Is there a solution if there are multiple functions involved. For example:

select field1, sum(nullfield1/IIF(field2>0,nullfield2,nullfield3) as result from sometable group by 1


The problem is I need to run a select that has a formula for a weighted average, not the AVG() function. This requires a difficult expression with several other functions.

I also have the need for an expression in a select that divides two sum() calculations, with the second sum being multiplied by 1000 to get the units correct. I have a specialized divide() function that I wrote that works with nulls, /0 errors, but this still causes problems. Any ideas?