SQL for item count at a given classmark

I'm trying to find out how many items we have in stock in the classmark range 600 - 699. I have run what I think the sql should be, but I am getting far fewer results than I would expect.

As my sql leaves a lot to be desired, wondered if someone could help me work it out? Thanks

count for a given classmark

Can you post the SQL you have written? It might only need a tweak or the reason for the lower number might be explained.

Also have you looked at using Talis Decisions?

Thanks

Brian Crampton
Developer, Talis