PRB: MFC ODBC Cannot Update Access Date/Time with No Date

 Last reviewed: February 23, 1998
Article ID: Q181480
The information in this article applies to:
  • The Microsoft Foundation Classes (MFC) included with: 

        - Microsoft Visual C++, 32-bit Editions, versions 5.0
  • Microsoft Access 97

SYMPTOMS

When you update records in an Access database using the ODBC cursor library and you previously added a date/time field in Access without a date using the CRecordset (with TIMESTAMP_STRUCT) classes, MFC throws the following exception: 

   No Rows Affected

CAUSE

The ODBC WHERE clause fails to find the record it needs to update it.

RESOLUTION

You must always enter a date in the Access date/time field for CRecordset classes using the ODBC cursor library.

You can also resolve this problem by switching to dynasets.

MORE INFORMATION

If you have to use the ODBC cursor library, you must always enter a date along with a time in the Access date/time field. If you only enter a time, the recordset will fail to post updates and the MFC exception "No Rows Affected" will be thrown. This occurs because the ODBC cursor library attempts to update the database using an UPDATE clause and attempts to select all columns to ensure a unique record. During this selection, the date field fails to be resolved.

If you do not have to use the ODBC cursor library, you can open the recordset as a dynaset, which effectively eliminates this problem.

REFERENCES
Visual C++, Microsoft Foundation Class Reference, Class Library Reference: Crecordset; CDatabase 
Keywords          : MfcDatabase
Component         : jet
Technology        : odbc kbmfc
Version           : WIN95:97,5.0 WINNT:97,5.0
Platform          : Win95 winnt
Issue type        : kbprb

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Last reviewed: February 23, 1998
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