Query an inherited table via a relation table - symfony

Question

I want to achieve a pretty simple query in theory but I didn't manage to make it work: I want the number of active CVs grouped by Elo (which is an attribute in an inherited table).
The error:
[Semantical Error] line 0, col 22 near 'elo FROM MyNamespace\CvBundle\Entity\Cv':
Error: Class MyNamespace\CvBundle\Entity\Cv\Feature has no field or association named elo.
It complains about not having a field in MyNamespace\CvBundle\Entity\Cv\Feature which is true because it's the "master" table. This field is contained in the MyNamespace\CvBundle\Entity\Cv\Lol which is a table inherited from Cv\Feature
Here's the query:
// CvRepository.php
public function getStats()
{
$query = $this->createQueryBuilder('c')
->select('COUNT(f.id), f.elo')
->leftJoin('c.feature', 'f')
->groupBy('f.elo')
->where('f INSTANCE OF MyNameSpace\CvBundle\Entity\Cv\Lol')
->andWhere('c.active = :active')
->andWhere('c.expiresAt > :now')
->setParameters(array(
'now' => new \DateTime("now"),
'active' => 1,
))
->getQuery();
return $query->execute();
}
And the the table Cv:
// Cv.php
/**
* #ORM\Table(name="cv")
* #ORM\Entity(...)
*/
class Cv
{
/**
* #ORM\OneToOne(targetEntity="MyNameSpace\CvBundle\Entity\Cv\Feature", cascade={"all"})
*/
protected $feature;
}
The Feature.php
/**
* #ORM\Entity()
* #ORM\Table(name="cv_feature")
* #ORM\InheritanceType("SINGLE_TABLE")
* #ORM\DiscriminatorColumn(name="type", type="string")
* #ORM\DiscriminatorMap({"lol" = "Lol", ...})
*/
abstract class Feature
{
/**
* #ORM\OneToOne(targetEntity="MyNameSpace\CvBundle\Entity\Cv")
* #ORM\JoinColumn(name="cv_id", referencedColumnName="id", onDelete="CASCADE")
*/
private $cv;
And the Lol.php
/**
* #ORM\Entity()
*/
class Lol extends Feature
{
/**
* #var integer $elo
*
* #ORM\Column(name="elo", type="string")
*/
private $elo;
....

Answer 1

Pretty sure you will have to move $elo to your Feature class.
Your 'where instance of' will restrict the results to Lol classes but I doubt if DQl is smart enough to realize that all features will then be lol's.
You could probably change Cv to point to Lol but thats probably not what you want either.
You could also implement the group by in php.
But try this and verify it works:
abstract class Feature
{
/**
* #ORM\OneToOne(targetEntity="MyNameSpace\CvBundle\Entity\Cv")
* #ORM\JoinColumn(name="cv_id", referencedColumnName="id", onDelete="CASCADE")
*/
private $cv;
/**
* #var integer $elo
*
* #ORM\Column(name="elo", type="string")
*/
protected $elo;
You would only put getter/setters for elo on your Lol class. So it's basically hidden from it's siblings. And it's already going to be in the database table anyway. You might even be able to keep it as private and add it to Lol only so siblings would have no access to it at all. Not sure about that but I think doctrine might still hydrate it.