My query does not return what I think should be the Null Values

[Randy]

I have a very simple table. It has 12 fields, but I am only interested in GroupId, and dimension. dimension has what I believe to be some null values. when I run a simple query, both fields as output, and field dimension sorted ascending, I get my correct results. But when I run it with IS NULL as a criteria, I get and empty answer set.
see attached screen shots.

Any idea what I am missing?

 

[pbaldy]

It could be the field contains a ZLS. Try this in the criteria:

""

Or in SQL view try

WHERE Nz(Dimension, "") = ""

which will get both.

 

[Randy]

thank you, the "" worked just fine. I will google ZLS to understand why "" worked but not IS Null. Again many thanks.

 

[pbaldy]

Sorry, been on the road. This may help:

http://www.baldyweb.com/NullEmptyEtc.htm