City Query by State

CityRepository.php

<?php

namespace AppBundle\Entity;

use Doctrine\ORM\EntityRepository;

/**
 * CityRepository
 *
 * This class was generated by the Doctrine ORM. Add your own custom
 * repository methods below.
 */
class CityRepository extends EntityRepository
{

    public function findByStateId($state_id)
    {
        $query = $this->getEntityManager()->createQuery("
            SELECT c
            FROM AppBundle:City c
            LEFT JOIN c.state s
            WHERE s.id = :state_id
        ")->setParameter('state_id', $state_id);

        return $query->getArrayResult();
    }
}