Question

Im trying to return the results of a query into a variable to I am able to use it in a insert statement. However my select keeps returning null even though I believe I have the ISNULL(NULLIF()) set up correctly.

declare @test varchar(10)

set @test =  (select ISNULL(NULLIF(discnumber,''),'NA')
from discmaster
where meteredfilename =  '3501' or nonmeteredfilename='3501')

select @test

It seems correct but still returns a NULL value. Would you Select Case but not 100% sure on that method either.

Answer 1

I’d move the ISNULL outside of the subquery – what if the subquery returns no results?

set @test =  COALESCE(
           (select NULLIF(discnumber,'')
              from discmaster
              where meteredfilename =  '3501' or nonmeteredfilename='3501')
       ,'NA')

(I’ve also been a snob and replaced ISNULL with COALESCE. Outside of a few scenarios, COAELSCE is the better function).