Rene, I've gotten a lot of mileage lately out of 'The PHP Anthology, Volumes I and II' by Harry Fuecks and published by SitePoint. The author demonstrates IMO fairly sophisticated usage of OOP techniques in constructing classes for MySQL, in particular. And the coding examples are robust and explained really well. As to using MySQL and building queries, Paul DuBois' MySQL, Second Edition has stood the test of time for me as a basic and advanced reference. dave