ROLLBACK
|
This document covers the following topics:
For an explanation of the symbols used in the syntax diagram, see Syntax Symbols.
Belongs to Function Group: Database Access and Update
The SQL statement ROLLBACK corresponds to the Natural
statement BACKOUT
TRANSACTION. It undoes all database modifications made since
the beginning of the last recovery unit. A recovery unit may start either after
the beginning of a session or after the last SYNCPOINT,
COMMIT,
END TRANSACTION or
BACKOUT TRANSACTION
statement. This statement also releases all records held during the
transaction.
If a program tries to backout updates which have already been committed by a terminal I/O, a corresponding Natural error message (NAT3711) is returned.
 |
Warning: As all cursors are closed when a logical unit of work ends, a ROLLBACK statement must not be placed within a database
modification loop; instead, it has to be placed outside such a loop or after
the outermost loop of nested loops. |
If an external program written in another standard programming language
is called from a Natural program, this external program should not contain its
own ROLLBACK statement if the Natural program issues database
calls, too. The calling Natural program should issue the ROLLBACK
statement on behalf of the external program.
... DELETE FROM SQL-PERSONNEL WHERE NAME = 'SMITH' ROLLBACK ...
