Below is how to set up a PDO connection to a MySQL database.
<?php define('DATABASE','db_name'); define('DATABASE_USER','db_user'); define('DATABASE_PASSWORD','db_password'); try { $db = new PDO('mysql:host=localhost;dbname='.DATABASE, DATABASE_USER, DATABASE_PASSWORD,array( PDO::ATTR_PERSISTENT => true )); } catch (PDOException $e) { print "Error!: " . $e->getMessage() . "<br/>"; die(); } ?>