FIX: Access Bit Fields and MDAC 2.1

ID: Q221184

The information in this article applies to:

Microsoft Data Access SDK, version 2.1

SYMPTOMS

When inserting data into a Bit (Yes/No) field in a Microsoft Access database via the Microsoft Access ODBC driver, the resulting data in the bit field is always False, even when a value of True was specified.

This behavior occurs when using the Microsoft Access/Jet ODBC driver provided with MDAC 2.1, version 4.0.3513, and MDAC 2.1 SP1, version 4.0.3711.

CAUSE

The Microsoft Access ODBC driver (Odbcjt32.dll) is incorrectly using 2 bytes rather than a single byte when calculating the offset to the data for the bit field. This offset does not contain the correct value, and the data is inserted into the database as False.

STATUS

This problem has been resolved in the Microsoft Access ODBC/Jet Driver provided with Microsoft Data Access Components 2.1 Service Pack 2.

You may download Microsoft Data Access Components 2.1 Service Pack 2 from the following site:

http://www.microsoft.com/data/download.htm

Alternatively, you may acquire the hotfix version of the Microsoft Access ODBC driver that addresses this problem for earlier versions of Microsoft Data Access Components 2.1. A supported fix that corrects this problem is now available from Microsoft, but it has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://www.microsoft.com/support/supportnet/overview/overview.asp

The English version of this fix should have the following file attributes or later:


  Date      Time   Version      Size   File name   Platform
  ---------------------------------------------------------
  03/18/99         4.0.3918.0   301KB  Odbcjt32.dll

This hotfix is engineered to work with Microsoft Data Access Components (MDAC) build 2.1.

Installation instructions:

Locate Odbcjt32.dll in the system folder.

Verify that no applications or services are using the driver, then rename the driver.

Acquire the hotfix version of the driver.

Copy the new driver into the system folder.

MORE INFORMATION

Steps to Reproduce Behavior

The code sample below uses RDO to demonstrate the behavior described above. After the code has run, notice that the values in the TrueFalse table have been set to False despite True being specified.



    Dim szSQL$
    Dim rdorst As rdoResultset
    Dim mrdoEnv As rdoEnvironment
    Dim mrdoConn As rdoConnection
    Dim mbConnOpen As Boolean

   'Initialize the Environment.
    rdoEngine.rdoDefaultCursorDriver = rdUseServer
    Set mrdoEnv = rdoEngine.rdoCreateEnvironment("TrueFalseTest", "", "")
    mrdoEnv.UserName = "admin"
    
   
    Set mrdoConn = mrdoEnv.OpenConnection(DSName:="Northwind", Prompt:=rdDriverComplete, _
                                           ReadOnly:=False, Connect:="pwd=;")
        
    
    mrdoConn.QueryTimeout = 60
    mbConnOpen = True
   
    
    szSQL = "Create table TrueFalse(Check1 bit, Check2 bit)"
    mrdoConn.Execute szSQL
        
        
    szSQL = "SELECT * FROM TrueFalse"
    Set rdorst = mrdoConn.OpenResultset(szSQL, rdOpenKeyset, rdConcurRowVer)

    rdorst.AddNew

    rdorst!Check1 = True
    rdorst!Check2 = True
    
    rdorst.Update
    rdorst.Close

Additional query words: bit field false odbcjt32.dll access insert incorrect MDAC 2.1 Jet

Keywords : kbAccess kbADO201fix kbDatabase kbDriver kbJET kbMDAC kbODBC210fix kbGrpVBDB kbGrpMDAC kbDSupport kbADO210sp2 kbADO210sp2fix
Version : WINDOWS:2.1
Platform : WINDOWS
Issue type : kbbug