Attachments to Doctrine Jira Issue DDC-1161 - https://github.com/doctrine/doctrine2/issues/1763

11000_Content.php

<?php
namespace NCMS\Common\ContentBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
    
/**
 * @ORM\Entity
 * @ORM\Table(name="content")
 * @ORM\InheritanceType("JOINED")
 * @ORM\DiscriminatorColumn(name="class", type="string")
 * @ORM\DiscriminatorMap({
	"Page" = "NCMS\ContentType\PageBundle\Entity\Page", 
	"Article" = "NCMS\ContentType\ArticleBundle\Entity\Article", 
	})
 */
class Content { 

    /** @ORM\Id 
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue
     */
    protected $id;
	
    /** @ORM\Column(type="text")
     * @Assert\NotBlank()
     */
    protected $name;
	
	/** @ORM\Column(type="integer")
     * @Assert\NotBlank()
     */
    protected $status;


    /**
     * @ORM\OneToOne(targetEntity="Content",cascade={"none"})
     */
    protected $parent;

}

11001_Page.php

<?php

namespace NCMS\ContentType\PageBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;

/**
 * @ORM\Entity
 * @ORM\Table(name="page")
 */
class Page extends Content
{
	/** @ORM\Column(type="text") */
	protected $meta;
}