The PostgreSQL book at http://www.PostgreSQL.org/docs/awbook.html
teaches SQL. There is a nice tutorial at
+ http://w3.one.net/~jhoffman/sqltut.htm and at
http://ourworld.compuserve.com/homepages/graeme_birchall/HTM_COOK.HTM.
Another one is "Teach Yourself SQL in 21 Days, Second Edition" at
http://www.PostgreSQL.org/docs/awbook.html</A> teaches SQL.
There is a nice tutorial at <A
+HREF="http://w3.one.net/~jhoffman/sqltut.htm">
+http://w3.one.net/~jhoffman/sqltut.htm</A> and at <A
HREF="http://ourworld.compuserve.com/homepages/graeme_birchall/HTM_COOK.HTM">
http://ourworld.compuserve.com/homepages/graeme_birchall/HTM_COOK.HTM.</A><P>