T-SQL CASE Clause: How to specify WHEN NULL

Question

I wrote a T-SQL Statement similar like this (the original one looks different but I want to give an easy example here):

SELECT first_name + 
    CASE last_na         


        

Answer 1

Jason caught an error, so this works...

Can anyone confirm the other platform versions?
SQL Server:

SELECT
CASE LEN(ISNULL(last_name,'')) 
WHEN 0 THEN '' 
ELSE ' ' + last_name
END AS newlastName

MySQL:

SELECT
CASE LENGTH(IFNULL(last_name,'')) 
WHEN 0 THEN '' 
ELSE ' ' + last_name
END AS newlastName

Oracle:

SELECT
CASE LENGTH(NVL(last_name,'')) 
WHEN 0 THEN '' 
ELSE ' ' + last_name
END AS newlastName