与DQL的学说2限制关联 [英] Doctrine 2 Restricting Associations with DQL

问题描述

Doctrine 2.1中似乎有一个不为人知的地方，要返回一个关联的子集
并不容易。

http：// www。 doctrine-project.org/docs/orm/2.1/en/reference/limitations-and-known-issues.html#restricing-associations

文档建议编写一个存储库查找方法，这很有意义，因为那是我要做的第一件事。

但是在实体中不引用EntityManager时，我可以

有没有建议的解决此问题的策略？ / p>

这是我对他们建议的解决方案的解释。

  class Category 
 {
受保护的$ id; 
受保护的物品； // PesistentCollection 
受保护的$ em; // EntityManager是从哪里来的？ 
 
公共函数getVisableArticles（）
 {
 return $ this-> em-> getRepository（'Article'）
-> getVisibleByCategory（$ this） ; 
} 
} 
  

解决方案

1. 在任何情况下，在实体中拥有EntityManager都不是一件好事。
   （改为注入您的存储库）


2. 类别不是文章的唯一根源因为它无法确定所需的文章，所以您需要一个文章存储库。

我会做什么：

 类别类别
 {
受保护的$ id; 
受保护的物品； // PesistentCollection 
 
公共函数getVisableArticles（IArticleRepository $ articleRepository）
 {
 return $ articleRepository-> getVisibleByCategory（$ this）; 
} 
} 
 
接口IArticleRepository 
 {
函数getVisibleByCategory（Category $ category）; 
} 
  

您的学说的存储库将实现IArticleRepository，并且该类对您一无所知数据存储/原则。

There seems to be an over sight in Doctrine 2.1 where it isn't easy to return a subset collection for an association.

http://www.doctrine-project.org/docs/orm/2.1/en/reference/limitations-and-known-issues.html#restricing-associations

The docs recommend to write a repository find method, which makes sense because that was the first thing I though of doing.

However without having a reference to the EntityManager within an Entity I can't see how you would retrieve the association's Repository and this seems to defeat the point of separating the Domain from the Database?

Is there a recommended strategy for this problem?

Here is my interpretation of their suggested solution.

class Category
{
    protected $id;
    protected $articles; // PesistentCollection
    protected $em; // The EntityManager from somewhere?

    public function getVisableArticles()
    {
        return $this->em->getRepository('Article')
                    ->getVisibleByCategory($this);
    }
}

解决方案

1. Having entitymanager in an entity isn't a good thing in any case (inject your repository instead)
2. Category isn't the only root for articles because it can't daterimne what articles you need, so you need a repository for articles.

What i would do:

class Category
{
    protected $id;
    protected $articles; // PesistentCollection

    public function getVisableArticles(IArticleRepository $articleRepository)
    {
        return $articleRepository->getVisibleByCategory($this);
    }
}

interface IArticleRepository
{
    function getVisibleByCategory(Category $category);
}

Your doctrine's repository would implement IArticleRepository and the class won't know anything about your data storage/doctrine.

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