原则 2 - ManyToMany + IN 子句

我有这个模型：

/** @Entity @Table(name="articles") */
class Article {
    /** @Id @GeneratedValue @Column(type="integer") */
    protected $id;

    /** @Column(type="string", length=100, nullable=true) */
    protected $title;

    /** @ManyToOne(targetEntity="User", inversedBy="articles") */   
    protected $author;

    /** @Column(type="datetime") */
    protected $datetime;

    /**
     * @ManyToMany(targetEntity="Game", inversedBy="articles")
     * @JoinTable(name="articles_games",
     *      joinColumns={@JoinColumn(name="article_id", referencedColumnName="id")},
     *      inverseJoinColumns={@JoinColumn(name="game_id", referencedColumnName="id")}
     *      )
     */
    protected $games;

    # Constructor
    public function __construct() {
        $this->datetime = new DateTime();
        $this->games = new \Doctrine\Common\Collections\ArrayCollection();
    }

    # ID
    public function getId() { return $this->id; }

    # TITLE
    public function setTitle($v) { $this->title = $v; }
    public function getTitle() {
        if(empty($this->title)) {
            $game = $this->getFirstGame();
            return ($game instanceof Game) ? $game->getTitle() : NULL;
        } else 
            return $this->title;
    }

    # AUTHOR
    public function setAuthor($v) { $this->author = $v; }
    public function getAuthor() { return $this->author; }

    # DATE & TIME
    public function getDateTime() { return $this->datetime; }
    public function setDateTime($v) { $this->datetime = $v; }

    # GAMES
    public function setGames($value) {
        $except_txt = 'Jedna z przesłanych wartości nie jest instancją klasy Game!';

        if(is_array($value)) {
            foreach($value as $v) {
                if($v instanceof Game) $this->games->add($v);
                else throw new Exception($except_txt);
            }
        } else {
            if($value instanceof Game) $this->games->add($value);
            else throw new Exception($except_txt);
        }
    }
    public function getGames() { return $this->games; }
}

如何使查询看起来像这样

SELECT a FROM Article a WHERE :game_id IN a.games

我有这个（$game->getId()是一个整数）

$articles = $db->createQuery("SELECT a.type FROM Article a WHERE :game_id IN a.games GROUP BY a.type")->setParameter('game_id', $game->getId())->getResult();

但它返回给我一个语法错误

[Syntax Error] line 0, col 47: Error: Expected Doctrine\ORM\Query\Lexer::T_OPEN_PARENTHESIS, got 'a'

这个问题链接自我刚刚回答的一个最近的问题 https://stackoverflow.com/a/26976090/1188035，我觉得把它放在这里也会有好处，因为它是一个更正确的解决方案：

教义IN函数需要的格式为(1, 2, 3, 4, ...)之后IN陈述。不幸的是，它并不意味着列条件可以证明成员资格。

不过，我相信您正在寻找MEMBER OF教义功能：

SELECT a FROM Article a WHERE :game_id MEMBER OF a.games

您可以将有效的 Doctrine 对象或标识符传递给game_id使用此功能。

这个例子隐藏在深处教义文档 http://doctrine-orm.readthedocs.org/en/latest/reference/dql-doctrine-query-language.html:

$query = $em->createQuery('SELECT u.id FROM CmsUser u WHERE :groupId MEMBER OF u.groups');
$query->setParameter('groupId', $group);
$ids = $query->getResult();