Symfony3學說單表無罪SQLSTATE [23000]：完整性約束違規

Question

我是Symfony的新手，我正在嘗試做一個簡單的Blog。我有我的數據庫中的用戶作爲評論的作者和兩種類型的評論 - PostComment和ReplyComment，它們都擴展了抽象類的評論。我想評論保存到數據庫，但我堅持了這個錯誤：

發生異常而執行「INSERT INTO評論（文字， AUTHOR_ID，POST_ID，comment_type）VALUES（，，？？？ ？）」使用參數 [ 「Lorem存有」，1，1， 「post_comment」]：

SQLSTATE [23000]：完整性約束違規：1452不能添加或 更新子行，外鍵約束失敗 （blog_symfony。comment，CONSTRAINT FK_9474526CDB1174D2 FOREIGN KEY（post_comment_id）參考文獻comment（id））

這是抽象的註釋類別：

use Doctrine\ORM\Mapping as ORM; 

/** 
* @ORM\Entity() 
* @ORM\Table(name="comment") 
* @ORM\InheritanceType("SINGLE_TABLE") 
* @ORM\DiscriminatorColumn(name="comment_type", type="string") 
* @ORM\DiscriminatorMap({"post_comment" = "PostComment", "reply_comment" = "ReplyComment"}) 
*/ 
abstract class Comment 
{ 

    /** 
    * @ORM\Id 
    * @ORM\GeneratedValue(strategy="AUTO") 
    * @ORM\Column(type="integer") 
    */ 
    protected $id; 

    /** 
    * @ORM\ManyToOne(targetEntity="AppBundle\Entity\User", inversedBy="userComments") 
    */ 
    protected $author; 

    /** 
    * @ORM\Column(type="string") 
    */ 
    protected $text; 

    /** 
    * @return integer $id 
    */ 
    public function getId() 
    { 
     return $this->id; 
    } 

    /** 
    * @return string $author 
    */ 
    public function getAuthor() 
    { 
     return $this->author; 
    } 

    /** 
    * @param string $author 
    */ 
    public function setAuthor($author) 
    { 
     $this->author = $author; 
    } 

    /** 
    * @return string $text 
    */ 
    public function getText() 
    { 
     return $this->text; 
    } 

    /** 
    * @param string $text 
    */ 
    public function setText($text) 
    { 
     $this->text = $text; 
    } 
} 

這是一個張貼評論類

use Doctrine\ORM\Mapping as ORM; 

/** 
* @ORM\Entity(repositoryClass="AppBundle\Repository\PostCommentRepository") 
*/ 
class PostComment extends Comment 
{ 
    /** 
    * @ORM\ManyToOne(targetEntity="AppBundle\Entity\Post", inversedBy="comments") 
    * @ORM\JoinColumn(nullable=true, onDelete="SET NULL") 
    */ 
    private $post; 

    /** 
    * @ORM\OneToMany(targetEntity="AppBundle\Entity\ReplyComment", mappedBy="postComment", cascade={"remove"}, orphanRemoval=true) 
    * @ORM\OrderBy({"id"="DESC"}) 
    */ 

    private $replyComments; 

    /** 
    * @return replyComment[] reply comments 
    */ 
    public function getReplyComments() 
    { 
     return $this->replyComments; 
    } 

    /** 
    * @param replyComment[] reply comments 
    */ 
    public function setReplyComments($replyComments) 
    { 
     $this->replyComments = $replyComments; 
    } 

    /** 
    * @return Post post 
    */ 
    public function getPost() 
    { 
     return $this->post; 
    } 

    /** 
    * @param Post post 
    */ 
    public function setPost($post) 
    { 
     $this->post = $post; 
    } 
} 

最後這是在控制器運行過程中出現的邏輯

代碼

if ($postCommentForm->isSubmitted() && $postCommentForm->isValid()) 
     { 
      /** @var PostComment $comment */ 
      $comment = $postCommentForm->getData(); 
      $comment->setPost($post); 

      $author = $this->getDoctrine()->getRepository('AppBundle:User')->findOneBy([ 
       'email' => $comment->getAuthor() 
      ]); 

      $comment->setAuthor($author); 

      $em = $this->getDoctrine()->getManager(); 
      $em->persist($comment); 
      $em->flush(); 

      return $this->redirectToRoute("single_post", [ 
       'id' => $post->getId() 
      ]); 
     } 

Answer 1

At首先你的基類不需要抽象。相反，你必須插入此標註類以上，這樣的學說會得到它：

@MappedSuperclass() 

remove從基礎機構的所有其他學說的註釋，它們都屬於實體類。

use Doctrine\ORM\Mapping as ORM; 

/** 
*@MappedSuperclass() 
*/ 
class Comment 
{ 

和實體有其他註釋：

use Doctrine\ORM\Mapping as ORM; 

/** 
* @ORM\Entity(repositoryClass="AppBundle\Repository\PostCommentRepository") 
* @ORM\Table(name="comment") 
*/ 
class PostComment extends Comment 
{ 

這應該有助於