Symfony和Doctrine中的HowToMany和OneToMany如何？

Question

在解释实体之间关系的创建时,我发现文档很差.所以,我将不得不向我的StackExchangers同事寻求帮助.所以,我正在尝试构建以下案例:

情况1

A User属于一个或多个Group,a Group可以有多个Permission.A User也可以有Permission.

案例2

A Ticket有a Category,multiple Tag和multiple Comment.

提前致谢!

Answer 1

当然可以.首先要明白的是,没有"一种方法"可以做到这一点.Doctrine在定义关系方面提供了很大的灵活性- 即使多个定义产生完全相同的DDL(这一点很重要,理解 - 一些映射选择只会影响ORM的对象端,而不是模型-侧)

这是您的用户/组/权限示例,实际上是所有多对多关联(我排除了所有不相关但必需的代码,如PK列定义)

<?php

namespace Your\Bundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Doctrine\Common\Collections\ArrayCollection;

/**
 * @ORM\Entity
 */
class User
{
  /**
   * Many-To-Many, Unidirectional
   *
   * @var ArrayCollection $groups
   *
   * @ORM\ManyToMany(targetEntity="Group")
   * @ORM\JoinTable(name="user_has_group",
   *      joinColumns={@ORM\JoinColumn(name="user_id", referencedColumnName="id")},
   *      inverseJoinColumns={@ORM\JoinColumn(name="group_id", referencedColumnName="id")}
   * )
   */
  protected $groups;

  /**
   * Many-To-Many, Unidirectional
   *
   * @var ArrayCollection $permissions
   *
   * @ORM\ManyToMany(targetEntity="Permission")
   * @ORM\JoinTable(name="user_has_permission",
   *      joinColumns={@ORM\JoinColumn(name="user_id", referencedColumnName="id")},
   *      inverseJoinColumns={@ORM\JoinColumn(name="permission_id", referencedColumnName="id")}
   * )
   */
  protected $permissions;

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

/**
 * @ORM\Entity
 */
class Group
{
  /**
   * Many-To-Many, Unidirectional
   *
   * @var ArrayCollection $permissions
   *
   * @ORM\ManyToMany(targetEntity="Permission")
   * @ORM\JoinTable(name="group_has_permission",
   *      joinColumns={@ORM\JoinColumn(name="group_id", referencedColumnName="id")},
   *      inverseJoinColumns={@ORM\JoinColumn(name="permission_id", referencedColumnName="id")}
   * )
   */
  protected $permissions;

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

/**
 * @ORM\Entity
 */
class Permission {}

如果您对此处发生的事情有疑问,请与我们联系.

现在,到你的第二个例子

<?php

namespace Your\Bundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Doctrine\Common\Collections\ArrayCollection;

/**
 * @ORM\Entity
 */
class Ticket
{
  /**
   * Many-To-One, Unidirectional
   *
   * @var Category
   *
   * @ORM\ManyToOne(targetEntity="Category")
   * @ORM\JoinColumn(name="category_id", referencedColumnName="id")
   */
  protected $category;

  /**
   * Many-To-Many, Unidirectional
   *
   * @var ArrayCollection $permissions
   *
   * @ORM\ManyToMany(targetEntity="Tag")
   * @ORM\JoinTable(name="tickt_has_tag",
   *      joinColumns={@ORM\JoinColumn(name="ticket_id", referencedColumnName="id")},
   *      inverseJoinColumns={@ORM\JoinColumn(name="tag_id", referencedColumnName="id")}
   * )
   */
  protected $tags;

  /**
   * One-To-Many, Bidirectional
   *
   * @var ArrayCollection $comments
   *
   * @ORM\OneToMany(targetEntity="Comment", mappedBy="ticket")
   */
  protected $comments;

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

/**
 * @ORM\Entity
 */
class Comment
{
  /**
   * Many-To-One, Bidirectional
   *
   * @var Ticket $ticket
   *
   * @ORM\ManyToOne(targetEntity="Ticket")
   * @ORM\JoinColumn(name="ticket_id", referencedColumnName="id")
   */
  protected $ticket=null;
}

/**
 * @ORM\Entity
 */
class Tag {}

/**
 * @ORM\Entity
 */
class Category {}

和以前一样,如果你想要解释的话,请告诉我.

PS这些都没有经过实际测试,我只是快速地在我的IDE中将它击败了.可能有一两个错字;)