問題描述

在 Eloquent 的文檔中，據說我可以將所需關系的鍵傳遞給 hasManyThrough.

In the documentation of Eloquent it is said that I can pass the keys of a desired relationship to hasManyThrough.

假設我有名為 Country、User、Post 的模型.通過用戶模型，國家模型可能有許多帖子.也就是說，我可以直接調用:

Lets say I have Models named Country, User, Post. A Country model might have many Posts through a Users model. That said I simply could call:

$this->hasManyThrough('Post', 'User', 'country_id', 'user_id');

到目前為止一切正常！但是我如何才能只為 id 為 3 的用戶獲取這些帖子?

有人可以幫忙嗎?

推薦答案

就這樣:

models: Country 有很多 User 有很多 Post

models: Country has many User has many Post

這允許我們在您的問題中使用 hasManyThrough :

This allows us to use hasManyThrough like in your question:

// Country model
public function posts()
{
  return $this->hasManyThrough('Post', 'User', 'country_id', 'user_id');
}

您想獲取此關系的給定用戶的帖子，因此:

You want to get posts of a given user for this relation, so:

$country = Country::first();
$country->load(['posts' => function ($q) {
  $q->where('user_id', '=', 3);
}]);
// or
$country->load(['posts' => function ($q) {
  $q->has('user', function ($q) {
    $q->where('users.id', '=', 3);
  });
})

$country->posts; // collection of posts related to user with id 3

<小時>

但是如果你改用它，它會更容易、更易讀和更有說服力:(因為當您在尋找 id 為 3 的用戶的帖子時，它與國家無關)

BUT it will be easier, more readable and more eloquent if you use this instead: (since it has nothing to do with country when you are looking for the posts of user with id 3)

// User model
public function posts()
{
  return $this->hasMany('Post');
}

// then
$user = User::find(3);
// lazy load
$user->load('posts');
// or use dynamic property
$user->posts; // it will load the posts automatically
// or eager load
$user = User::with('posts')->find(3);

$user->posts; // collection of posts for given user

總結一下:hasManyThrough是一種直接獲取嵌套關系的方法，即.給定國家/地區的所有帖子，而不是搜索特定的 through 模型.

To sum up: hasManyThrough is a way to get nested relation directly, ie. all the posts for given country, but rather not to search for specific through model.

這篇關于Laravel/Eloquent : hasManyThrough WHERE的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！