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.
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.
Parent topic: SQL Command Reference