groupByを保持する必要がある場合:
$query = $repository->createQueryBuilder('t')
$query->select('COUNT(t.katId)', 't.hotel', 't.title', 't.desc', 'picture', 'MIN(t.price) AS price');
$query->from(ENTITY STRING, 't', 't.hotel'); //here defined your array result key
$query->where('t.visible = (:visible)')->setParameter('visible', 1);
$query->groupBy('t.hotel');
$query->setMaxResults(10);
echo $query->getQuery()->getScalarResult();
exit();
編集:新しい編集は機能しますか?