SQL is the language used by all major database systems today. SQL has been around for about 30 years, but is enjoying a real renaissance in the 21st century, thanks to the tremendous success of database-driven web sites. Whether your web site is written in PHP, ASP, Perl, ColdFusion, or any other programming language, and no matter which database system you want to use—MySQL, PostgreSQL, SQL Server, DB2, Oracle, or any of the others—one fact is almost certain: if you want to have database-driven content, you’ll need to use SQL. SQL is a simple, high-level language with tremendous power. You can perform tasks with a few lines of SQL that would take pages and pages of intricate coding to accomplish in a programming language.