How to use a case statement in scalar valued function in SQL?

Question

I want to get one value from a function using a case statement. I tried the following but it does not work:

CREATE FUNCTION [FATMS].[fnReturnByPeriod]
(

            


        

Answer 1

There are two types of CASE expression: simple and searched. You must choose one or the other - you can't use a mixture both types in one expression.

Try this:

SELECT CASE
    WHEN @Period = 1 THEN 1
    WHEN @Period > 1 AND @Period <= 7 THEN 2
    WHEN @Period > 7 AND @Period <= 30 then 3
    -- etc...
    ELSE 0
END

Also, you need to assign the result to something as others have already pointed out.