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How can you check for null in a VBA DAO record set?

I have an optional field in a database that I'm pulling out using a DAO Record Set. I need to check whether or not the field is set before I concatenate it with other fields. So far I have the following code snippet which I've tried with both Is and = (that's the obviously wrong syntax [[Is | =]]) to no avail. It appears that if I use = it will not correctly compare with Null and if I use Is then it complains that it's not comparing with an Object.

While Not rs.EOF
    If rs.Fields("MiddleInitial") [[Is | =]] Null Then thisMiddleInitial = "" Else thisMiddleInitial = rs.Fields("MiddleInitial")
    If prettyName(myLastName, myFirstName, myMiddleInitial) = prettyName(rs.Fields("LastName"), rs.Fields("FirstName"), thisMiddleInitial) Then
        MsgBox "Yay!"
    End If
    rs.MoveNext
Wend

If there's a simpler way to do this I'm totally open to it. prettyName takes 3 Strings as parameters and initially I was just trying to pass rs.Fields("MiddleName") directly but it threw up at a Null value. I'd prefer to do something more direct like that but this is the best I could come up with.

like image 477
Tim Visher Avatar asked Mar 19 '09 21:03

Tim Visher


1 Answers

How about:

IsNull(rs.Fields("MiddleInitial").Value)

You could also have a look at this article which has some explanation about Null values in Access VBA apps and how to handle them.

like image 62
Hamish Smith Avatar answered Sep 18 '22 00:09

Hamish Smith