ezSQL is a class that makes it ridiculously easy to use mySQL, Oracle8, SQLite (PHP), within your PHP script. Includes lots of examples making it very easy to understand how to work with databases.

MySQLDumper is a backup programm for MySQL-Databases, written in PHP and Perl. You can dump your data into a backup file and if needed, restore it. Especially on shared hostings without access to shell-commands, MySQLDumper is a sensefull option.