SQL and beyond
SQL is a common language implemented by most databases. While it’s a nice language it does lack some features available in some databases (which often differ from database to database). Some argue, that you shouldn’t go beyond the contrains and limitations in SQL because that removes your ability to switch to a different database. That’s just wrong (in my opinion). SQL usually allows you to do all the searches and CRUD operations you need, and by not going beyond the limitations posed by SQL you can switch your application to another database with an absolute minimum number of changes in your application - especially if you utilize the Perl DBI or the Pear DB (in PHP).