Question

How I can rewrite following query that I will take minus Correction and Used only when they are not null.

select Amount - Correction - Used 
    from CompList 
    where (CompID ='D999999' and  Amount IS NOT NULL) ; 

Thanks for help.

Answer 1

Use the COALESCE function (which returns the first non-null value):

select Amount - COALESCE(Correction, 0) - COALESCE(Used, 0) ....