<p>Joe Celko challenges you with his trickiest puzzles and then helps you conquer them with a variety of solutions and explanations. The puzzles are a compilation from Joe's columns in <i>DBMS</i> and <i>Database Programming & Design</i> magazines. They include new, never-before-published puzzles plus new solutions and extra background for previously published puzzles. In his usual entertaining and informative style, Joe demonstrates the thought processes that are involved in attacking a problem from an SQL perspective. Through the practical, enjoyable puzzles, he introduces immediately useful new techniques and applications for SQL programming, and shows the database programmer how to write and use non-procedural programs.