Doctrine2 findBy relationship object triggers string conversion error

Say I have two entities in Doctrine2 that are related to each other, Models\User and Models\Comment. If I do this in Doctrine 2.0.0...

<?php
// $em instanceof EntityManager, $user instanceof Models\User
$comments = $em->getRepository('Models\Comment')
    ->findBy(array('user' => $user, 'public' => true));

...I get a PHP error:

Severity: Notice

Message: Object of class Models\User to string conversion

Filename: DBAL/Connection.php

Line Number: 574

This shouldn't开发者_C百科 happen, right? If I use the QueryBuilder and setParameter('user', $user) it works as expected.

Query by relationship is allowed, but you have to pass the Identifier in there. Query by object is not yet supported and will only make it into 2.1.

<?php
// $em instanceof EntityManager, $user instanceof Models\User
$comments = $em->getRepository('Models\Comment')
->findBy(array('user' => $user->getId(), 'public' => true));

For symfony 4.1 this code worked for me.

$comments = $this->getDoctrine()
                ->getRepository(Models\Comment::class)
                ->findBy(
                ['user' => $user->getId(), 'public' => true]
);

Unfortunately, I don't think query by relationships is supported directly via repository objects.

In this case, you are probably best to write a custom repository class with a findByUser method.

<?php

namespace App\Domain\Repository;

use Doctrine\ORM\EntityRepository,
    App\Domain\Entity\User;

class CommentRepository extends EntityRepository
{

    public function findByUser(User $user)
    {
        // add QueryBuilder code here
    }

}

Don't forget to update your Comment entity to use the custom repository:

<?php

namespace App\Domain\Entity;


/** 
 * @Entity(repositoryClass="App\Domain\Repository\CommentRepository")
 */
class Comment 
{

    // entity definition

}