Transaction Control Statements

 Transaction control statements manage the changes made by DML statements and group DML statements into transactions.

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These statements enable you to:

• Make changes to a transaction permanent (COMMIT).

• Undo the changes in a transaction, since the transaction started (ROLLBACK) or since a savepoint (ROLLBACK TO SAVEPOINT). A savepoint is a user-declared intermediate marker within the context of a transaction.

  Note

  The ROLLBACK statement ends a transaction, but ROLLBACK TO SAVEPOINT does not.

• Set a point to which you can roll back (SAVEPOINT).
  

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• Establish properties for a transaction (SET TRANSACTION).

• Specify whether a deferrable integrity constraint is checked following each DML statement or when the transaction is committed (SET CONSTRAINT).
  

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The following example starts a transaction named Update salaries. The example creates a savepoint, updates an employee salary, and then rolls back the transaction to the savepoint. The example updates the salary to a different value and commits.

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SET TRANSACTION NAME 'Update salaries';

SAVEPOINT before_salary_update;

UPDATE employees SET salary=9100 WHERE employee_id=1234 # DML

ROLLBACK TO SAVEPOINT before_salary_update;

UPDATE employees SET salary=9200 WHERE employee_id=1234 # DML

COMMIT COMMENT 'Updated salaries';

See also

• "Introduction to Transactions"

• "When the Database Checks Constraints for Validity"

• Oracle Database SQL Language Reference to learn about transaction control statements