How do I query for NOT NULL?

I'm trying to set up a CountIf expression, and I can't figure out how to set the query to find when a column value exists. When I put in a column name into the operator, the editor returns an "Unknown Field" error. It seems like the editor only accepts True/False expressions, but doesn't accept a column name by itself as a valid expression.

Does anyone know how to work around this?

Hi @awei
I would recommend that you read this:
And try with CountIf(isNull([some_field]))

FYI my current solution has been to use the following equation:
Count - CountIf(isnull([column]).
How hard can it be to just make a CountIf([column]) operator?

@awei Then use CountIf(NOT isnull([column]) if you are trying to not get the nulls.

@flamber thank you. I didn't realize the NOT operator was available.