nullable self reference with composite keys using doctrine - php

Question

I've got a problem with Doctrine ORM 2.5. The issue happens when I try to load instances of an entity that has an optional ManyToOne reference to itself using part of its primary key as a part of the foreign key.
The entity looks like the following:
class Category
{
/**
* #ORM\Id
* #ORM\ManyToOne(targetEntity="Client")
* #ORM\JoinColumn(name="client_id", referencedColumnName="client_id"))
* #var Client
*/
protected $client;
/**
* #ORM\Id
* #ORM\Column(type="string")
* #var string
*/
protected $category_id;
/**
* #ORM\ManyToOne(targetEntity="Category")
* #ORM\JoinColumns({
* #ORM\JoinColumn(name="parent_id", referencedColumnName="category_id", nullable=true),
* #ORM\JoinColumn(name="client_id", referencedColumnName="client_id", nullable=false)
* })
* #var Category
*/
protected $parent;
/**
* #ORM\Column(type="translated")
* #SAP\Mapping(fieldName="name")
* #var string
*/
protected $name;
}
As you can see, every child of a category must have the same client_id as its parent.
The problem seems to be that Doctrine expects the parent to exists of the foreigen key isnt empfy ( = at least one field has a non-null value). Thats obviously always true since the FK contains a part of the PK.
Is there a way to tell Doctrine that it shouldn't try to load the parent if parent_id is null?
The only alternatives I see are changing the schema by either using an artifical auto generated pk or adding a new column for the parent_client_id and make sure it equals the client_id in PHP-land.
Is there a better way?

Answer 1

It seems like this is a bug as reported here: https://github.com/doctrine/orm/issues/4384
From the comments on that issue setting fetch="EAGER" resolves the doctrine Missing value for primary key error. Not really a great solution, but it may work for you depending on your use case.