(PHP 4 >= 4.0.2, PHP 5 <= 5.0.5, PECL ingres >= 1.0.0)
ingres_rollback — Roll back a transaction
ingres_rollback() rolls back the currently open transaction, actually cancelling all changes made to the database during the transaction.
This closes the transaction. A new transaction can be opened by sending a query with ingres_query().
The connection link identifier
成功时返回 TRUE， 或者在失败时返回 FALSE.