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is null vs zero length
Bill Sylvester 
    
6 years ago
in the data validation lesson in thebeginner section
I understood that null meant "never had any data"
where as if it did once have data and someone deleted it, it would then be a zero length string rather than null.
When you were demonstrating the isnull function for queries you deleted a couple of states and those records showed up as isnull.
Im confused
Richard Rost  @Reply  
          
6 years ago
It can be confusing, yes. NULL usually refers to data that isn't there or has been deleted. Usually. It can be different in tables vs. VBA programming, where you can set variables equal to "" or NULL. I explain it more when you get into programming. For now, just keep in mind that you may have to check for both situations.

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