Multiple WHEN inside no-expression CASE in SQL?

Question

    DECLARE @TestVal int
SET @TestVal = 5

SELECT
    CASE
        WHEN @TestVal <=3 THEN 'Top 3'
        ELSE 'Other'
    END

I saw this sample code online but I couldn't find an example where there was no expression and it had more than one WHEN, so I am wondering if this type of thing is OK:

    DECLARE @TestVal int
SET @TestVal = 5

SELECT
    CASE
        WHEN @TestVal <=3 THEN 'Top 3'
                WHEN (select ...) = 1 THEN 'Other Value'
                WHEN (select ...) = 2 THEN 'Other Value 2'
        ELSE 'Other'
    END

Or do I need to say CASE WHEN for each line?

Answer 1

Yes, that's fine, but I would line up the "WHEN"s vertically and explain it more like this:

SELECT
    CASE
        WHEN @TestVal <=3  THEN 'Top 3'
        WHEN @TestVal <=10 THEN 'Top 10'
        WHEN @TestVAl <=25 THEN 'Top 25'
        ELSE 'Other'
    END

The formatting might just be a markdown glitch, but the (select...) in your example complicated what should be a simpler snippet.

Answer 2

Case takes the following form

CASE WHEN Condition THEN Result
     WHEN Condition2 THEN Result2
ELSE Default
END

Edit

This assumes your using Microsoft SQL Server other DBMS might be different