用NULL更新带有表单中文本字段的数值字段

Question

I want to be able to update a numeric column to different values and also be able clear values in a field (set the field to null). I am able to update the field to any number I want but whenever I delete the value and set it to nothing, it's giving me an error.

Here's my code:

Private Sub txtPortNumber_AfterUpdate()

Dim portSQL As String

portSQL = "UPDATE Switches SET [Port Number] = " & Me.txtPortNumber & " WHERE ID = " & Me.txtID3 & ""

DoCmd.RunSQL (portSQL)

Me.Refresh

End Sub

How would you recommend me approaching this issue? I'm thinking that I need to write an IF-ELSE statement but I'm unsure of what to put.

txtID3 is a number and txtPortNumber is also numeric.

Answer 1

Sorry I got started on this, I thought it was VB.NET and not Access. Let me know if this works:

Private Sub txtPortNumber_AfterUpdate()
    Dim portSQL As String
    Dim portNumber as Integer
    Dim myID as Integer 

    If IsNumeric(Me.txtID3) Then 
        myID = CInt(Me.txtID3) 

        If IsNumeric(Me.txtPortNumber) Then
            portNumber = CInt(Me.txtPortNumber) 
            portSQL = "UPDATE Switches SET [Port Number] = " & portNumber & " WHERE ID = " & myID  & ""
        Else
            portSQL = "UPDATE Switches SET [Port Number] = NULL WHERE ID = " & myID  & ""
        End If 
        DoCmd.RunSQL (portSQL)

    End If
    Me.Refresh
End Sub