Symfony join

public function test() {
        $query = $this->getEntityManager()->createQueryBuilder()
                ->select('s','su','rv')
                ->from(Project::class, 's')
                ->leftJoin('s.sub_projects', 'su')
                ->leftJoin('su.reports_validation', 'rv')

                ->getQuery()
        ;
        
        return $query->getResult();
    }

2/

/**
     * get sub projects
     * 
     * @param Project $project
     * 
     * @return array
     */
    public function getSubProjects(Project $project): array {
        $query = $this->getEntityManager()->createQueryBuilder()
                ->select('s.id', 's.name')
                ->from(SubProject::class, 's')
                ->where('s.project = :project')->setParameter('project', $project)
                ->getQuery()
        ;
        try {
            return $query->getResult();
        } catch (\Doctrine\ORM\NoResultException $e) {
            return [];
        }
    }