ROLLBACK
ROLLBACK — abort the current transaction
Synopsis
ROLLBACK [ WORK | TRANSACTION ] [ AND [ NO ] CHAIN ]
Description
ROLLBACK rolls back the current transaction and causes all the updates made by the transaction to be discarded. 
Parameters
- WORK- TRANSACTION
- Optional key words. They have no effect. 
- AND CHAIN
- If - AND CHAINis 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.
Notes
Use COMMIT to successfully terminate a transaction.
 Issuing ROLLBACK outside of a transaction block emits a warning and otherwise has no effect. ROLLBACK AND CHAIN outside of a transaction block is an error. 
Examples
To abort all changes:
ROLLBACK;
Compatibility
 The command ROLLBACK conforms to the SQL standard. The form ROLLBACK TRANSACTION is a Postgres Pro extension. 

