PRB: L2029 Error for CRecordset::Check()

The information in this article applies to:

• The Microsoft Foundation Classes (MFC), included with: Microsoft Visual C++ for Windows, version 1.5

SYMPTOMS

The following message may be displayed when you build an application that uses the database classes of the MFC Library:

    error L2029: 'public: virtual int __far __pascal
          CRecordset::Check(short)const __near' : unresolved external

CAUSE

The database classes included with the MFC, version 2.5, were designed for use with the Open Database Connectivity (ODBC) version 1.0 Software Development Kit (SDK) components. If you are using the header files (.H files) included with the ODBC version 2.0 SDK, you will see the L2029 error message shown above.

The CRecordset::Check() function declares a RETCODE as a parameter. RETCODE is defined as an "int" in the SQL.H file included with Visual C++, version 1.5. RETCODE is defined as "signed short" in the SQL.H file included with the ODBC version 2.0 SDK. Because C++ decorates function names based on parameter types, the L2029 error occurs.

RESOLUTION

Do not use the ODBC version 2.0 SDK header files. Remove them from your INCLUDE path. In the Visual C++ Workbench, choose Directories from the Options menu and remove any reference to the ODBC version 2.0 SDK "include" directory.

MORE INFORMATION

Beginning with Microsoft Visual C++ for Windows, version 1.51, and Microsoft Visual C++, 32-bit Edition, version 2.0, the SQL.H file provided is compatible with that provided with the ODBC version 2.0 SDK. The SQL.H file provided with those and newer versions of Visual C++ defines RETCODE as a signed short.