Remove row with FK as PK + Symfony2 and Doctrine - php

Question

I have a table items with item_id, item_title, ... . I also have a table articles with a PK item_id that is a FK from the table items and a field article_body. I also have a many to many relationship from items to categories (item_has_catogories).
This is my Article Entity:
<?php
namespace Dxsolutions\DxsolutionsBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
/**
* Item
*
* #ORM\Table(name="articles")
* #ORM\Entity
*/
class Article extends Item
{
/**
* #var string
*
* #ORM\Column(name="article_body", type="text")
*/
protected $body;
/**
* Set body
*
* #param string $body
* #return Article
*/
public function setBody($body)
{
$this->body = $body;
return $this;
}
/**
* Get body
*
* #return string
*/
public function getBody()
{
return $this->body;
}
}
As you can see my Article Entity extends from the Item Entity, my Item Entity:
<?php
namespace Dxsolutions\DxsolutionsBundle\Entity;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\ORM\Mapping as ORM;
/**
* Item
*
* #ORM\Table(name="items")
* #ORM\Entity
* #ORM\InheritanceType("JOINED")
* #ORM\DiscriminatorColumn(name="item_type", type="string")
* #ORM\DiscriminatorMap({"ITEM"="Item", "ARTICLE"="Article"})
*/
class Item
{
/**
* #var integer
*
* #ORM\Column(name="item_id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="item_title", type="string", length=255)
*/
private $title;
/**
* #var \DateTime
*
* #ORM\Column(name="item_created", type="datetimetz")
*/
private $created;
/**
* #var \DateTime
*
* #ORM\Column(name="item_modified", type="datetimetz")
*/
private $updated;
/**
* #var \DateTime
*
* #ORM\Column(name="item_deleted", type="datetimetz")
*/
private $deleted;
/**
* #var \Doctrine\Common\Collections\ArrayCollection
*
* #ORM\ManyToMany(targetEntity="Category", inversedBy="items")
* #ORM\JoinTable(name="items_has_categories",
* joinColumns={#ORM\JoinColumn(name="item_id", referencedColumnName="item_id")},
* inverseJoinColumns={#ORM\JoinColumn(name="category_id", referencedColumnName="category_id")}
* )
*/
protected $categories;
/**
* Constructor has to create Doctrine ArrayCollections
*/
public function __construct()
{
$this->categories = new ArrayCollection();
}
/**
* Get id
*
* #return integer
*/
public function getId()
{
return $this->id;
}
/**
* Set title
*
* #param string $title
* #return Item
*/
public function setTitle($title)
{
$this->title = $title;
return $this;
}
/**
* Get title
*
* #return string
*/
public function getTitle()
{
return $this->title;
}
/**
* Set created
*
* #param \DateTime $created
* #return Item
*/
public function setCreated($created)
{
$this->created = $created;
return $this;
}
/**
* Get created
*
* #return \DateTime
*/
public function getCreated()
{
return $this->created;
}
/**
* Set updated
*
* #param \DateTime $updated
* #return Item
*/
public function setUpdated($updated)
{
$this->updated = $updated;
return $this;
}
/**
* Get updated
*
* #return \DateTime
*/
public function getUpdated()
{
return $this->updated;
}
/**
* Set deleted
*
* #param \DateTime $deleted
* #return Item
*/
public function setDeleted($deleted)
{
$this->deleted = $deleted;
return $this;
}
/**
* Get deleted
*
* #return \DateTime
*/
public function getDeleted()
{
return $this->deleted;
}
/**
* Set category
*
* #param Category $category
*/
public function setCategories(Category $category)
{
$this->categories->add($category);
}
/**
* Get categories
*
* #return \Doctrine\Common\Collections\ArrayCollection
*/
public function getCategories()
{
return $this->categories;
}
}
Now I would like to delete an article (= an item).
This is what I do :
$em = $this->getDoctrine()->getManager();
$article = $em->getRepository('DxSolutionsBundle:Article')->find($id);
foreach($article->getCategories() as $c) {
$article->getCategories()->removeElement($c);
$em->flush();
}
$em->remove($article);
$em->flush();
But I always get this error:
An exception occurred while executing 'DELETE FROM items WHERE item_id = ?' with params [4]:
SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`dx-solutions`.`articles`, CONSTRAINT `fk_articles_items1` FOREIGN KEY (`item_id`) REFERENCES `items` (`item_id`) ON DELETE NO ACTION ON UPDATE NO ACTION)
What am I doing wrong?

Answer 1

The answer was as Hast said that I didn't defined 'CASCADE ON DELETE' at my FK item_id in my article table.