int sqlite3_close(sqlite3*); int sqlite3_close_v2(sqlite3*);
The sqlite3_close() and sqlite3_close_v2() routines are destructors for the sqlite3 object. Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if the sqlite3 object is successfully destroyed and all associated resources are deallocated.
If the database connection is associated with unfinalized prepared statements or unfinished sqlite3_backup objects then sqlite3_close() will leave the database connection open and return SQLITE_BUSY. If sqlite3_close_v2() is called with unfinalized prepared statements and unfinished sqlite3_backups, then the database connection becomes an unusable "zombie" which will automatically be deallocated when the last prepared statement is finalized or the last sqlite3_backup is finished. The sqlite3_close_v2() interface is intended for use with host languages that are garbage collected, and where the order in which destructors are called is arbitrary.
Applications should finalize all prepared statements, close all BLOB handles, and finish all sqlite3_backup objects associated with the sqlite3 object prior to attempting to close the object. If sqlite3_close_v2() is called on a database connection that still has outstanding prepared statements, BLOB handles, and/or sqlite3_backup objects then it returns SQLITE_OK but the deallocation of resources is deferred until all prepared statements, BLOB handles, and sqlite3_backup objects are also destroyed.
If an sqlite3 object is destroyed while a transaction is open, the transaction is automatically rolled back.
The C parameter to sqlite3_close(C) and sqlite3_close_v2(C) must be either a NULL pointer or an sqlite3 object pointer obtained from sqlite3_open(), sqlite3_open16(), or sqlite3_open_v2(), and not previously closed. Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer argument is a harmless no-op.