A model implementation using a data access object. From the article: PDO for Elegant PHP Database Access, http://www.modernphpbook.com/articles/pdo-for-elegant-php-database-access - Fig 2

UserModel.php

<?php 
class UserModel
{
    public static function getUser($id)
    {
        $dao = new DataAccessObject();
        return $dao->query('
            SELECT * FROM users WHERE id = ' . (int)$id
        );
    }
}