ROLLBACK
ROLLBACK — abort the current transaction
Synopsis
ROLLBACK [ WORK | TRANSACTION ]
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. 
Notes
Use COMMIT to successfully terminate a transaction.
 Issuing ROLLBACK outside of a transaction block emits a warning and otherwise has no effect. 
Examples
To abort all changes:
ROLLBACK;
Compatibility
 The SQL standard only specifies the two forms ROLLBACK and ROLLBACK WORK. Otherwise, this command is fully conforming.