KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q191624: INFO: Do Visual FoxPro Datasources Work Under MTS?

Article: Q191624
Product(s): Microsoft FoxPro
Version(s): WINDOWS:6.0
Operating System(s): 
Keyword(s): 
Last Modified: 12-AUG-1999

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 6.0 
-------------------------------------------------------------------------------

SUMMARY
=======

One of the great new features of Visual FoxPro 6.0 is improved support for
Microsoft Transaction Server (MTS) Server. However, there are some issues to be
aware of when using Visual FoxPro data within MTS.

MORE INFORMATION
================

Microsoft Transaction Server is a critical technology for creating distributed
applications that scale to Enterprise requirements. Part of the MTS appeal is
its automatic transaction support. Distributed components can all participate in
transactions which are Atomic in nature and retain their transaction state
across multiple component calls. With MTS 2.0, transactions are limited
primarily to actions taken against databases such as record inserts, deletes and
updates.

In order to support MTS transactions, a datasource must utilize the Microsoft
Distributed Transaction Coordinator. Databases, such as SQL Server and Oracle,
support transaction protocols that permit them to work with a design-time
control (DTC). SQL Server supports OLE Transactions while Oracle uses XA
Transaction support. This allows one component to perform an action against one
of these databases and have another one abort it so that its actions are
automatically rolled back.

Unfortunately, Visual FoxPro databases do not support either of the transaction
protocols needed to work with MTS distributed transactions. While this limits
the use of Visual FoxPro data in MTS transactions, there are still plenty of
valuable uses for Visual FoxPro data such as meta data. In addition, many
applications do not necessarily require strict distributed transaction support.
Fortunately, there are many solutions around this problem. You might consider
using the MTS Shared Property Manager to set a property that your Visual FoxPro
server can check throughout the lifetime of the transaction and perform its own
rollback/commit.

NOTE: Visual FoxPro's own native transactions still work, but since they do not
go through the Microsoft DTC, they do not participate in the distributed ones
managed by MTS.

REFERENCES
==========

Microsoft Visual FoxPro Help

Microsoft Transaction Server Help

Additional query words: PGFest600 kbVFp600 kbMTS

======================================================================
Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbVFP600
Version           : WINDOWS:6.0
Issue type        : kbinfo

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.