Thursday, April 30, 2009

Using passthrough SQL

With passthrough SQL, you use a TQuery, TStoredProc, or TUpdateSQL component to send an SQL transaction control statement directly to a remote database server. The BDE does not process the SQL statement. Using passthrough SQL enables you to take direct advantage of the transaction controls offered by your server, especially when those controls are non-standard.
To use passthrough SQL to control a transaction, you must

Install the proper SQL Links drivers. If you chose the “Typical” installation when installing C++Builder, all SQL Links drivers are already properly installed.
Configure your network protocol correctly. See your network administrator for more information.
Have access to a database on a remote server.
Set SQLPASSTHRU MODE to NOT SHARED using the SQL Explorer. SQLPASSTHRU MODE specifies whether the BDE and passthrough SQL statements can share the same database connections. In most cases, SQLPASSTHRU MODE is set to SHARED AUTOCOMMIT. However, you can’t share database connections when using transaction control statements. For more information about SQLPASSTHRU modes, see the help file for the BDE Administration utility.

NB:When SQLPASSTHRU MODE is NOT SHARED, you must use separate database components for datasets that pass SQL transaction statements to the server and datasets that do not.

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