Symfony joining DQL expressions with "NOT IN" - php

Question

I'm using Symfony2 and i'm trying to get an array of languages not associated to a specified client.
I have a Client entity indicating the Client, ClientLanguage that has the following structure:
id_menu_language PRIMARY KEY
language the association with the Language entity
client the association with the Client entity
sequence tells the order the language should be shown (not used here)
and Language Entity.
To get an array of languages not associated to the client i want to proceed in the following way:
Get the languages that the client has already associated (and I'm getting the correct DQL in the $clientLanguagesDQL variable)
Retrieve a list of all the available languages
Exclude from that list all the languages already associated to the client (by using NOT IN (...) ).
This is the function I wrote to accomlish that:
<?php
namespace AppBundle\Repository;
use AppBundle\Entity\Client;
use Doctrine\ORM\EntityRepository;
use Doctrine\ORM\Query\Expr\Join;
class ClientRepository extends EntityRepository
{
/**
* #param $client Client to check
* #return array
*/
public function getLanguagesNotAssociatedToClient($client)
{
$qb = $this->getEntityManager()->createQueryBuilder();
$clientLanguagesDQL = $qb
->select('lang')
->from('AppBundle:Language', 'lang')
->join('AppBundle:ClientLanguage', 'languages_assoc', Join::WITH, 'languages_assoc.language = lang')
->join('AppBundle:Client', 'client', Join::WITH, 'languages_assoc.client = client')
->where('client.idClient = :client_id')
->getQuery()
->getDQL();
$languages = $qb->select('language')
->from('AppBundle:Language', 'language')
->where($qb->expr()->notIn('language', $clientLanguagesDQL))
->setParameter('client_id', $client->getIdClient())
->getQuery()
->getResult();
return $languages;
}
}
However, when I run this, Symfony complains about a : [Semantical Error] line 0, col 293 near 'lang INNER JOIN': Error: 'lang' is already defined. It also tells me that there is a QueryException, and it shows me the following query:
SELECT language
FROM AppBundle:Language lang
INNER JOIN AppBundle:ClientLanguage languages_assoc
WITH languages_assoc.language = lang
INNER JOIN AppBundle:Client client
WITH languages_assoc.client = client, AppBundle:Language language WHERE language NOT IN(
SELECT lang
FROM AppBundle:Language lang
INNER JOIN AppBundle:ClientLanguage languages_assoc
WITH languages_assoc.language = lang
INNER JOIN AppBundle:Client client
WITH languages_assoc.client = client
WHERE client.idClient = :client_id
)
And this is definitely not what I want to do. Why there appeared to be two joins with AppBundle:ClientLanguage and AppBundle:Client? I use this association only in my first subquery.
If it can help, when I run this:
$clientLanguagesDQL = $qb
->select('lang')
->from('AppBundle:Language', 'lang')
->join('AppBundle:ClientLanguage', 'languages_assoc', Join::WITH, 'languages_assoc.language = lang')
->join('AppBundle:Client', 'client', Join::WITH, 'languages_assoc.client = client')
->where('client.idClient = :client_id')
->getQuery()
->getDQL();
This is the returned DQL stored in $clientLanguageDQL:
SELECT lang
FROM AppBundle:Language lang
INNER JOIN AppBundle:ClientLanguage languages_assoc
WITH languages_assoc.language = lang
INNER JOIN AppBundle:Client client
WITH languages_assoc.client = client
WHERE client.idClient = :client_id
What's wrong with this query?

Answer 1

My mistake was very stupid, all I had to do is creating a new query builder for each query instead of reusing the first one:
$qb1 = $this->getEntityManager()->createQueryBuilder();
$clientLanguagesDQL = $qb1
->select('lang')
->from('AppBundle:Language', 'lang')
->join('AppBundle:ClientLanguage', 'languages_assoc', Join::WITH, 'languages_assoc.language = lang')
->join('AppBundle:Client', 'client', Join::WITH, 'languages_assoc.client = client')
->where('client.idClient = :client_id')
->getQuery()
->getDQL();
$qb2 = $this->getEntityManager()->createQueryBuilder();
$languages = $qb2->select('language')
->from('AppBundle:Language', 'language')
->where($qb2->expr()->notIn('language', $clientLanguagesDQL))
->setParameter('client_id', $client->getIdClient())
->getQuery()
->getResult();
return $languages;