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, ...
Get MySQL in a Nutshell, 2nd Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.