FIX: "Data Truncated Column" Erroneously Reported

ID: Q140534

The information in this article applies to:

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

SYMPTOMS

The following ODBC error message occurs each time the application moves to a another record (X represents the column number):

Warning: ODBC Success With Info, Data truncated column X.
State:01004,Native:0,Origin:[Microsoft][ODBC Single-Tier Driver]

CAUSE

The message occurs when you use CLongBinary field variables with database tracing enabled. Database tracing is enabled by running Tracer.exe and selecting the DB Tracing check box.

In the RFX_LongBinary() function, the following code returns the SQL_SUCCESS_INFO warning:


   case CFieldExchange::Fixup:
   // Give empty buffer to find size of entire LongBinary
   AFX_SQL_ASYNC(pFX->m_prs, ::SQLGetData(pFX->m_prs->m_hstmt,
        (unsigned short int)nField, SQL_C_DEFAULT, &w, 0, plLength));

The RFX routine determines the size of the binary field by calling SQLGetData() with a zero-length buffer. The variable plLength provides the length of the binary field after the call. Because a zero-length buffer is passed to SQLGetData(), ODBC returns a warning indicating that there may be a problem.

RESOLUTION

Ignore the warning.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This problem is fixed in Visual C++ 4.0, and no reports were made for Visual C++ 2.x.

NOTE: Visual C++ 4.0 is a 32-bit product; therefore, the bug is not fixed in any version of 16-bit Visual C++.

Additional query words: 2.50 2.51 2.52

Keywords : kbDatabase kbMFC kbODBC kbVC kbVC400fix
Version : winnt:
Platform : winnt
Issue type : kbbug