How to populate a ComboBox with a Recordset using VBA

Question

There is some literature available at expert\'s exchange and at teck republic about using the combobox.recordset property to populate a combobox in an Access form.

The

Answer 1

good method with using the Recordset property, thanks for that hint!

Patrick, the method you shown on your page has a big disadvantage (I tried that too on my own): The value list can only be 32 KB, if you exceed this limit the function will throw an error. The callback method has the big disadvantage that it is very slow and it is called once for every entry which makes it unuseable for a longer list. Using the recordset method works very well. I needed this because my SQL string was longer than 32 KB (lot of index values for WHERE ID IN(x,x,x,x,x...)).

Here's a simple function which uses this idea to set a recordset to the combobox:

' Fills a combobox with the result of a recordset.
'
' Works with any length of recordset results (up to 10000 in ADP)
' Useful if strSQL is longer than 32767 characters
'
' Author: Christian Coppes
' Date: 16.09.2009
'
Public Sub fnADOComboboxSetRS(cmb As ComboBox, strSQL As String)
    Dim rs As ADODB.Recordset
    Dim lngCount As Long

   On Error GoTo fnADOComboboxSetRS_Error

    Set rs = fnADOSelectCommon(strSQL, adLockReadOnly, adOpenForwardOnly)

    If Not rs Is Nothing Then
        If Not (rs.EOF And rs.BOF) Then
            Set cmb.Recordset = rs
            ' enforces the combobox to load completely
            lngCount = cmb.ListCount
        End If
    End If

fnADOComboboxSetRS_Exit:
    If Not rs Is Nothing Then
        If rs.State = adStateOpen Then rs.Close
        Set rs = Nothing
    End If
    Exit Sub

fnADOComboboxSetRS_Error:
    Select Case Err
        Case Else
            fnErr "modODBC->fnADOComboboxSetRS", True
            Resume fnADOComboboxSetRS_Exit
    End Select
End Sub

(The function fnADOSelectCommon opens an ADO recordset and gives it back. The function fnErr shows a message box with the error, if there was one.)

As this function closes the opened recordset there should be no problem with the memory. I tested it and didn't saw any increasing of memory which wasn't released after closing the form with the comboboxes.

In the Unload Event of the form you can additionaly use a "Set rs=Me.Comboboxname.Recordset" and then close it. This should not be necessary regarding memory, but it may be better to free up open connections (if used with a backend database server).

Cheers,

Christian