Paul,

You're very close. Count simply gives you the number of records it encounters. What you put inside the parenthises may affect the performance but it certainly won't affect the result.

Try SUM(IIF(ISNULL(Table1.Rnum) > 0,1,0)) AS RnumTotal.

> Here's where I'm having problems. I'd like to count how many records have a value in the Rnum column (i.e. are not .NULL.). For this example, the total # should be 3. I've tried using:
>
>COUNT(IIF(LEN(Table1.Rnum) > 0,1,0)) AS RnumTotal
>
>But it keeps giving me the same number as the total number of records. What am I missing?