Good books or sites for advanced SQL queries or puzzles?

Question

I work with SQL almost on a daily basis and want to improve my SQL skills. I am looking for online resources or books for advanced queries for real life problems. I liked Joe Celko's books and I am looking for similar resources. I am also interested in SQL puzzles but ones which solve real life business apps. I am not into brain teasers, chess, games, cards and the like of SQL problems which look overly complicated or too obscure to be useful.

I want to learn to use SQL with fewer temp tables and more sophisticated joins, subqueries.. etc.

I checked out the resources from a similar SO question but I didn't find them very useful and was hoping there are others. Celko's books mention different approaches to the same problem and I find this pretty informative and eye opening. I want more! http://stackoverflow.com/questions/550545/any-recommended-websites-for-sql-puzzles

Answer 1

I found the The SQL Cookbook pretty helpful.

Answer 2

Itzik Ben-Gan might be a guy to check out. He does like puzzles, but also real-world problems. His SQL Server 2005 books are great.

Answer 3

I loved the following book:

Inside Microsoft® SQL Server® 2008: T-SQL Querying (Paperback)