Begins a write transaction.
BWT marks the beginning of a set of logically related table operations - the start of a write transaction. The end of the transaction is signaled by EWT or the transaction can be aborted with AWT. Transactions are useful when you need to ensure that tables will not be not left inconsistent if some operation in a set of operations fails. Multiple operations can be performed automatically with transactions.
By placing a set of operations between Begin and End transaction functions, you ensure that none of the operations are permanently recorded unless all of the operations are completed successfully.
After calling BWT, an application is allowed to modify data, using ModifyRec, and so on. Calling BWT does not in itself lock the table; other users still have write access. It is only when your application begins making changes to the table or calls LockTable that the table is locked and other applications are refused access. Locked tables remain locked until either AWT or EWT is called.
For more information about write transactions, see the Application Designer’s Guide.