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

In what way does it "not work"? Does it produce an error when you try to execute it? Does it return an unexpected result?

Off the top of my head, there are several problems:

Your case statement returns 1 in all cases.

The case statement is also combining two different types of CASE semantics:

CASE @Period 
WHEN  THEN 
WHEN  THEN 
ELSE 
END

or

CASE
WHEN @Period =  THEN 
WHEN @Period =  THEN 
ELSE 
END

The second form allows you to use unrelated conditions, whereas the first can only check for different values of @Period.

Further, you're returning the value of @Period, not the value generated by the CASE statement.