SAVEPOINT
Defines or resets the position of a rollback point in the current transaction.
Syntax
SAVEPOINT spVname [
UNIQUE]
- spname is the savepoint identifier.
Usage
The SAVEPOINT
instruction declares a new rollback label at the current position
in the lexical order within the current transaction. After defining a savepoint, you can rollback to
the specified point in the transaction by using the ROLLBACK WORK TO SAVEPOINT
instruction.
If the same savepoint
name was used in a prior SAVEPOINT
instruction, the
previous savepoint is destroyed and the name is reused
to flag the new rollback position. The optional UNIQUE
keyword
specifies that you do not want to reuse the same savepoint
name in a subsequent SAVEPOINT
instruction.
Reusing the same name after a SAVEPOINT
spname UNIQUE
will raise an SQL
error.
Example
In this example, a first savepoint is defined before the INSERT
statement, then reset before the UPDATE
statement.
The ROLLBACK TO SAVEPOINT
instruction will cancel the
UPDATE
statement only:
MAIN
DATABASE stock
BEGIN WORK
DELETE FROM items
SAVEPOINT sp1
INSERT INTO items VALUES ( ... )
SAVEPOINT sp1 -- releases previous savepoint named sp1
UPDATE items SET ...
ROLLBACK WORK TO SAVEPOINT sp1
COMMIT WORK
END MAIN