Term: ROLLBACK

Definition:
In Oracle PL/SQL, ROLLBACK is a TCL (Transaction Control Language) command, which is used as "undo" feature in SQL. If a transaction or set of transactions has been done on a set of table data, it can be reverted in the same session using the ROLLBACK command.

Example Syntax:

SQL> ROLLBACK;

Example Usage:

The SELECT below statement shows the current data in the TEST table:

SQL> SELECT * FROM TEST;



        ID NAME                 LNAME

---------- -------------------- ----------

         1 CLUB                 ORACLE

         2 SCOTT                HR

The INSERT statement below inserts a new record into the TEST table, and the SELECT statement confirms the insertion of the new record:

SQL> INSERT INTO TEST VALUES (3,'PSOUG','ORACLE');



1 row created.



SQL> SELECT * FROM TEST;



        ID NAME                 LNAME

---------- -------------------- ----------

         1 CLUB                 ORACLE

         2 SCOTT                HR

         3 PSOUG                ORACLE

The ROLLBACK command is now executed to revert back the last set of transactions done on the table:

SQL> ROLLBACK;



Rollback complete.



SQL> SELECT * FROM TEST;



        ID NAME                 LNAME

---------- -------------------- ----------

         1 CLUB                 ORACLE

         2 SCOTT                HR