Attempted to call an undefined method named "createQueryBuilder" - symfony

Question

i'm trying to understand how to do a QueryBuilder in a service so here is what i've done :
Create my service :
namespace OC\PlatformBundle\PurgerAdvert;
use Doctrine\ORM\EntityManager;
class PurgerAdvert
{
private $em;
public function __construct(EntityManager $em) {
$this->entityManager = $em;
}
public function purge($days)
{
$queryBuilder = $this->createQueryBuilder();
$queryBuilder->select('a')->from('OCPlatformBundle:Advert', 'a');
// get the Query from the QueryBuilder here ...
$query = $qb->getQuery();
return $result = $query->getResult();
}
}
Declare it in services.yml :
oc_platform.purger.advert:
class: OC\PlatformBundle\PurgerAdvert\PurgerAdvert
arguments: ['#doctrine.orm.entity_manager']
I remove the query because i've an error before that : "Attempted to call an undefined method named "createQueryBuilder" of class "OC\PlatformBundle\PurgerAdvert\PurgerAdvert"" I assume that i didn't call properly the entitymanager but i don't see my mistake ...
Thanks for your help :)

Answer 1

You may not want to type entityManager all the time, so a combination of both answers should work:
namespace OC\PlatformBundle\PurgerAdvert;
use Doctrine\ORM\EntityManager;
class PurgerAdvert
{
private $entityManager;
public function __construct(EntityManager $em) {
$this->entityManager = $em;
}
public function purge($days)
{
$queryBuilder = $this->entityManager->createQueryBuilder();
$queryBuilder->select('a')->from('OCPlatformBundle:Advert', 'a');
// get the Query from the QueryBuilder here ...
$query = $qb->getQuery();
return $result = $query->getResult();
}
}
Try that, I think it should work.