主观2自我查询 [英] Doctrine 2 Self Join Query
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问题描述
我现在还不太了解Doctrine,而我正在尝试检索用户要遵循的建议列表。
I'm still pretty new to Doctrine and I'm trying to retrieve a suggest list of users to follow.
所以基本上,给定一个用户A需要选择用户A遵循的用户遵循的所有用户,不包括用户A已经遵循的用户。
So basically, given an user A, I need to select all users that are followed by the users that user A follow, excluding users that user A already follow.
如何使用Doctrine查询构建器? / p>
How could I do that with Doctrine query builder ?
class User
{
...
/**
* @ORM\ManyToMany(targetEntity="User", inversedBy="followees")
* @ORM\JoinTable(name="user_followers",
* joinColumns={@ORM\JoinColumn(name="user_id", referencedColumnName="id", onDelete="CASCADE")},
* inverseJoinColumns={@ORM\JoinColumn(name="follower_id", referencedColumnName="id", onDelete="CASCADE")}
* )
*/
private $followers;
/**
* @ORM\ManyToMany(targetEntity="User", mappedBy="followers")
*/
private $followees;
}
编辑:根据slaur4解决方案,我试过这个
EDIT: According to slaur4 solution, I tried this
$qb = $this->createQueryBuilder('u');
$qb->select('suggestions')
->join('u.followees', 'followees')
->join('followees.followers', 'suggestions')
->where('u.id = :id')
->andWhere($qb->expr()->notIn('suggestions.id', 'u.followees'))
->setParameter('id', $user->getId());
但它给了我以下例外:
QueryException: [Syntax Error] line 0, col 171: Error: Expected Literal, got 'u'
推荐答案
这是一个自引用的查询。我会尝试这样:
It's a self-referencing query. I would try this :
QueryBuilder(用户Symfony2存储库)
<?php
//Subquery to exclude user A followees from suggestions
$notsQb = $this->createQueryBuilder('user')
->select('followees_excluded.id')
->join('user.followees', 'followees_excluded')
->where('user.id = :id');
$qb = $this->createQueryBuilder('suggestions');
$qb->join('suggestions.followers', 'suggestions_followers')
->join('suggestions_followers.followers', 'users')
->where('users.id = :id')
->andWhere('suggestions.id != :id') //Exclude user A from suggestions
->andWhere($qb->expr()->notIn('suggestions.id', $notsQb->getDql()))
->setParameter('id', $userA->getId());
$query = $qb->getQuery();
$users = $query->getResult(); // array of User
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