Pdo\Sqlite::createFunction Registers a user-defined function for use in SQL statements &reftitle.description; public boolPdo\Sqlite::createFunction stringfunction_name callablecallback intnum_args-1 intflags0 This method allows PHP function to be registered with SQLite as a user-defined function, so that it can be called within SQL queries. The defined function can be used in any SQL query that allows function calls, for example SELECT, UPDATE, or triggers. By using this method it is possible to override native SQL functions. &reftitle.parameters; function_name The name of the function used in SQL statements. callback Callback function to handle the defined SQL function. Callback functions should return a type understood by SQLite (i.e. scalar type). This function need to be defined as: mixedcallback mixedvalue mixedvalues value The first argument passed to the SQL function. values Further arguments passed to the SQL function. num_args The number of arguments that the SQL function takes. If this parameter is -1, then the SQL function may take any number of arguments. flags A bitmask of flags. Currently, only Pdo\Sqlite::DETERMINISTIC is supported, which specifies that the function always returns the same result given the same inputs within a single SQL statement. &reftitle.returnvalues; &return.success; &reftitle.examples; In this example, we have a function that calculates the SHA256 sum of a string, and then reverses it. When the SQL statement executes, it returns the value of the filename transformed by our function. The data returned in $rows contains the processed result. The beauty of this technique is that there is no need to process the result using a &foreach; loop after the query. createFunction('sha256rev', 'sha256_and_reverse', 1); $rows = $db->query('SELECT sha256rev(filename) FROM files')->fetchAll(); ?> ]]> &reftitle.seealso; Pdo\Sqlite::createAggregate Pdo\Sqlite::createCollation sqlite_create_function sqlite_create_aggregate