Thanks for that, but I found this:

https://rextester.com/l/sql_server_online_compiler

Works really well 🙂

I think this will do nicely  - a little bit of test code I tried at here:

https://rextester.com/l/sql_server_online_compiler

DECLARE

@AssetNo AS nvarchar(12) = 'M123',

@Location as nvarchar(12) = null,

@ID AS INT = 42;

SELECT...

That looks like it should - simple - why didn't I think of it!

It's a case of not seeing the wood from the trees because I was going down a...