I think it's out of print, unfortunately, but by far the best quick intro
I've ever seen is: "The Essence of SQL: A Guide to Learning Most of SQL in
the Least Amount of Time" by David Rozenshtein.
--
Scott Ribe
scott_ribe(at)killerbytes(dot)com
http://www.killerbytes.com/
(303) 722-0567 voice