如何使用Doctrine(DQL)限制左联接的结果 [英] How to limit results of a left-join with Doctrine (DQL)

问题描述

在symfony 2应用程序中，我有2个实体通过 oneToMany关系(用户和集合点)映射. 我正在尝试搜索我的用户实体，并为找到的每个用户加入最后一个集合点. 这个想法是这样的:

In a symfony 2 application, I have 2 entities mapped by a oneToMany relation (user and rendezvous). I'm trying to search into my user entity and join the last rendezvous for each user found. The idea is something like that :

    $qb = $this->createQueryBuilder('p');

    $qb->select('p.id, p.last_name, p.first_name')
       ->leftJoin('p.rendezvous', 'i')
            ->select('i.date')
            ->where('i.user = p.user')
            ->orderBy('i.date', 'DESC')
            ->setFirstResult(0)
            ->setMaxResults(1)                
       ->where('p.user IN ('.$users.')')
       ->orderBy('p.last_name', 'ASC')
       ->addOrderBy('p.first_name', 'ASC');

我应该得到类似这样的结果:

I should have results like :

1，本，图奇，2014-10-15 18:45:00
7，John，Snow，2014-10-16 17:15:00
...

1, Ben, Tooch, 2014-10-15 18:45:00
7, John, Snow, 2014-10-16 17:15:00
...

我尝试使用分页器功能，但没有成功.
非常感谢您的帮助.

I tried to use the paginator function but without any success.
Thank you very much for your help.

推荐答案

当我添加更多列时，我不得不寻找另一种方法.我终于有了一个可以正常工作的DQL查询:

As I add some more columns to get, I had to find another way to do it. I finally got a working DQL query :

$qb->select('p.id, p.last_name, p.first_name, r.date, r.othercolumn')
    ->leftJoin('p.rendezvous', 'r', 'WITH', 'p.id = r.user AND r.date = (SELECT MAX(r2.date) FROM \App\YourBundle\Entity\Rendezvous as r2 WHERE r2.user = p.id)')               
    ->where('p.user IN ('.$users.')')
    ->orderBy('p.last_name', 'ASC')
    ->addOrderBy('p.first_name', 'ASC')
    ->groupBy('p.id');

这篇关于如何使用Doctrine(DQL)限制左联接的结果的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！