条件性地连接Doctrine2上的表

Question

I seeked for an answer but anything in my particular case. I need to join contintionnally table with Doctrine 2, depends on value of a field I have to join on two different foreign keys, here my code :

$qb = $this->entityManager->createQueryBuilder();
    $qb ->select('s')
        ->from('AppBundle:MyTable', 's')
        ->join('s.firstJoin', 'o')
        ->join('s.secondJoin', 'd')
        ->join('AppBundle:joinedView', 'view', Join::WITH,
            "(CASE WHEN (d.secondJoinFK = 3) 
            THEN view.did = d.secondJoinFK 
            WHEN (d.secondJoinFK = 2) 
            THEN view.dvid = d.secondJoinFK END)")
        ->addSelect('d')
        ->where('s.endDate IS NULL');

However, with this request, Symfony tells me : [Syntax Error] line 0, col 203: Error: Expected Doctrine\ORM\Query\Lexer::T_ELSE, got '='

Moreover, I cannot use native query because I use PagerFanta for rendering template, and PagerFanta needs to have a ORM\Query on input and not ORM\NativeQuery or other.

Unfortunately, I do not have choice and must implement this request with these prerequisites.

Thanks by advance for your help,

Answer 1

It is not possible to do the something like conditional join. You always need to join both tables and specify different join condition.

You can do something like this:

        ->join('AppBundle:joinedView', 'view1', Join::WITH,
        "view1.did = 3") 
        ->join('AppBundle:joinedView', 'view2', Join::WITH,
        "view2.dvid = 2")

but honestly I am not sure what are you trying to achieve. Joining tables without a condition which uses some joining column seems a bit pointless.