SovBundle/Repository/TreeRepositoryQueryTrait.php

<?php

namespace Lc\SovBundle\Repository;

use Lc\SovBundle\Doctrine\EntityInterface;

trait TreeRepositoryQueryTrait
{
    public function filterIsParent()
    {
        return $this->andWhere('.parent is NULL');
    }

    public function filterIsChildren()
    {
        return $this->andWhere('.parent is NOT NULL');
    }

    public function filterByParent(EntityInterface $parent)
    {
        return $this->andWhere('.parent = :parent')->setParameter('parent', $parent);
    }

}