A number of different abstraction layers are available for PHP, most notably the PEAR DBI, Metabase and PHPLib. The one I'm going to use in this article is named ADODB (Active Data Objects DataBase), and it's one of the most full−featured and efficient PHP abstraction libraries available today. Developed by John Lim, the library currently supports a wide variety of database systems, including MySQL, PostgreSQL, Oracle, Interbase, Microsoft SQL Server, Access, ODBC and others, and has been used in a number of well−known open−source PHP projects, including phpLens, PostNuke and Webodex
