Doctrine2关联映射与条件

Question

is it possible to have association mapping with conditions in Doctrine 2.4? I have entities Article and Comment. Comments needs to be approved by admin. Approval status of comment is stored in boolean field "approved.

Now I have @OneToMany association mapping to comments in entity Article. It maps all the comments. But I would like to map only approved comments.

Something like

@ORM\OneToMany(targetEntity="Comment", where="approved=true", mappedBy="article")

would be very helpful. Unfortunately AFAIK there is no such thing as where condition in mapping, so I tried to solve my problem with inheritance - I created two subclasses of class Comment. Now I have ApprovedComment and NotApprovedComment and SINGLE_TABLE inheritance mapping.

 @ORM\InheritanceType("SINGLE_TABLE")
 @ORM\DiscriminatorColumn(name="approved", type="integer")
 @ORM\DiscriminatorMap({1 = "ApprovedComment", 0 = "NotApprovedComment"})

Problem is, since "approved" column is discriminator, I cannot use it as field in entity Comment anymore.

Answer 1

You can use the Criteria API to filter the collection:

<?php

use Doctrine\Common\Collections\Criteria;

class Article
{

    /**
     * @ORM\OneToMany(targetEntity="Comment", mappedBy="article")
     */
    protected $comments;

    public function getComments($showPending = false)
    {
        $criteria = Criteria::create();
        if ($showPending !== true) {
            $criteria->where(Criteria::expr()->eq('approved', true));
        }
        return $this->comments->matching($criteria);
    }

}

This is especially nice, because Doctrine is smart enough to only go to the database if the collection hasn't already been loaded.