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.
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.
This problem has been resolved in the Microsoft Access ODBC/Jet Driver provided with Microsoft Data Access Components 2.1 Service Pack 2 and later.
You may download the latest Microsoft Data Access Components service pack from the following site:
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 is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next that contains this hotfix.
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 about support costs, visit the following Microsoft Web site:
NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.
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.
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