You can choose to specify an isolation level when you begin the transaction. The isolation level applies to all commands executed within the transaction.
For more information about isolation levels, see the Adaptive Server Enterprise Performance and Tuning Guide.
The locks that Adaptive Server uses when you enter a Select statement depend on the transaction's isolation level.
The following example uses an AseTransaction object to issue and then roll back a SQL statement. The transaction uses Isolation level 2 (RepeatableRead), which places a Write lock on the row being modified so that no other database user can update the row.