Symfony主义一对多查询生成器

Question

I have one to many releationship between institute and institute courses.

class Institutes {
  /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;
    /**
     * @ORM\OneToMany(targetEntity="PNC\InstitutesBundle\Entity\InstitutesCourses", mappedBy="institute", cascade={"all"})
     * */
    protected $inst;
}

class InstitutesCourses {
    /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;
    /**
     * @ORM\ManyToOne(targetEntity="PNC\InstitutesBundle\Entity\Institutes", inversedBy="inst")
     * @ORM\JoinColumn(name="institute_id", referencedColumnName="id")
     */
    protected $institute;
    /**
     * @ORM\ManyToOne(targetEntity="PNC\CoursesBundle\Entity\Courses", inversedBy="instituteCourses")
     * @ORM\JoinColumn(name="course_id", referencedColumnName="id")
     */
    protected $course;
}

I want to fetch all courses assign to one courses. each institute is owned by a user. I have wrote this psql query that is working well

SELECT ic.*
FROM institutes_courses ic
RIGHT JOIN institutes i ON i.id = ic.institute_id
WHERE i.user_id = 26;

 id  | institute_id | course_id |
-----+--------------+-----------+
 389 |           21 |        51 |
 390 |           21 |        53 |
 391 |           21 |        52 |

and translated into doctinre querybuilder like this;

$repository = $em->getRepository('PNCInstitutesBundle:InstitutesCourses');

            $query= $repository->createQueryBuilder('ic')
                ->select('ic')
                ->from('PNCInstitutesBundle:InstitutesCourses', 'ic')
                ->orderBy('ic.id', 'ASC')
                 // THE FOLLOWING LINE IS CRITICAL:
                ->JOIN('PNCInstitutesBundle:Institutes', 'i', 'WITH' ,'i.id=ic.institute')
                ->where('i.user = :user')
                ->setParameter('user', $this->getUser()->getId())
                ->getQuery();

and it says that,

[Semantical Error] line 0, col 170 near 'ic INNER JOIN': Error: 'ic' is already defined.

new to symfony2 doctrine, cant figure out what's wrong.

Answer 1

if you have a look at the source code of createQueryBuilder you'll see the following:

public function createQueryBuilder($alias, $indexBy = null)
{
    return $this->_em->createQueryBuilder()
        ->select($alias)
        ->from($this->_entityName, $alias, $indexBy);
}

Which means you should not do the following in your code.

->select('ic')
->from('PNCInstitutesBundle:InstitutesCourses', 'ic')

Just drop that lines and it should be ok. Repository already did it for you.

Answer 2

Try this:

(EDIT)

$repository = $em->getRepository('PNCInstitutesBundle:InstitutesCourses');

$query= $repository->createQueryBuilder('ic')
     ->leftJoin('ic.institute', 'i')
     ->where('i.user = :user')
     ->setParameter('user', $this->getUser()->getId())
     ->orderBy('ic.id', 'ASC')
     ->getQuery();

$results = $query->getResult();