The demand for SQL information and training continues to grow with the need for a database behind every website capable of offering web-based information queries. SQL is the de facto standard for database retrieval, and if you need to access, update, or utilize data in a modern database management system, you will need SQL to do it. The Second Edition of Joe Celko's Trees and Hierarchies in SQL for Smarties covers two new sets of extensions over three entirely new chapters and expounds upon the changes that have occurred in SQL standards since the previous edition's publication. Benefit from mastering the challenging aspects of these database applications in SQL as taught by Joe Celko, one of the most-read SQL authors in the world.