| Navigation: Language Reference > 13 - Built-in Functions >====== ROLLBACK (terminate unsuccessful transaction) ====== |    |
ROLLBACK
The ROLLBACK statement terminates an active transaction. Execution of a ROLLBACK statement assumes that the transaction was unsuccessful and the database must be restored to the state it was in before the transaction began.
ROLLBACK informs the file driver involved in the transaction that the temporary files containing the information necessary to restore the database to its previous state must be used to restore the database. The file driver then performs the actions necessary to its file system to roll back the transaction.
Errors Posted:
| 65 | Unable to ROLLBACK Transaction |
| 91 | No Logout Active |
Example:
LOGOUT(1,OrderHeader,OrderDetail) !Begin Transaction
DO ErrHandler !always check for errors
ADD(OrderHeader) !Add Parent record
DO ErrHandler !always check for errors
LOOP X# = 1 TO RECORDS(DetailQue) !Process stored detail records
GET(DetailQue,X#) !Get one from the QUEUE
DO ErrHandler !always check for errors
Det:Record = DetailQue !Assign to record buffer
ADD(OrderDetail) !and add it to the file
DO ErrHandler !always check for errors
END
COMMIT !Terminate successful transaction
ASSERT(~ERRORCODE())
ErrHandler ROUTINE !Error routine
IF NOT ERRORCODE() THEN EXIT. !Bail out if no error
ROLLBACK !Rollback the aborted transaction
ASSERT(~ERRORCODE())
BEEP !Alert the user
MESSAGE('Transaction Error - ' & ERROR())
RETURN !and get out
See Also: