Erik Darling has a video for us:
A Difference Between ISNULL And COALESCE You Might Care About In SQL Server
There’s nothing for me to snip as the graf. I don’t often link to videos without any sort of text accompaniment, but it’s been too long since I’ve linked to Erik and this was an interesting topic.
Bonus points for using “case expression” instead of the more common but technically incorrect “case statement.”