News使用一对多的自引用方法相互关联(一个消息是父消息,可以有多个子消息)。更重要的是 each与和News具有正常的(非自引用的)一对一关系。当我运行简单的 DQL 时:EventGallerySELECT n FROM App\Entity\News n WHERE n.parent = :id然后通过设置getResults默认值的方法对结果进行水合HYDRATION_OBJECT,在方法内部的某处进行额外的查询getResults。SELECT t0.* FROM event t0 WHERE t0.news_id = 2 AND ((t0.deleted_at IS NULL));SELECT t0.* FROM gallery t0 WHERE t0.news_id = 2 AND ((t0.deleted_at IS NULL));SELECT t0.* FROM event t0 WHERE t0.news_id = 1 AND ((t0.deleted_at IS NULL));SELECT t0.* FROM gallery t0 WHERE t0.news_id = 1 AND ((t0.deleted_at IS NULL));第一次查询选择的新闻的孩子在哪里和在哪里news_id = 1。news_id = 2News也没有自引用的一对多关系(我在这里忽略了它们),但是 hydration 没有对它们进行额外的查询。parent仅当语句中涉及关系时才会出现此问题where。如何重现// news Entity/** * @ORM\Entity(repositoryClass="App\Repository\NewsRepository") * @ORM\Table(uniqueConstraints={@UniqueConstraint(name="news_slug_deleted", columns={"slug","deleted_at"})}) *class News { use SoftDeleteableEntity; /** * @ORM\Id() * @ORM\GeneratedValue() * @ORM\Column(type="integer") */ private $id; /** * @ORM\Column(type="string", length=255) */ private $title; /** * @Gedmo\Slug(fields={"title"}) * @ORM\Column(length=128) */ private $slug;/** * @ORM\OneToOne(targetEntity="App\Entity\Gallery", mappedBy="news", cascade={"persist", "remove"}, orphanRemoval=true) * * @var Gallery */ private $gallery; /** * @ORM\OneToOne(targetEntity="App\Entity\Event", mappedBy="news", cascade={"persist", "remove"}, orphanRemoval=true) * * @var Event */ private $event; /** * One News has Many News. * @ORM\OneToMany(targetEntity="News", mappedBy="parent") */ private $children; /** * Many News have One News. * @ORM\ManyToOne(targetEntity="News", inversedBy="children") * @ORM\JoinColumn(name="parent_id", referencedColumnName="id", nullable=true) */ private $parent;}
1 回答

慕娘9325324
TA贡献1783条经验 获得超4个赞
您在该实体中有几个反向 OneToOne 关系。
反向 OneToOne 关系不能被 Doctrine 延迟加载,并且很容易成为性能问题。
如果您真的需要将这些关系映射到反面(而不仅仅是在拥有方),请确保明确地进行适当的连接,或者将这些关联标记为以便FETCH=EAGERDoctrine 为您进行连接。
例如,避免可怕的“n+1”问题的查询是:
SELECT n, g, e
FROM App\Entity\News n
LEFT JOIN n.gallery g
LEFT JOIN n.event e
WHERE n.parent = :id
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