Revision as of 06:30, 12 March 2009

SET ROLLBACK

Class

Multi-User

Purpose

Enable or disable automatic rollback

Syntax

SET ROLLBACK ON | OFF | (<expL>)

See Also

BEGIN TRANSACTION, END TRANSACTION, RESET IN, ROLLBACK, COMPLETED(), ISMARKED(), ROLLBACK()

Description

The SET ROLLBACK ON command invokes automatic rollback and recovery in all tables affected by transactions performed within a BEGIN TRANSACTION....END TRANSACTION block. A ’rollback’ causes record contents to be restored to their value before modification (e.g. at the time BEGIN TRANSACTION was issued). This is particularly useful if an error occurs during the execution of a program or if an Applications Data Dictionary validation constraint is not satisfied.

When BEGIN TRANSACTION is issued all currently open files and all files opened between BEGIN and END TRANSACTION will have Before Image Journaling invoked automatically. To disable rollback for a particular workarea, see the RESET IN command. Recital Corporation recommends the use of the SET ROLLBACK ON command to obtain automatic rollback and recovery on multi-statement transactions. By default, ROLLBACK is OFF.

Example

use setcomm
set rollback on
 
begin transaction
    delete first 15
    replace all t1 with (t2*t3)/100
    list
end transaction
 
if completed()    && determine if the transaction was successful
    dialog box "Transaction completed"
else
    dialog box "Errors occurred during transaction"
endif

Products

Recital Database Server, Recital Mirage Server, Recital Terminal Developer