如何在不知道其名称的情况下获取Doctrine2实体标识符 [英] How to get Doctrine2 entity identifier without knowing its name
问题描述
我正在尝试使用Doctrine2在我的Symfony2的基础Entity类上为数据库创建抽象的getId方法,该数据库的主键在表之间的名称不一致。
I am attempting to create an abstracted getId method on my base Entity class in Symfony2 using Doctrine2 for a database where primary keys are named inconsistently across tables.
检查时我看到的实体对象有一个私有的'_identifier'属性,其中包含我要检索的信息,但不确定如何正确访问它。
When inspecting entity objects I see there is a private '_identifier' property that contains the information I am trying to retrieve but I am not sure how to properly access it.
我假设有一些简单的教义魔术类似于:
I'm assuming there is some simple Doctrine magic similar to:
public function getId()
{
return $this->getIdentifier();
}
但是我没有设法在任何地方的Intertube上找到它。
But I haven't managed to find it on the intertubes anywhere.
推荐答案
您可以通过 EntityManager#getClassMetadata()
访问此信息。一个示例如下所示:
You can access this information via EntityManager#getClassMetadata()
. An example would look like this:
// $em instanceof EntityManager
$meta = $em->getClassMetadata(get_class($entity));
$identifier = $meta->getSingleIdentifierFieldName();
如果您的实体具有复合主键,则需要使用而是使用$ meta-> getIdentifierFieldNames()
。当然,使用此方法,您将需要访问 EntityManager
的实例,因此此代码通常放置在自定义存储库,而不是实体本身。
If your entity has a composite primary key, you'll need to use $meta->getIdentifierFieldNames()
instead. Of course, using this method, you'll need access to an instance of EntityManager
, so this code is usually placed in a custom repository rather than in the entity itself.
希望有帮助。
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