How do you continue to improve your SQL skills?
sql-server
Solution
Find challenging questions that test your TRANSACT-SQL knowledge ... personally I enjoy Joe Celko's SQL Puzzles and Answers.
Joe Celko's SQL Puzzles and Answers http://ecx.images-amazon.com/images/I/51DTJ099P7L._SL500_BO2,204,203,200_PIsitb-dp-500-arrow,TopRight,45,-64_OU01_AA240_SH20_.jpg
Problem
How do SQL developers go about keeping up on current techniques and trends in the SQL world? Are there any blogs, books, articles, techniques, etc that are being used to keep up to date and in the know? There are a lot of opportunities out their for OO, procedural, and functional programmers to take part in a variety of open source projects, but it seems to me that the FOSS avenue is a bit more closed for SQL developers. Thoughts?