mysql - 学说 2 多对多翻译

Question

我对原则 2 有疑问。 我有以下数据库表: 因此，Doctrine 生成从站点的桌面设置中检索数据的实体，但我需要从 desk_settings 表中检索所有设置并使用 desk_id 从 desk_settings_values 表中覆盖其值

数据库图像 -> https://docs.google.com/file/d/0B7rOFTJGfJwTWEQ3bXZFU1hXZlU/edit?usp=sharing

用脚本生成的 Doctrine 实体:

/**
 * Desk
 *
 * @ORM\Table(name="desk")
 * @ORM\Entity
 */
class Desk
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer", nullable=false)
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id;

    /**
     * @var string
     *
     * @ORM\Column(name="code", type="string", length=100, nullable=false)
     */
    private $code;

    /**
     * @var string
     *
     * @ORM\Column(name="description", type="string", length=255, nullable=false)
     */
    private $description;

    /**
     * @var \DateTime
     *
     * @ORM\Column(name="created", type="datetime", nullable=false)
     */
    private $created;

    /**
     * @var \Doctrine\Common\Collections\Collection
     *
     * @ORM\ManyToMany(targetEntity="PayBox\Entity\DeskSettings", mappedBy="desk")
     */
    private $deskSettings;
}

use Doctrine\ORM\Mapping as ORM;

/**
 * DeskSettings
 *
 * @ORM\Table(name="desk_settings")
 * @ORM\Entity
 */
class DeskSettings
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer", nullable=false)
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id;

    /**
     * @var string
     *
     * @ORM\Column(name="setting_key", type="string", length=100, nullable=false)
     */
    private $settingKey;

    /**
     * @var string
     *
     * @ORM\Column(name="setting_value", type="string", length=255, nullable=false)
     */
    private $settingValue;

    /**
     * @var \DateTime
     *
     * @ORM\Column(name="created", type="datetime", nullable=false)
     */
    private $created;

    /**
     * @var \Doctrine\Common\Collections\Collection
     *
     * @ORM\ManyToMany(targetEntity="PayBox\Entity\Desk", inversedBy="deskSettings")
     * @ORM\JoinTable(name="desk_settings_values",
     *   joinColumns={
     *     @ORM\JoinColumn(name="desk_settings_id", referencedColumnName="id")
     *   },
     *   inverseJoinColumns={
     *     @ORM\JoinColumn(name="desk_id", referencedColumnName="id")
     *   }
     * )
     */
    private $desk;
 }

Answer 1

来自 Doctrine 文档:

Why are many-to-many associations less common? Because frequently you want to associate additional attributes with an association, in which case you introduce an association class. Consequently, the direct many-to-many association disappears and is replaced by one-to-many/many-to-one associations between the 3 participating classes.

您需要将类结构更改为一对多/多对一。 See this blog .