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Controlling Transactions Manually

  • Articolo

If you want to control transactions manually, you can set the Transactions property to 2, or DB_TRANSMANUAL. With manual transaction handling, Visual FoxPro automatically begins a transaction for you when you issue the first transactable SQL statement, but you must submit the Visual FoxPro SQLCOMMIT( ) or SQLROLLBACK( ) functions to end the transaction.

To use manual transaction mode

  • Use the DBSETPROP( ) command to set the Transactions property on the connection to 2 or DB_TRANSMANUAL.

    -or-

  • Use the SQLSETPROP( ) command to set the Transactions property on the active connection to 2 or DB_TRANSMANUAL.

Transaction processing is handled manually through SQLCOMMIT( ) and SQLROLLBACK( ).

After committing or rolling back the prior transaction, Visual FoxPro automatically begins a new transaction when you issue the next transactable SQL statement. For more information about transactions, see Programming for Shared Access.

Nested Transactions

Visual FoxPro supports transactions nested up to five levels for local data. A single level of transaction support is built into SQL pass-through.

If your server supports multiple levels of transactions, you can use SQL pass-through to manage transaction levels explicitly. Explicit transaction management is complex, however, because it can be difficult to control the interaction between the built-in transaction and the timing of remote server transactions. For more information on explicit transaction management, see your ODBC documentation.

See Also

Using Automatic Transaction Mode | Working with Remote Data Using SQL Pass-Through | Using SQL Pass-Through Technology | Implementing a Client/Server Application | Designing Client/Server Applications | Upsizing Visual FoxPro Databases | Creating Views