Doctrine2 query error in OneToMany relation - php

Question

I've got a doctrine2 problem with a MySQL database:
I have a model User and a model Documents. Each User may have 0 or n Documents. Each Document is assigned to exactly one User. My models:
User
<?php
namespace Entity;
/**
* #Entity(repositoryClass="Entity\Repository\UserRepository")
* #Table(name="user")
*/
class User extends Object
{
/**
* #Id #GeneratedValue(strategy="UUID")
* #Column(type="string", length=36)
* #var string
*/
protected $id;
/**
* #OneToMany(targetEntity="\Entity\Document", mappedBy="user")
*/
private $documents;
public function __construct($options = array())
{
$this->documents = new \Doctrine\Common\Collections\ArrayCollection;
}
}
Document
<?php
namespace Entity;
/**
* #Entity(repositoryClass="Entity\Repository\DocumentRepository")
* #Table(name="document")
*/
class Document extends Object
{
/**
* #Id #Column(type="string")
* #var string
*/
protected $id;
/**
* #ManyToOne(targetEntity="\Entity\User", inversedBy="documents")
* #JoinColumn(name="user_id", referencedColumnName="id")
* #var User
*/
private $user;
}
Now I want to get the User of a given Document ID. The SQL-query would be:
SELECT u.*
FROM `user` u
INNER JOIN `document` d ON d.user_id = u.id
WHERE d.id = 'mydocumentid'
But this does't work:
$user = $queryBuilder
->select('u.*')
->from('\\Entity\\User', 'u')
->innerJoin('\\Entity\\Document', 'd', \Doctrine\ORM\Query\Expr\Join::ON, 'd.user_id = u.id')
->where('d.id = :documentId')
->setParameter('documentId', 'mydocumentid')
->setMaxResults(1)
->getQuery()
->getSingleResult();
Also the direct query doesn't work:
$query = $em->createQuery('
SELECT
u.*
FROM
Entity\\User u
INNER JOIN
Entity\\Document d ON d.user_id = u.id
WHERE
d.id = "mydocumentid"
');
Could you please help me to get this run?
Error message
[Semantical Error] line 0, col 66 near 'd ON d.user_id': Error: Identification Variable \Entity\Document used in join path expression but was not defined before.

Answer 1

Instead of using:
->innerJoin('\\Entity\\Document', 'd', \Doctrine\ORM\Query\Expr\Join::ON, 'd.user_id = u.id')
Try using this:
->innerJoin('u.documents', 'd', \Doctrine\ORM\Query\Expr\Join::ON, 'd.user_id = u.id')
This is because Doctrine needs to know to which field in user the documents have to be joined. Knowing the field Doctrine will fetch the target entity and that way Doctine directly knows the class.