我想要与 Symfony 和 Doctrine 建立简单的多对多关系。这实际上是一个单向的一对多关联，可以通过连接表映射为 the docs indicate。我正在使用 YAML 文件通过以下代码对其进行配置:

在文件 Content.orm.yml 中:

manyToMany:
  comments:
    cascade: ["persist","remove"]
    onDelete: CASCADE
    options:
      cascade:
        remove: true
        persist: true
        #refresh: true
        #merge: true
        #detach: true
    orphanRemoval: false
    orderBy: null
    targetEntity: Comment
    joinTable:
      name: content_comments
      joinColumns:
        content_id:
          referencedColumnName: id
      inverseJoinColumns:
        comment_id:
          referencedColumnName: id
          unique: true

这会产生以下 SQL 命令:

$ php app/console doctrine:schema:update --dump-sql | grep -i "comment\|content"
CREATE TABLE comment (id INT AUTO_INCREMENT NOT NULL, text LONGTEXT NOT NULL, content_id INT NOT NULL, creation_date DATETIME NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = InnoDB;
CREATE TABLE contents (id INT AUTO_INCREMENT NOT NULL, user INT DEFAULT NULL, user_id INT NOT NULL,file VARCHAR(255) DEFAULT NULL, INDEX IDX_B4FA11778D93D649 (user), PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = InnoDB;
CREATE TABLE content_comments (content_id INT NOT NULL, comment_id INT NOT NULL, INDEX IDX_D297CC584A0A3ED (content_id), UNIQUE INDEX UNIQ_D297CC5F8697D13 (comment_id), PRIMARY KEY(content_id, comment_id)) DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = InnoDB;
ALTER TABLE contents ADD CONSTRAINT FK_B4FA11778D93D649 FOREIGN KEY (user) REFERENCES users (id);
ALTER TABLE content_comments ADD CONSTRAINT FK_D297CC584A0A3ED FOREIGN KEY (content_id) REFERENCES contents (id);
ALTER TABLE content_comments ADD CONSTRAINT FK_D297CC5F8697D13 FOREIGN KEY (comment_id) REFERENCES comment (id);

但如您所见，FOREIGN KEY 指令没有“ON DELETE CASCADE”部分，即使我尝试放置我找到的所有 YAML 注释。

因为在代码中，我试图删除一个“内容”实体以及与此代码关联的所有“评论”:

        $comments = $content->getComments();

        // Remove first the parent
        $entity_manager->remove($content);
        $entity_manager->flush();

        // Remove the childs
        foreach($comments as $comment)
        {
            $entity_manager->remove($comment);
        }

        $entity_manager->flush();

这会产生以下异常。

An exception occurred while executing 'DELETE FROM comment WHERE id = ?' with params [1]:\n\nSQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`bb2server`.`content_comments`, CONSTRAINT `FK_D297CC5F8697D13` FOREIGN KEY (`comment_id`) REFERENCES `comment` (`id`))

那么，我做错了什么？或者如何强制 Doctrine 在多对多关系中加入“ON DELETE CASCADE”？

我唯一的肮脏解决方法是删除 SQL 查询并自己重建，但我需要 Doctrine 在 schema:update 中创建查询以避免我的修补:

mysql> show create table content_comments;
+------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table            | Create Table                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| content_comments | CREATE TABLE `content_comments` (
  `content_id` int(11) NOT NULL,
  `comment_id` int(11) NOT NULL,
  PRIMARY KEY (`content_id`,`comment_id`),
  UNIQUE KEY `UNIQ_D297CC5F8697D13` (`comment_id`),
  KEY `IDX_D297CC584A0A3ED` (`content_id`),
  CONSTRAINT `FK_D297CC584A0A3ED` FOREIGN KEY (`content_id`) REFERENCES `contents` (`id`),
  CONSTRAINT `FK_D297CC5F8697D13` FOREIGN KEY (`comment_id`) REFERENCES `comment` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci |
+------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> ALTER TABLE content_comments DROP FOREIGN KEY FK_D297CC5F8697D13;
Query OK, 0 rows affected (0.04 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> ALTER TABLE content_comments ADD CONSTRAINT FK_D297CC5F8697D13 FOREIGN KEY (`content_id`) REFERENCES `contents` (`id`) ON DELETE CASCADE;
Query OK, 10 rows affected (0.07 sec)
Records: 10  Duplicates: 0  Warnings: 0

编辑:解决方法。我需要将 onDelete: CASCADE 放在 JoinColumns 下

manyToMany:
  comments:
    cascade: ["persist","remove"]
    onDelete: CASCADE
    options:
      cascade:
        remove: true
        persist: true
        #refresh: true
        #merge: true
        #detach: true
    orphanRemoval: false
    orderBy: null
    targetEntity: Comment
    joinTable:
      name: content_comments
      joinColumns:
        content_id:
          referencedColumnName: id
          onDelete: CASCADE
      inverseJoinColumns:
        comment_id:
          referencedColumnName: id
          unique: true
          onDelete: CASCADE

最佳答案

您必须像这样在“joinColumns”和“inverseJoinColumns”中添加“JoinColumn”定义:

/**
 * @var Collection|null
 * @ManyToMany(targetEntity="...")
 * @JoinTable(name="...",
 *     joinColumns={@JoinColumn(name="`...`", referencedColumnName="id", onDelete="CASCADE")},
 *     inverseJoinColumns={@JoinColumn(name="`...`", referencedColumnName="id", onDelete="CASCADE")}
 * )
 */

在那里你可以添加 onDelete 级联(数据库级别)定义

关于php - 与 Symfony 和 Doctrine 的 ON DELETE CASCADE 的多对多关系，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31830131/