Advanced OOP With SPL In PHP 5

<?php
    /**
     * PostgreSQL implementer for IDataBaseBindings.
     *
     * Implements all members indicated by the interface and
     * optimizes queries for the PostgreSQL database.
     *
     * @author      Kevin McArthur
     * @depends     UnbufferedAssociativeResultSet, IDataBaseBindings
     * @implements  IDataBaseBindings
     */
    class PostgreSQL implements IDataBaseBindings
    {
        public function __construct() {
            // Create Database Connections
        }
 
        /**
         * getCustomerDetails
         *
         * Gets customer data from userDetails specified by userid
         *
         * @see IDatabaseBindings
         */
        public function getCustomerDetails($userid)
        {
            $queryResult = pg_query('select * from userDetails where userid = '. $userid . ';');
            return new UnbufferedAssociativeResultSet($queryResult);
        }
 
        public function __destruct()
        {
            // Destroy Database Connections
        }
    }
?>