ROLLBACK
From Oracle FAQ
ROLLBACK is an SQL command used to undo changes made to the database (restore data to its state prior to the user making changes).
Example:
INSERT INTO tab1 VALUES ('val1', 'val2', 'val3'); ROLLBACK;
Partial rollback[edit]
One can specify savepoints to mark a point in a transaction to rollback to. Example:
DELETE FROM emp WHERE empno = 123; SAVEPOINT x; UPDATE emp SET sal = sal * 1.1; ROLLBACK TO SAVEPOINT x; COMMIT;