ROLLBACK — abort the current transaction
ROLLBACK [ WORK | TRANSACTION ] [ AND [ NO ] CHAIN ]
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.
AND CHAIN is specified, a new transaction is immediately started with the same transaction characteristics (see SET TRANSACTION) as the just finished one. Otherwise, no new transaction is started.
Use COMMIT to successfully terminate a transaction.
ROLLBACK outside of a transaction block emits a warning and otherwise has no effect.
To abort all changes:
ROLLBACK conforms to the SQL standard. The form
ROLLBACK TRANSACTION is a PostgreSQL extension.