Sets an attribute on the database handle. Some of the available generic attributes are listed below; some drivers may make use of additional driver specific attributes.
PDO::ATTR_CASE: Force column names to a specific case.
PDO::CASE_LOWER: Force column names to lower case.
PDO::CASE_NATURAL: Leave column names as returned by the database driver.
PDO::CASE_UPPER: Force column names to upper case.
PDO::ATTR_ERRMODE: Error reporting.
PDO::ERRMODE_SILENT: Just set error codes.
PDO::ERRMODE_WARNING: Raise E_WARNING.
PDO::ERRMODE_EXCEPTION: Throw exceptions.
PDO::ATTR_ORACLE_NULLS (available with all drivers, not just Oracle): Conversion of NULL and empty strings.
PDO::NULL_NATURAL: No conversion.
PDO::NULL_EMPTY_STRING: Empty string is converted to NULL.
PDO::NULL_TO_STRING: NULL is converted to an empty string.
PDO::ATTR_STRINGIFY_FETCHES: Convert numeric values to strings when fetching. Requires bool.
PDO::ATTR_STATEMENT_CLASS: Set user-supplied statement class derived from PDOStatement. Cannot be used with persistent PDO instances. Requires array(string classname, array(mixed constructor_args)).
PDO::ATTR_AUTOCOMMIT (available in OCI, Firebird and MySQL): Whether to autocommit every single statement.
PDO::MYSQL_ATTR_USE_BUFFERED_QUERY (available in MySQL): Use buffered queries.