Question

我很难在laravel中搞清楚这一点;对于订户关系，我们有2个数据透视表：

订阅者可以订阅问题：

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

问题所有者的正常问题表：

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

我们可以在他们的模型中正确设置数据透视关系，我可以使用foreach，问题的订阅者$question->subscribersQuestion as $subscriber或用户的订阅者$user->subscribersUser as $subscriber：

但是，我们怎样才能拉出属于用户的所有订阅者（直接或间接（通过他们拥有的问题））？

例如，这些应该是user 1的所有检索订阅者：

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

有关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);

Laravel - 检索直接/间接数据透视表订阅者

1 个答案: