KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q166939: BUG: CRecordset::Update Fails After Upgrading

Article: Q166939
Product(s): Microsoft C Compiler
Version(s): 4.2 4.2b 5.0
Operating System(s): 
Keyword(s): kbVC500bugkbbuglist
Last Modified: 04-AUG-2001

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

- Microsoft Visual C++, 32-bit Enterprise Edition, versions 4.2, 4.2b, 5.0 
- Microsoft Visual C++, 32-bit Professional Edition, versions 4.2, 4.2b, 5.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

After you recompile it with Visual C++ 4.2 or Visual C++ 5.0, an MFC/ODBC
application built with Visual C++ 4.0 or 4.1 begins to fail in
CRecordset::Update.

CAUSE
=====

MFC 4.2 removes the "FOR UPDATE OF" clause from SELECT statements generated for
all CRecordset objects.

Some ODBC drivers depend on this syntax and will fail to process the SQL when it
is not found.

RESOLUTION
==========

A member variable CDatabase::m_bAddForUpdate was added in MFC 4.2 to internally
control the inclusion of the "FOR UPDATE" clause.

Setting this variable to TRUE before opening the recordset will cause "FOR
UPDATE" to be appended to the generated SQL statement.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. We are researching this bug and will post new
information here in the Microsoft Knowledge Base as it becomes available.

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

CDatabase::m_bAddForUpdate is an undocumented member of CDatabase and as such is
not guaranteed to have the same use or even exist in future versions of MFC.

It is offered for use in this article as a workaround only for this current
problem.

This problem is not believed to affect many ODBC drivers.

Additional query words: kbvc420bug kbvc500bug kbmfc kbdatabase kbodbc

======================================================================
Keywords          : kbVC500bug kbbuglist
Technology        : kbVCsearch kbAudDeveloper kbVC420 kbVC500 kbVC32bitSearch kbVC420b kbVC500Search
Version           : 4.2 4.2b 5.0
Issue type        : kbbug

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

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.