FIX: RDO Resultset.Update Using ODBC Cursors Does Not Time Out If Data Is Locked

• Microsoft Visual Basic Professional and Enterprise Editions for Windows, versions 5.0, 6.0

SYMPTOMS

If you're trying to update your rdoResultset on an rdoConnection with a CursorDriver of rdUseOdbc, the attempt to update the data in your database will not time out if that data is locked.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information about Visual Studio service packs, please see the following articles in the Microsoft Knowledge Base:

Q194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

Q194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed

MORE INFORMATION

When you attempt to update data that is locked, most client-server databases, such as SQL Server and Oracle, keep trying to update that data until the length of time specified in the QueryTimeout value has expired. With RDO 2.0 prior to Visual Studio 6.0 Service Pack 3, the QueryTimeout information was not specified in the attempt to update and the attempt would never time out.

This problem only occurs when using an rdoConnection with a value of rdUseOdbc for the CursorDriver property. With all other values for the CursorDriver property, this behavior does not occur.

Steps to Reproduce Behavior

1. Create a new Visual Basic project.



2. Add a reference to RDO 2.0 in your project.



3. Add the following code to your project.




Private Sub Form_Load()
    Dim cn1 As rdoConnection, cn2 As rdoConnection
    Dim rs1 As rdoResultset
    Dim strConn As String, strSQL As String
    
    strConn = "Driver={SQL Server};Server=MyServer;" & _
              "Database=pubs;UID=MyUID;PWD=MyPWD;"
    strSQL = "SELECT * FROM Authors"
    
    Set cn1 = New rdoConnection
    cn1.CursorDriver = rdUseOdbc
    cn1.Connect = strConn
    cn1.EstablishConnection
        
    Set rs1 = cn1.OpenResultset(strSQL, rdOpenKeyset, rdConcurValues)
    
    Set cn2 = New rdoConnection
    cn2.CursorDriver = rdUseOdbc
    cn2.Connect = strConn
    cn2.EstablishConnection
    cn2.BeginTrans
    strSQL = "UPDATE Authors SET Au_FName = 'Test1' " & _
             "WHERE Au_ID = '" & rs1!Au_ID & "'"
    cn2.Execute strSQL

    rs1.Edit
    rs1!Au_FName = "Test2"
    rs1.Update
    
    cn2.RollbackTrans
    cn2.Close
    Set cn2 = Nothing
    
    rs1.Close
    Set rs1 = Nothing
    cn1.Close
    Set cn1 = Nothing
End Sub 

This code assumes that you are using RDO 2.0 to communicate with SQL Server 6.5 or 7.0. You need to modify the connection string to communicate with your database. If you're not using SQL Server, you might also need to modify the query strings.


4. Run the project.

Additional query words:

Keywords          : kbservicepack kbRDO kbRDO200 kbVBp600 kbVS600sp2 kbVS600SP1 kbVS600sp3fix 
Version           : WINDOWS:5.0,6.0
Platform          : WINDOWS 
Issue type        : kbbug 

Last Reviewed: May 19, 1999