$qb = $this->createQueryBuilder('p')
            ->innerJoin('p.ProductCategories', 'pct')
            ->addSelect('SUM(CASE WHEN pct.Category IN (:category) THEN 1 ELSE 0 END) AS HIDDEN category_count')
            ->having('2 = category_count')
            ->setMaxResults(1)
            ->groupBy('p.id')
            ->setParameter('category', array(126, $c_id));