EntityRepository.php

    public function yourMethodName()
    {
        $builder = $this->getEntityManager()->createQueryBuilder();
        $builder->from('Module\Entity\Entity', 'entity');
        $builder->select('entity');
        $builder->leftJoin('entity.relation', 'relation');
        $builder->addSelect('relation');
        
        return $builder->getQuery()->getResult();
    }