Doctrine 2 - ORM
  1. Doctrine 2 - ORM
  2. DDC-2250

Joining Associations in Single Inheritance Scheme

    Details

    • Type: Bug Bug
    • Status: Resolved
    • Priority: Major Major
    • Resolution: Can't Fix
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: None
    • Security Level: All
    • Labels:
      None

      Description

      Let's assume the following class hierarchy:

      AbstractComment
      SpecialComment extends AbstractComment
      {
          private $specialAssociation;
      }
      RegularComment extends RegularComment
      

      Now, I'd like to write a query such as:

      SELECT c, a FROM AbstractComment c LEFT JOIN c.specialAssociation a
      

      The idea is to preload the association when selecting all comments. Now, that association is only present on a sub-class of the queried class, but since it is a single table inheritance, Doctrine should be able to join it for those entities where it is present.

      At the moment unfortunately, Doctrine shows an error that the association does not exist on the AbstractComment class. Also, there is no real alternative to this except moving the collection to the base class even if it does not belong there.

        Activity

        Hide
        Benjamin Eberlei added a comment -

        DQL has strict typing with regard to inheritance, this type of query is not possible.

        Show
        Benjamin Eberlei added a comment - DQL has strict typing with regard to inheritance, this type of query is not possible.
        Hide
        Johannes Schmitt added a comment -

        A too bad. I guess the code around inheritance is already quite complex that it does not make sense to add an exception for this case.

        Do you think it would somehow (maybe manually) be possible to load collections in a batch operation? For example, something like this:

        $batch = array();
        foreach ($comments as $comment) {
            if ($comment instanceof SpecialComment) {
                $batch[] = $comment->getSpecialAssociation();
            }
        }
        
        $this->em->batchLoad($batch);
        
        Show
        Johannes Schmitt added a comment - A too bad. I guess the code around inheritance is already quite complex that it does not make sense to add an exception for this case. Do you think it would somehow (maybe manually) be possible to load collections in a batch operation? For example, something like this: $batch = array(); foreach ($comments as $comment) { if ($comment instanceof SpecialComment) { $batch[] = $comment->getSpecialAssociation(); } } $ this ->em->batchLoad($batch);

          People

          • Assignee:
            Benjamin Eberlei
            Reporter:
            Johannes Schmitt
          • Votes:
            0 Vote for this issue
            Watchers:
            2 Start watching this issue

            Dates

            • Created:
              Updated:
              Resolved: