Looking for an intro-to-SQL book which is PostgreSQL-friendly

All,

I'm looking for an intro-to-SQL book for teaching a class, one aimed at
folks who know *nothing* about RDBMSes, which is not based on MySQL or
MSAccess.  The ones I have on my desk are all based on one or the other,
except The Manga Guide to Databases, which I can't use in a serious class.

The PostgreSQL books I've seen all make the assumption that the reader
already knows what an RDBMS is and a little SQL.  The sole exception to
this may be Beginning Databases with PostgreSQL from Apress, but that
book is somewhat out-of-date (last edition, 2005), and teaches some bad
habits around keys.

Does anyone have other suggestions?

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com