It's the process of attempting to resolve the question that is of interest to the interviewer not the answer.You wouldn't believe how hard it can be to lead someone to using the internet to solve a mystery error message or problem, for example.

Some typical sql problems I've been asked are:-

ALL the different ways to eliminate duplicate data in a table

How many ways to get data into SQL Server

I think basing some questions around the cv is important to establish clear experience, it's quite possible to infer skills which are not actually there, for instance I'm looking at 2005 Analysis services ( I did a lot of 2k years ago ) I could list this on my cv, but I don't have any real production experience of it - questions could establish this.