Symfony / Doctrine：OneToMany插入导致null id

Question

我有两个实体，我正在尝试应用OneToMany / ManyToOne关系（一个游戏有很多GameContent）。

游戏

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

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

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

GameContent

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

以下代码将两个记录都插入到各自的表中：

$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作为null插入：

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

我也尝试过：

• 改变persist()的顺序
• 用$game->getContents()->add($content)用$game->addContents($content)取代$this->contents[] = $content;
• 删除persist($content)并在游戏实体上使用cascade={"persist"}。

为什么game_id被插入为null？

---

我目前的解决方法是：

$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();

Answer 1

你有2个解决方案：

把孩子留在控制器里

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();

坚持级联的孩子

与cascade={"persist"}在OneToMany关系。

添加setGame()函数，强制关联：

$game->addContent($this);

并删除持久性：

$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持久性在游戏中的定位。

Answer 2

除了接受的答案之外，我的下一步是创建一个表单来处理GameContent数据，这导致了进一步的更改和一些简化的逻辑。

我现在在setGame() Game::addContent()，所以我在$game->addContent($this);删除了GameContent::setGame()。

游戏

/**
 * @var ArrayCollection
 * @ORM\OneToMany(targetEntity="GameContent", mappedBy="game", cascade={"persist"})
 */
private $contents;

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

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

public function addContent(GameContent $content)
{
    $this->contents->add($content);
    $content->setGame($this);

    return $this;
}

public function removeContent(GameContent $content)
{
    $this->contents->removeElement($content);

    return $this;
}

GameContent

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

public function setGame(Game $game)
{
    $this->game = $game;

    return $this;
}

/**
 * @return Game
 */
public function getGame()
{
    return $this->game;
}

真实的表单处理逻辑将如下所示：

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

更多信息请访问：http://symfony.com/doc/2.8/form/form_collections.html（参见Doctrine：级联关系并保存“反向”方面）。