DOCUMENT:Q174403  04-MAY-2001  [visualc]
TITLE   :FIX: Unresolved Externals When Building MFC42 and MFCD42xD
PRODUCT :Microsoft C Compiler
PROD/VER:winnt:5.0sp1,5.0sp2
OPER/SYS:
KEYWORDS:kbDLL kbMFC kbVC500bug kbVS97sp3fix kbGrpDSMFCATL kbNoUpdate

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

 - The Microsoft Foundation Classes (MFC), used with:
    - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0sp1 
    - Microsoft Visual C++, 32-bit Professional Edition, version 5.0sp1 
    - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0sp2 
    - Microsoft Visual C++, 32-bit Professional Edition, version 5.0sp2 
-------------------------------------------------------------------------------

SYMPTOMS
========

When rebuilding Mfc42.dll, Mfcd42d.dll, or Mfcd42ud.dll after installing Visual
Studio 97 Service Pack 1 or Service Pack 2, the "LNK2001: unresolved external
symbol" error message occurs for the following functions:

   AfxThunkSQLDescribeColA
   AfxThunkSQLDriverConnectA
   AfxThunkSQLErrorA
   AfxThunkSQLExecDirectA
   AfxThunkSQLGetCursorNameA
   AfxThunkSQLGetInfoA
   AfxThunkSQLPrepareA
   AfxThunkSQLSetConnectOptionA

CAUSE
=====

The symbols generated for these functions when compiling the file Dbcore.cpp do
not match the function definitions specified for export in Mfc42.def,
Mfcd42d.def, or Mfcd42ud.def.

RESOLUTION
==========

Modify the function definitions in Mfc42.def, mfcd42d.def, or mfcd42ud.def to
match the symbols for the function generated when compiling Dbcore.cpp.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug has been fixed in Visual Studio 97 Service
Pack 3.

For more information, please see the following article in the Microsoft Knowledge
Base:

   Q170365 INFO: Visual Studio 97 Service Packs - What, Where, and Why

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

The difference between the function definitions in Dbcore.cpp and Mfc42.def,
Mfcd42d.def, or Mfcd42ud.def is that the function definitions have an "A"
appended to the function names in Mfc42.def, Mfcd42d.def, or Mfcd42ud.def.

These functions exist in Dbcore.cpp without the "A" appended to the function
name.

Remove the "A" from the function names in question for the .def file you specify
when rebuilding Mfc42.dll, Mfcd42d.dll, or Mfcd42ud.dll.

For example:

Change the following

      ?AfxThunkSQLDescribeColA@@YGFPAXGPAEFPAF2PAK22@Z @ 1507 NONAME

to the following:

      ?AfxThunkSQLDescribeCol@@YGFPAXGPAEFPAF2PAK22@Z @ 1507 NONAME

REFERENCES
==========

See the section "Building the MFC DLL" in TN033 for information on how to
rebuild the MFC DLL.

(c) Microsoft Corporation 1997, All Rights Reserved. Contributions by Isaac
Varon, Microsoft Corporation.
(c) Microsoft Corporation 1997, All Rights Reserved.
Contributions by Isaac Varon, Microsoft Corporation


Additional query words: AfxThunkSQL

======================================================================
Keywords          : kbDLL kbMFC kbVC500bug kbVS97sp3fix kbGrpDSMFCATL kbNoUpdate 
Technology        : kbAudDeveloper kbMFC
Version           : winnt:5.0sp1,5.0sp2
Issue type        : kbbug
Solution Type     : kbfix

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

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.

Copyright Microsoft Corporation 2001.