codes
 like SQLITE_IOERR or SQLITE_FULL or SQLITE_SCHEMA directly. The
 legacy behavior was that sqlite3_step() would only return a generic
 SQLITE_ERROR code and you would have to make a second call to
 sqlite3_reset() in order to find the underlying cause of the problem.
 With the "v2" prepare interfaces, the underlying reason for the error is
 returned directly.
 </li>
 </ol>
}

api {} {
void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
} {
 <i>Experimental</i>

 This routine configures a callback function - the progress callback - that
 is invoked periodically during long running calls to sqlite3_exec(),
 sqlite3_step() and sqlite3_get_table().
 An example use for this API is to keep
 a GUI updated during a large query.

 The progress callback is invoked once for every N virtual machine opcodes,
 where N is the second argument to this function. The progress callback
 itself is identified by the third argument to this function. The fourth
 argument to this function is a void pointer passed to the progress callback
 function each time it is invoked.

 If a call to sqlite3_exec(), sqlite3_step() or sqlite3_get_table() results 
 in less than N opcodes being executed, then the progress callback is not
 invoked.
 
 To remove the progress callback altogether, pass NULL as the third
 argument to this function.

 If the progress callback returns a result other than 0, then the current 
 query is immediately terminated and any database changes rolled back. If the
 query was part of a larger transaction, then the transaction is not rolled
 back and remains active. The sqlite3_exec() call returns SQLITE_ABORT. 

}

api {} {
int sqlite3_reset(sqlite3_stmt *pStmt);
} {
 The sqlite3_reset() function is called to reset a prepared SQL
 statement obtained by a previous call to 
 sqlite3_prepare_v2() or
 sqlite3_prepare16_v2() back to it's initial state, ready to be re-executed.
 Any SQL statement variables that had values bound to them using
 the sqlite3_bind_*() API retain their values.
}

api {} {
void sqlite3_result_blob(sqlite3_context*, const void*, int n, void(*)(void*));
void sqlite3_result_double(sqlite3_context*, double);
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);
void sqlite3_result_int(sqlite3_context*, int);
void sqlite3_result_int64(sqlite3_context*, long long int);
void sqlite3_result_null(sqlite3_context*);
void sqlite3_result_text(sqlite3_context*, const char*, int n, void(*)(void*));
void sqlite3_result_text16(sqlite3_context*, const void*, int n, void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int n, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int n, void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
} {
 User-defined functions invoke these routines in order to
 set their return value.  The sqlite3_result_value() routine is used
 to return an exact copy of one of the arguments to the function.

 The operation of these routines is very similar to the operation of
 sqlite3_bind_blob() and its cousins.  Refer to the documentation there
 for additional information.
}

api {} {
int sqlite3_set_authorizer(
  sqlite3*,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pUserData
);
#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          26   /* Database Name   Table Name      */
#define SQLITE_REINDEX              27   /* Index Name      NULL            */
#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
#define SQLITE_FUNCTION             31   /* Function Name   NULL            */

#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 */
} {
 This routine registers a callback with the SQLite library.  The
 callback is invoked by sqlite3_prepare_v2() to authorize various
 operations against the database.  The callback should
 return SQLITE_OK if access is allowed, SQLITE_DENY if the entire
 SQL statement should be aborted with an error and SQLITE_IGNORE
 if the operation should be treated as a no-op.

 Each database connection have at most one authorizer registered
 at a time one time.  Each call
 to sqlite3_set_authorizer() overrides the previous authorizer.
 Setting the callback to NULL disables the authorizer.

 The second argument to the access authorization function will be one
 of the defined constants shown.  These values signify what kind of operation
 is to be authorized.  The 3rd and 4th arguments to the authorization
 function will be arguments or NULL depending on which of the 
 codes is used as the second argument.  For example, if the the
 2nd argument code is SQLITE_READ then the 3rd argument will be the name
 of the table that is being read from and the 4th argument will be the
 name of the column that is being read from.  Or if the 2nd argument
 is SQLITE_FUNCTION then the 3rd argument will be the name of the
 function that is being invoked and the 4th argument will be NULL.

 The 5th argument is the name
 of the database ("main", "temp", etc.) where applicable.  The 6th argument
 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 
 input SQL code.

 The return value of the authorization function should be one of the
 constants SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE.  A return of
 SQLITE_OK means that the operation is permitted and that 
 sqlite3_prepare_v2() can proceed as normal.
 A return of SQLITE_DENY means that the sqlite3_prepare_v2()
 should fail with an error.  A return of SQLITE_IGNORE causes the 
 sqlite3_prepare_v2() to continue as normal but the requested 
 operation is silently converted into a no-op.  A return of SQLITE_IGNORE
 in response to an SQLITE_READ or SQLITE_FUNCTION causes the column
 being read or the function being invoked to return a NULL.

 The intent of this routine is to allow applications to safely execute
 user-entered SQL.  An appropriate callback can deny the user-entered
 SQL access certain operations (ex: anything that changes the database)
 or to deny access to certain tables or columns within the database.
}

api {} {
int sqlite3_step(sqlite3_stmt*);
} {
 After an SQL query has been prepared with a call to either
 sqlite3_prepare_v2() or sqlite3_prepare16_v2() or to one of
 the legacy interfaces sqlite3_prepare() or sqlite3_prepare16(),
 then this function must be
 called one or more times to execute the statement.

 The details of the behavior of this sqlite3_step() interface depend
 on whether the statement was prepared using the newer "v2" interface
 sqlite3_prepare_v2() and sqlite3_prepare16_v2() or the older legacy
 interface sqlite3_prepare() and sqlite3_prepare16().  The use of the
 new "v2" interface is recommended for new applications but the legacy
 interface will continue to be supported.

 In the lagacy interface, the return value will be either SQLITE_BUSY, 
 SQLITE_DONE, SQLITE_ROW, SQLITE_ERROR, or SQLITE_MISUSE.  With the "v2"
 interface, any of the other SQLite result-codes might be returned as
 well.

 SQLITE_BUSY means that the database engine attempted to open
 a locked database and there is no busy callback registered.
 Call sqlite3_step() again to retry the open.

 SQLITE_DONE means that the statement has finished executing
 successfully.  sqlite3_step() should not be called again on this virtual
 machine without first calling sqlite3_reset() to reset the virtual
 machine back to its initial state.

 If the SQL statement being executed returns any data, then 
 SQLITE_ROW is returned each time a new row of data is ready
 for processing by the caller. The values may be accessed using
 the sqlite3_column_int(), sqlite3_column_text(), and similar functions.
 sqlite3_step() is called again to retrieve the next row of data.
 
 SQLITE_ERROR means that a run-time error (such as a constraint
 violation) has occurred.  sqlite3_step() should not be called again on
 the VM. More information may be found by calling sqlite3_errmsg().
 A more specific error code (example: SQLITE_INTERRUPT, SQLITE_SCHEMA,
 SQLITE_CORRUPT, and so forth) can be obtained by calling
 sqlite3_reset() on the prepared statement.  In the "v2" interface,
 the more specific error code is returned directly by sqlite3_step().

 SQLITE_MISUSE means that the this routine was called inappropriately.
 Perhaps it was called on a virtual machine that had already been
 finalized or on one that had previously returned SQLITE_ERROR or
 SQLITE_DONE.  Or it could be the case that a database connection
 is being used by a different thread than the one it was created it.

 <b>Goofy Interface Alert:</b>
 In the legacy interface, 
 the sqlite3_step() API always returns a generic error code,
 SQLITE_ERROR, following any error other than SQLITE_BUSY and SQLITE_MISUSE.
 You must call sqlite3_reset() (or sqlite3_finalize()) in order to find
 one of the specific result-codes that better describes the error.
 We admit that this is a goofy design.  The problem has been fixed
 with the "v2" interface.  If you prepare all of your SQL statements
 using either sqlite3_prepare_v2() or sqlite3_prepare16_v2() instead
 of the legacy sqlite3_prepare() and sqlite3_prepare16(), then the 
 more specific result-codes are returned directly by sqlite3_step().
 The use of the "v2" interface is recommended.
}

api {} {
void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
} {
 Register a function that is called each time an SQL statement is evaluated.
 The callback function is invoked on the first call to sqlite3_step() after
 calls to sqlite3_prepare_v2() or sqlite3_reset().
 This function can be used (for example) to generate
 a log file of all SQL executed against a database.  This can be
 useful when debugging an application that uses SQLite.
}

api {} {
void *sqlite3_user_data(sqlite3_context*);
} {
 The pUserData argument to the sqlite3_create_function() and
 sqlite3_create_function16() routines used to register user functions
 is available to the implementation of the function using this
 call.
}

api {} {
const void *sqlite3_value_blob(sqlite3_value*);
int sqlite3_value_bytes(sqlite3_value*);
int sqlite3_value_bytes16(sqlite3_value*);
double sqlite3_value_double(sqlite3_value*);
int sqlite3_value_int(sqlite3_value*);
long long int sqlite3_value_int64(sqlite3_value*);
const unsigned char *sqlite3_value_text(sqlite3_value*);
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
} {
 This group of routines returns information about arguments to
 a user-defined function.  Function implementations use these routines
 to access their arguments.  These routines are the same as the
 sqlite3_column_... routines except that these routines take a single
 sqlite3_value* pointer instead of an sqlite3_stmt* and an integer
 column number.

 See the documentation under sqlite3_column_blob for additional
 information.
}

api {} {
  int sqlite3_sleep(int);
} {
 Sleep for a little while. The second parameter is the number of
 miliseconds to sleep for. 

 If the operating system does not support sleep requests with 
 milisecond time resolution, then the time will be rounded up to 
 the nearest second. The number of miliseconds of sleep actually 
 requested from the operating system is returned.
}

api {} {
  int sqlite3_expired(sqlite3_stmt*);
} {
 Return TRUE (non-zero) if the statement supplied as an argument needs
 to be recompiled.  A statement needs to be recompiled whenever the
 execution environment changes in a way that would alter the program
 that sqlite3_prepare() generates.  For example, if new functions or
 collating sequences are registered or if an authorizer function is
 added or changed.
}

api {} {
  int sql