A model implementation using the repository pattern. From the article: PDO for Elegant PHP Database Access, http://www.modernphpbook.com/articles/pdo-for-elegant-php-database-access - Fig 3

UserModel.php

<?php 
class UserModel
{
    public static function getUser($id)
    {
        $repository = new UserRepository();
        return $repository->find($id);
    }
    // etc...
}