MySQL in a Nutshell, 2nd Edition

Name

SAVEPOINT

Synopsis

SAVEPOINT identifier

Use this statement to identify a point in a transaction to which SQL statements may potentially be undone later. It’s used in conjunction with the ROLLBACK TO SAVEPOINT statement. It may be released with the RELEASE SAVEPOINT statement. You can use any unreserved word to identify a savepoint and can create several savepoints during a transaction. If an additional SAVEPOINT statement is issued with the same name, the previous point will be replaced with the new point for the name given. Here is an example:

START TRANSACTION;
LOCK TABLES orders WRITE;
INSERT DATA INFILE '/tmp/customer_info.sql'
INTO TABLE orders;
SAVEPOINT orders_import;
INSERT DATA INFILE '/tmp/customer_orders.sql'
INTO TABLE orders;

At this point in this example, the administrator can check the results of the orders imported before committing the transactions. If the administrator decides that the orders imported have problems (the /tmp/customer_orders.sql file), but not the client information that was first imported (the /tmp/customer_info.sql file), the following statement could be entered:

ROLLBACK TO SAVEPOINT orders_import;

If the administrator decides that the customer information that was imported also has problems, the ROLLBACK statement can be issued to undo the entire transaction.

As of version 5.0.17 of MySQL, if a stored function or trigger is used, a new savepoint level is set up and the previous savepoints are suspended. When the stored function or trigger is finished, ...