原则2 doc示例中的拥有侧和反向侧是什么 [英] What is the owning side and inverse side in the doctrine 2 doc example

问题描述

在关联映射的此页面上，很多部分有一个示例。但是我不知道哪个实体（组或用户）是所有者。

On this page of association mapping, there's an example in the manytomany section. But I don't understand which entity (group or user) is the owning side.

http://docs.doctrine-project.org/en/2.0.x/reference/association-mapping.html#many对多双向

我也将代码放在这里

<?php
/** @Entity */
class User
{
    // ...

    /**
     * @ManyToMany(targetEntity="Group", inversedBy="users")
     * @JoinTable(name="users_groups")
     */
    private $groups;

    public function __construct() {
        $this->groups = new \Doctrine\Common\Collections\ArrayCollection();
    }

    // ...
}

/** @Entity */
class Group
{
    // ...
    /**
     * @ManyToMany(targetEntity="User", mappedBy="groups")
     */
    private $users;

    public function __construct() {
        $this->users = new \Doctrine\Common\Collections\ArrayCollection();
    }

    // ...
}

我是否像这样阅读此注释：
用户被映射按组划分，所以组是进行连接管理的实体，因此是拥有方？

Do I read this annotation like this: User is mappedBy groups so group is the entity that does the connection management, thus the owning side?

也，我已经在文档中阅读了以下内容：

Also, I've read this in the docs:

For ManyToMany bidirectional relationships either side may be the owning side (the side  that defines the @JoinTable and/or does not make use of the mappedBy attribute, thus using   a default join table).

这让我认为，由于在该实体中定义了JoinTable批注，因此User将是拥有方。

This lets me think that User would be the owning side as the JoinTable annotation is defined in that entity.

推荐答案

但是我不知道哪个实体（组或用户）是拥有方

But I don't understand which entity (group or user) is the owning side

User 实体是所有者。您在用户中具有组的关系：

The User entity is the owner. You have the relation of groups in User:

/**
 * @ManyToMany(targetEntity="Group", inversedBy="users")
 * @JoinTable(name="users_groups")
 */
private $groups;

上面看， $ groups var包含与该用户关联的所有组，但是如果您注意到属性定义，则 $ groups var的名称相同为 mappedBy 值（mappedBy = 组），方法与您一样：

Look above, $groups var contains the all groups associated to this user, but If you notice the property definition, $groups var has the same name of mappedBy value (mappedBy="groups"), as you did:

/**
 * @ManyToMany(targetEntity="User", mappedBy="groups")
 */
private $users;

mappedBy是什么意思？

此选项指定targetEntity上作为该关系拥有方的属性名称。

This option specifies the property name on the targetEntity that is the owning side of this relation.

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