Aborts the current transaction.
ROLLBACK [WORK | TRANSACTION]
ROLLBACK rolls back the current transaction and causes all the updates made by the transaction to be discarded.
Optional key words. They have no effect.
COMMIT to successfully end the current transaction.
ROLLBACK when not inside a transaction does no harm, but it will provoke a warning message.
To discard all changes made in the current transaction:
The SQL standard only specifies the two forms
ROLLBACK WORK. Otherwise, this command is fully conforming.