Symfony 具有不同目标实体的许多关联
因此,我有一个媒体实体,它可以从不同的目标实体“事件”、“类别”、“页面”中引用 现在我的媒体实体中有多个@manytomy关联,如下所示:Symfony 具有不同目标实体的许多关联,symfony,doctrine-orm,Symfony,Doctrine Orm,因此,我有一个媒体实体,它可以从不同的目标实体“事件”、“类别”、“页面”中引用 现在我的媒体实体中有多个@manytomy关联,如下所示: /** * @ORM\ManyToMany(targetEntity="Event", mappedBy="medias") */ private $events; /** * @ORM\ManyToMany(targetEntity="Feature", mappedBy="medias") */ private $features; /**
/**
* @ORM\ManyToMany(targetEntity="Event", mappedBy="medias")
*/
private $events;
/**
* @ORM\ManyToMany(targetEntity="Feature", mappedBy="medias")
*/
private $features;
/**
* @ORM\ManyToMany(targetEntity="Category", mappedBy="medias")
*/
private $categories;
/**
* @ORM\ManyToMany(targetEntity="Media", inversedBy="events")
* @ORM\JoinTable(name="events_medias")
*/
private $medias;
Table "public.events_medias"
Column | Type | Modifiers
----------+---------+-----------
media_id | integer | not null
event_id | integer | not null
Table "public.medias_entities"
Column | Type | Modifiers
--------------+---------+-----------
media_id | integer | not null
entity_id | integer | not null
entity_class | string | not null
在目标实体中,我得到了如下结果:
/**
* @ORM\ManyToMany(targetEntity="Event", mappedBy="medias")
*/
private $events;
/**
* @ORM\ManyToMany(targetEntity="Feature", mappedBy="medias")
*/
private $features;
/**
* @ORM\ManyToMany(targetEntity="Category", mappedBy="medias")
*/
private $categories;
/**
* @ORM\ManyToMany(targetEntity="Media", inversedBy="events")
* @ORM\JoinTable(name="events_medias")
*/
private $medias;
Table "public.events_medias"
Column | Type | Modifiers
----------+---------+-----------
media_id | integer | not null
event_id | integer | not null
Table "public.medias_entities"
Column | Type | Modifiers
--------------+---------+-----------
media_id | integer | not null
entity_id | integer | not null
entity_class | string | not null
这导致我的数据库中有许多连接表如下所示:
/**
* @ORM\ManyToMany(targetEntity="Event", mappedBy="medias")
*/
private $events;
/**
* @ORM\ManyToMany(targetEntity="Feature", mappedBy="medias")
*/
private $features;
/**
* @ORM\ManyToMany(targetEntity="Category", mappedBy="medias")
*/
private $categories;
/**
* @ORM\ManyToMany(targetEntity="Media", inversedBy="events")
* @ORM\JoinTable(name="events_medias")
*/
private $medias;
Table "public.events_medias"
Column | Type | Modifiers
----------+---------+-----------
media_id | integer | not null
event_id | integer | not null
Table "public.medias_entities"
Column | Type | Modifiers
--------------+---------+-----------
media_id | integer | not null
entity_id | integer | not null
entity_class | string | not null
我真的不喜欢这样,它使得数据库非常庞大和复杂。
我想在一个表中进行所有这些关联,其中目标实体的类被持久化。大概是这样的:
/**
* @ORM\ManyToMany(targetEntity="Event", mappedBy="medias")
*/
private $events;
/**
* @ORM\ManyToMany(targetEntity="Feature", mappedBy="medias")
*/
private $features;
/**
* @ORM\ManyToMany(targetEntity="Category", mappedBy="medias")
*/
private $categories;
/**
* @ORM\ManyToMany(targetEntity="Media", inversedBy="events")
* @ORM\JoinTable(name="events_medias")
*/
private $medias;
Table "public.events_medias"
Column | Type | Modifiers
----------+---------+-----------
media_id | integer | not null
event_id | integer | not null
Table "public.medias_entities"
Column | Type | Modifiers
--------------+---------+-----------
media_id | integer | not null
entity_id | integer | not null
entity_class | string | not null
这在条令中是否可行?如果可能,性能如何?您应该使用
您应该创建超类MediaType
,作为Media
和终端实体之间的中介:
/**
* @Entity
* @InheritanceType("JOINED")
* @DiscriminatorColumn(name="entity_class", type="string")
* @DiscriminatorMap({"event" = "Event", "feature" = "Feature", "category" = "Category"})
*/
class MediaType
{
/**
* @ORM\ManyToMany(targetEntity="Media", inversedBy="mediaType")
*/
protected $medias;
}
/** @Entity */
class Event extends MediaType
{
// ...
}
/** @Entity */
class Category extends MediaType
{
// ...
}
/** @Entity */
class Feature extends MediaType
{
// ...
}