int sqlite3_errcode(sqlite3 *db); int sqlite3_extended_errcode(sqlite3 *db); const char *sqlite3_errmsg(sqlite3*); const void *sqlite3_errmsg16(sqlite3*); const char *sqlite3_errstr(int);
If the most recent sqlite3_* API call associated with database connection D failed, then the sqlite3_errcode(D) interface returns the numeric result code or extended result code for that API call. If the most recent API call was successful, then the return value from sqlite3_errcode() is undefined. The sqlite3_extended_errcode() interface is the same except that it always returns the extended result code even when extended result codes are disabled.
The sqlite3_errmsg() and sqlite3_errmsg16() return English-language text that describes the error, as either UTF-8 or UTF-16 respectively. Memory to hold the error message string is managed internally. The application does not need to worry about freeing the result. However, the error string might be overwritten or deallocated by subsequent calls to other SQLite interface functions.
The sqlite3_errstr() interface returns the English-language text that describes the result code, as UTF-8. Memory to hold the error message string is managed internally and must not be freed by the application.
When the serialized threading mode is in use, it might be the case that a second error occurs on a separate thread in between the time of the first error and the call to these interfaces. When that happens, the second error will be reported since these interfaces always report the most recent result. To avoid this, each thread can obtain exclusive use of the database connection D by invoking sqlite3_mutex_enter(sqlite3_db_mutex(D)) before beginning to use D and invoking sqlite3_mutex_leave(sqlite3_db_mutex(D)) after all calls to the interfaces listed here are completed.
If an interface fails with SQLITE_MISUSE, that means the interface was invoked incorrectly by the application. In that case, the error code and message may or may not be set.