Laravel -检索直接/间接枢轴表订阅服务器

Question

我很难用laravel计算出这一点；对于订阅者关系，我们有两个枢轴表：

订阅者可以订阅以下问题：

question_subscriber
id   question_id  subscriber_id
1        2            3
2        2            4
3        3            1
4        3            2

订阅者可以订阅用户：

user_subscriber
id  user_id  subscriber_id
1      1         6
2      1         7
3      2         1

有问题所有者的普通问题表：

questions
id  question  user_id
1     abc?       1
2     xyz?       1
3     123?       2

在它们的模型中正确地设置了枢轴关系，并且我可以使用foreach、问题订阅者、$question->subscribersQuestion as $subscriber或用户$user->subscribersUser as $subscriber来提取。

但是，我们如何提取属于用户的所有订阅者(直接或间接地(通过他们拥有的问题))？

例如，这些应该都是为user 1检索的订阅服务器。

6 // subscribed to directly
7 // subscribed to directly
3 // subscribed to through question
4 // subscribed to through question

你知道在Laravel最有效的方法吗？

Answer 1

这将是最简单的方法：

// assuming this setup: 
User hasMany Question
User belongsToMany User (subscribers - direct)
Question belongsToMany User (subscribers - indirect)

// we don't need this, since we pass it by reference to the closure,
// but for clarity let's initialize this variable:
$indirectSubscribers = null;

$user = User::with(['questions.subscribers' => function ($q) use (&$indirectSubscribers) {
  // get all indirect subscribers (cost of additional query)
  $indirectSubscribers = $q->get()->unique();
}])->find($userId);

// merge with directs subscribers
$allSubscribers = $user->subscribers->merge($indirectSubscribers);