symfony2中没有数据库访问权限的模型

namespace AppBundle\Model;

class User
{
    private $name;
    private $email;

    public function getName()
    {
        return $this->name;
    }

    public function setName($name)
    {
        $this->name = $name;
    }

    public function getEmail()
    {
        return $this->email;
    }

    public function setEmail($email)
    {
        $this->email = $email;
    }
}

doctrine:
    orm:
        entity_managers:
            default:
                mappings:
                    AppBundle:
                        exclude_if: "entity.getEntityName() == 'AppBundle\\Model\\User'"

$user = new User();
$user->setName('John Doe');
$user->setEmail('john.doe@example.com');