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

Declare a second variable and then set that value because you aren't resetting @Period.

For example:

DECLARE @Output AS INT

SELECT @Output = CASE @Period 
                 WHEN 1 then 1     
                 WHEN @Period > 1 AND @Period <= 7 THEN 1      -- Should be 2 
                 WHEN @Period > 7 AND @Period <= 30 THEN 1     -- Should be 3
                 WHEN @Period > 30 AND @Period<= 90 THEN 1     -- Should be 4
                 WHEN @Period > 90 AND @Period <= 180 THEN 1   -- Should be 5  
                 WHEN @Period > 180 AND @Period <= 360 THEN 1  -- Should be 6   
                 ELSE 0 END;

RETURN @Output;

I have left it like this as I'm assuming you are going to change your values for each of these CASE statements.