There is a report in Crystal reports that is concatenating three string fields from Dynamics CRM Table. It then takes a distinct count of the records as shown below.
Distinct Count of @RecTotal

Formula @RecTotal is str1+str2+str3

The select record has a criteria
str3 <> "Null" and daterange1 in Last7Days

But there seems to be a discrepancy in the count as the record count seems to take into account Null value as well.

My question to the forum is how does Crystal Reports handle concatenation with Null.

Thanks for the help.