我可以使用“开”关键字在DQL中还是需要使用Native Query？ [英] Can I use "ON" keyword in DQL or do I need to use Native Query?

问题描述

我在Post和PostVote之间有一对一的关系。我想要检索一篇文章，以及一个具体的用户投票的方式。在DQL中，我想检索Post和相关的PostVote实体，但只有一个user_id是例如5.

我似乎无法使用ON sql关键字如下：

   - > createQuery（'SELECT p，pv FROM Post p LEFT JOIN p.postvotes ON pv.user =：userid WHERE p.id =：postid'）
  

如果我使用WHERE过滤掉结果，它会创建一个问题，除非至少有一个postvote对象存在，否则不会显示结果：

   - > createQuery（'SELECT p，pv FROM Post p LEFT JOIN p.postvotes WHERE p.id =：postid'AND pv.user =：userid）
  

是本机查询我唯一可以实现的方式吗？

解决方案

您必须使用WITH关键字DQL完成此操作：

  SELECT p，pv FROM Post p LEFT JOIN p.postvotes WITH pv.user =：userid WHERE p .id =：postid 
  

I have a oneToMany relationship between Post and PostVote. I would like to be able to retrieve a Post and how a specific user voted on it. In DQL I would like to retrieve Post and related PostVote entity, but only one where user_id is for example 5.

I don't seem to be able to use ON sql keyword like this:

->createQuery('SELECT p, pv FROM Post p LEFT JOIN p.postvotes ON pv.user = :userid WHERE p.id = :postid')

And if I use WHERE to filter out results, it create a problem and does not display a result unless at least one postvote object exists:

->createQuery('SELECT p, pv FROM Post p LEFT JOIN p.postvotes WHERE p.id = :postid' AND pv.user = :userid)

Is Native Query the only way I can achieve this?

解决方案

You have to use the WITH keyword in DQL to accomplish this:

SELECT p, pv FROM Post p LEFT JOIN p.postvotes WITH pv.user = :userid WHERE p.id = :postid

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