Doctrine2 get object without relations

Question

An user has one role. A role has zero or many users.

I would like to find roles without users.

I need to have this query without using IN or NOT IN

Answer 1

You can find roles that don't have any users by using a count query

$qb = $this->createQueryBuilder('role');
$qb ->addSelect('COUNT(users.id) AS total_users')
    ->leftJoin('role.users', 'users')
    ->groupBy('role.id')
    ->having('total_users = 0')
    ->getQuery()->getResult();