FIX: Error in VBA6.DLL Using a Late Bound Recordset When at BOF or EOF (304267)


The information in this article applies to:

  • Microsoft Visual Basic Enterprise Edition for Windows 6.0, when used with:
    • Microsoft Data Access Components 2.6
    • Microsoft Data Access Components 2.6 SP1
    • Microsoft Data Access Components 2.7
  • Microsoft Visual Basic Professional Edition for Windows 6.0, when used with:
    • Microsoft Data Access Components 2.6
    • Microsoft Data Access Components 2.6 SP1
    • Microsoft Data Access Components 2.7
  • Microsoft Visual Basic Learning Edition for Windows 6.0, when used with:
    • Microsoft Data Access Components 2.6
    • Microsoft Data Access Components 2.6 SP1
    • Microsoft Data Access Components 2.7
This article was previously published under Q304267

SYMPTOMS

If you reference a field value in an ActiveX Data Objects (ADO) recordset when BOF or EOF is true, if you use late binding, and if you concatenate it to a string, an unhandled exception occurs in VBA6.DLL and causes an error.

Under Windows 95 or Windows 98, you receive the following error message:
VB6 Has Caused An Error in VBA6.DLL
Under Windows NT 4.0, you receive the following Dr. Watson error:
An application error has occurred and an application error log is being generated. VB6.EXE. Exception: access violation (0xc0000005) address 0x0fa91abd
Under Windows 2000, Visual Basic quits.

CAUSE

If you pass a reference to an ADO field value when BOF or EOF is true, the following error message normally appears:
Either BOF or EOF is true, or the current record has been deleted. Requested operation requires a current record.
However, if you reference a field value in an ADO recordset when BOF or EOF is true, if you use late binding, and if you concatenate it to a string, an unhandled exception occurs in VBA6.DLL and causes the above-mentioned error messages.

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article. This bug was corrected in Visual Basic 6.0 Service Pack 3.

MORE INFORMATION

Steps to Reproduce Behavior

  1. Open a new Standard EXE project in Visual Basic. Form1 is created by default.
  2. Place a command button on Form1.
  3. Add the following code to the button's click event:
      Dim strConn As String
  Dim strSQL As String
  
  strConn = "provider=sqloledb;data source=stevenbr01;initial catalog=northwind;user id=sa;"
  strSQL = "SELECT * FROM Customers"
  
  Set cn = CreateObject("ADODB.Connection")
  Set rs = CreateObject("ADODB.Recordset")
  
  cn.Open strConn
  
  rs.CursorLocation = 3
  rs.Open strSQL, cn, 1, 1
  
  While Not rs.EOF
    For i = 0 To rs.fields.Count - 1
      If Not IsNull(rs.fields(i).Value) Then
        Debug.Print rs.fields(i).Value & ""
      End If
    Next
    rs.movenext
  Wend
   
  Debug.Print "value " & rs.fields("contactname") '<this fails
  'Debug.Print rs.fields("contactname") '<this works
  4. Modify the ADO connection string in the strConn variable as appropriate for your environment.
  5. Run the project, and click the command button. Notice that data scrolls by in the Immediate window. When the recordset is fully read, you receive the above-mentioned error messages.
  6. To see the error that should occur under these circumstances, comment the first Debug.Print line and uncomment the second one, which does not concatenate the field value to the word "value " in the print statement. Then, rerun the project.
Modification Type:MajorLast Reviewed:5/8/2003
Keywords:kbBug kbfix kbVBp600fix KB304267
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