Microsoft KB Archive/174403

= FIX: Unresolved Externals When Building MFC42 and MFCD42xD =

Article ID: 174403

Article Last Modified on 11/21/2006

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APPLIES TO


 * Microsoft Foundation Class Library 4.2

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This article was previously published under Q174403



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:

170365 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

