Or if you’re ready to take it to the ╰[ ⁰﹏⁰ ]╯level then change the column to NChar and use the hex of your favorite emoji like:
DECLARE @testtable1 TABLE ( testid int identity (1,1), testvalue nchar (255))
–use the below for the final query
SELECT ISNULL((SELECT testvalue from @testtable1 where testvalue > 101), NCHAR(0xD83D)+ NCHAR(0xDE20) ) as testvaluethatworks
There are a few other alternatives, such as loading results into a temp table and inserting a default row if the temp table is empty.