FWIW, SQLObject has some logic in place which mimics some of these ideas.
In general, I think you could work out a "compiler" which generates SQL from the expression - you'd only need to define a set of special objects that build a logical representation of the expression by using the various hooks (__add__, __sub__, etc.).
You can find code to do this in sqlobject.sqlbuilder: http://svn.colorstudy.com/trunk/SQLObject/sqlobject/sqlbuilder.py -- it doesn't have any (important) dependencies on the rest of SQLObject.
-- Ian Bicking / [EMAIL PROTECTED] / http://blog.ianbicking.org _______________________________________________ DB-SIG maillist - [email protected] http://mail.python.org/mailman/listinfo/db-sig
