How do I show only null or zero values as a result of an expression?

[#1]

I am reconciling medications dispensed to our charges to ensure all medications are charged for. So I have summed the charges related to the medications and want to only show where there are no charges related to a medication. I am having trouble showing only null or zero values. Any suggestions?

Currently I have the sum of the charges as an expression, so how do I limit the results to only display the zero or missing values?

Thanks!

[crystles]

If you have Meds as a field, then just use an if statement

IF(IsNull(ChargesField), Count(MedsField))

[sunny_talwar]

May be something like this:

If(Len(Trim(YourCurrentExpression)) = 0, 'Null',

If(YourCurrentExpression = 0, 'Zero'))