php - 删除带有 FK 的行作为 PK + Symfony2 和 Doctrine

Question

我有一个表 items ，其中包含 item_id, item_title, ... 。我还有一个表 articles，其中包含 PK item_id(它是表 items 中的 FK)和一个字段 article_body 。我还具有从 items 到 categories 的多对多关系 (item_has_catogories)。

这是我的文章实体:

<?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;
    }
}

正如您所看到的，我的文章实体从项目实体扩展而来，我的项目实体:

<?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;
    }
}

现在我想删除一篇文章(= 一个项目)。这就是我所做的:

$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();

但我总是收到此错误:

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)

我做错了什么？

Answer 1

答案正如哈斯特所说，我没有在我的文章表中的 FK item_id 处定义“CASCADE ON DELETE”。