Thanks SSCrazy. I ran as you suggested and now get the correct answer 2,5. G;-)

Sorry but when I ran your code on SQL Server 2014 I got 5 rows returned on both queries? 😀

Any ideas what happened?

92945 & 92949?

Thanks Steve - I've learned a new FUNCTION. Gill

I answered Primary Key won't allow nulls and Unique Key allows one null and I got it wrong - but it's showing correct in the answer?

I prefer the role I appear to have slotted into. Whereby I set up the databases (design and develop), give staff permissions ie access levels, set up audit logs...

I agree - my main inspirer, however, is a class act. These people are probably far and few between.

I'm inspired by one of my colleagues who works within our network team. There's no question ON eg SQL or PHP that I've asked him that he can't answer...