If you want to try to keep your application standards compliant try this application: Mimer Validator
It lets you test any SQL query for SQL-92 and SQL-99 compliance. If you do this consistently, you won't make your application dependent on a certain database.
The guy that wrote this application is on the SQL-200n standard committee (you can read about it if you go to www.mimer.com
), which lends it some credibility.