About Transaction Control Statements

A transaction is a sequence of one or more SQL statements that Oracle Database treats as a unit: either all of the statements are performed, or none of them are.

You need transactions to model business processes that require that several operations be performed as a unit. For example, when a manager leaves the company, a row must be inserted into the JOB_HISTORY table to show when the manager left, and for every employee who reports to that manager, the value of MANAGER_ID must be updated in the EMPLOYEES table. To model this process in an application, you must group the INSERT and UPDATE statements into a single transaction.

The basic transaction control statements are:

• SAVEPOINT, which marks a savepoint in a transaction—a point to which you can later roll back. Savepoints are optional, and a transaction can have multiple savepoints.

• COMMIT, which ends the current transaction, makes its changes permanent, erases its savepoints, and releases its locks.

• ROLLBACK, which rolls back (undoes) either the entire current transaction or only the changes made after the specified savepoint.

In the SQL*Plus environment, you can enter a transaction control statement after the SQL> prompt.

In the SQL Developer environment, you can enter a transaction control statement in the SQL Worksheet. SQL Developer also has Commit Changes and Rollback Changes icons, which are explained in "Committing Transactions" and "Rolling Back Transactions".