mysql - Symfony/主义:OneToMany插入结果为空ID

我有两个实体，我试图将OneToMany / ManyToOne关系应用于（一个游戏具有很多GameContent）。

游戏

/**
 * @ORM\OneToMany(targetEntity="GameContent", mappedBy="game")
 */
private $contents;

public function __construct()
{
    $this->contents = new ArrayCollection();
}

public function getContents()
{
    return $this->contents;
}

游戏内容

/**
 * @ORM\ManyToOne(targetEntity="Game", inversedBy="contents")
 */
private $game;

下面的代码将两条记录插入各自的表中：

$game = $form->getData();
$content = new GameContent();
$content->setType('some type');
$game->getContents()->add($content);

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

但是，GameContent的game_id被插入为null：

INSERT INTO game_content (type, game_id) VALUES (?, ?)
Parameters: { 1: 'some type', 2: null }

我也尝试过：


更改persist()的顺序
通过执行$game->getContents()->add($content)用$game->addContents($content)替换$this->contents[] = $content;
删除persist($content)并在游戏实体上具有cascade={"persist"}。


为什么将game_id插入为null？



我当前的解决方法是：

$em = $this->getDoctrine()->getManager();

$game = $form->getData();
$em->persist($game);

$content = new GameContent();
$content->setType('some type');
$content->setGame($game);
$em->persist($content);

$em->flush();

最佳答案

您有2个解决方案：

坚持控制中的孩子

没有cascade={"persist"}

$em = $this->getDoctrine()->getManager();

// Get data
$game = $form->getData();

// Create new GameContent and hydrate
$content = new GameContent();
$content->setType('some type');

// Associate Game <> GameContent
$content->setGame($game);

// Persist GameContent
$em->persist($content);

// Persist Game and commit
$em->persist($game);
$em->flush();

坚持儿童梯级

与OneToMany关系中的cascade={"persist"}。

添加setGame()函数，以强制关联：

$game->addContent($this);

并删除坚持：

$em = $this->getDoctrine()->getManager();

// Get data
$game = $form->getData();

// Create new GameContent and hydrate
$content = new GameContent();
$content->setType('some type');

// Associate Game <> GameContent
$content->setGame($game);

// Persist Game and commit
$em->persist($game);
$em->flush();

我认为错误也是由于坚持游戏的定位。