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  1. #1
    Paul H's Avatar
    Paul H is offline Expert
    Windows XP Access 2010 32bit
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    Sep 2011
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    Richmond, VA
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    591

    Empty String Function


    I have on ongoing struggle with empty strings vs. null. I've learned a bit over time, but they look the same and of course behave differently. I have written a function to check for both a null and an empty string, "". and then return a substitute value like the NZ function. I'm not sure if it's necessary, but it solves a problem I was having with an empty combo box on my form. NZ was not working so I wrote this.

    Code:
    Public Function NZ_Empty(varString As Variant, strSubstitute As String)
        If IsNull(varString) Or varString = "" Then
            NZ_Empty = strSubstitute
        Else
            NZ_Empty = varString
        End If
    End Function
    I've seen other developers do similar things. This function works in place of NZ. Does Access have something built in like this? I'd appreciate your comments.

  2. #2
    orange's Avatar
    orange is online now Moderator
    Windows XP Access 2003
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    Sep 2009
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    Ottawa, Ontario, Canada; West Palm Beach FL
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    The description and syntax of Nz() and IsNull() are at these links

    http://www.techonthenet.com/access/f...dvanced/nz.php

    http://www.techonthenet.com/access/f...ced/isnull.php

    Lots of posters seem to use blank, empty and Null interchangeably and as you have said
    they behave differently.

    You may find this article by Susan Harkins interesting
    http://www.techrepublic.com/article/...ccess/6125114/

  3. #3
    Missinglinq's Avatar
    Missinglinq is offline VIP
    Windows 7 64bit Access 2007
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    3,016
    Quote Originally Posted by Paul H View Post
    Does Access have something built in like this?
    If you're asking if there is a native (built-in) Function that checks for Nulls and Zero-Length Strings ("")...the answer is no! You have to roll your own, as you've done. There are three or four hacks for doing this, and everyone seems to have one in particular that they like.

    Linq ;0)>
    The problem with making anything foolproof...is that fools are so darn ingenious!

    All posts/responses based on Access 2003/2007

Please reply to this thread with any new information or opinions.

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