BEGIN TRANSACTION Command Example

In the following example, the customer table in the testdata database is opened. Optimistic table buffering is set for the customer table. The contents of the cust_id and company fields are displayed, and then the contents of the company field is replaced within the buffered data.

BEGIN TRANSACTION is issued to start a transaction. The TABLEUPDATE( ) function is used to write the changes to the table. The new contents are displayed, and ROLLBACK is issued to restore the original contents of the company field. The cust_id and company fields are displayed again with the company field containing its original values.

CLEAR
CLOSE DATABASES

* Transactions are only supported within a DBC
OPEN DATABASE (HOME(2) + 'Data\testdata')

SET MULTILOCKS ON      && Required for buffering


USE customer
=CURSORSETPROP("Buffering",5)
? 'The original company field'
LIST FIELDS cust_id, company NEXT 5
REPLACE ALL company WITH "***" && Change field contents

BEGIN TRANSACTION
   =TABLEUPDATE(.T.)
   GO TOP
   ? 'The modified company field'
   LIST FIELDS cust_id, company NEXT 5
   ROLLBACK           && Restore original field contents

=TABLEREVERT(.T.)
GO TOP
? 'The restored company field'
LIST FIELDS cust_id, company NEXT 5