How do you create ManyToOne relation within single supermapped class - php

Question

I am creating a simple CMS Bundle for my headless symfony backend and I'm trying to map Page to Page with parent and child relation(Many children to one parent) and I have this class mapped superclass to create reusable code, this is a minified sample on what I'm trying to archive:
use Doctrine\ORM\Mapping as ORM;
/**
* #ORM\MappedSuperclass()
*/
class Test
{
/**
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
protected $id;
public function getId()
{
return $this->id;
}
/**
* #ORM\ManyToOne(targetEntity="Ziebura\CMSBundle\Entity\Test")
*/
protected $parent;
public function getParent()
{
return $this->parent;
}
public function setParent($parent)
{
$this->parent = $parent;
}
}
Then I'm extending this class as a normal entity to create DB table
<?php
namespace App\Entity;
use Doctrine\ORM\Mapping as ORM;
use Ziebura\CMSBundle\Entity\Test as BaseTest;
/**
* #ORM\Table(name="test")
* #ORM\Entity(repositoryClass="App\Repository\TestRepository")
*/
class Test extends BaseTest
{
}
The issue is that I'm getting this doctrine exception
Column name `id` referenced for relation from App\Entity\Test towards Ziebura\CMSBundle\Entity\Test does not exist.
I don't quite understand why it produces this error or is the thing that I'm trying to archive impossible, I already did relations on mapped superclasses but it was 2 or more tables and not just a single on. I already tried creating $children field but it didnt worked and still produced above error. Did anyone try to create something simmilar? I couldn't find anything about this in doctrine docs, only found how to map 2 different superclasses. I suppose the easy way out would be to specify the relation in App namespace not in the Bundle but that pretty much destroys the purpose of reusable code if I'd have to declare that in every project I use the bundle. I believe in stack let's figure this out. Thanks!

Answer 1

Lets read Doctrine docs about this: https://www.doctrine-project.org/projects/doctrine-orm/en/2.6/reference/inheritance-mapping.html#inheritance-mapping
A mapped superclass is an abstract or concrete class that provides persistent entity state and mapping information for its subclasses, but which is not itself an entity. Typically, the purpose of such a mapped superclass is to define state and mapping information that is common to multiple entity classes.
...
A mapped superclass cannot be an entity, it is not query-able and persistent relationships defined by a mapped superclass must be unidirectional (with an owning side only). This means that One-To-Many associations are not possible on a mapped superclass at all.
According to this:
MappedSuperclass cannot be Entity
Cannot have One-To-Many relationship - so if you are defining ManyToOne to same class then it creates also OneToMany on same class - which, as you read above, is forbidden.

Answer 2

For some reason only changing the full entity path in BaseTest resolved app throwing the exception and it works, if anyone would face same issue try changing
/**
* #ORM\ManyToOne(targetEntity="Ziebura\CMSBundle\Entity\Test")
*/
protected $parent;
public function getParent()
{
return $this->parent;
}
public function setParent($parent)
{
$this->parent = $parent;
}
To
/**
* #ORM\ManyToOne(targetEntity="Test")
*/
protected $parent;
public function getParent()
{
return $this->parent;
}
public function setParent($parent)
{
$this->parent = $parent;
}
If someone knows why it has to be like this I'd much appreciate a comment to my answer.