laravel Eloquent 查询列在另一个表中的位置
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Eloquent query where column is in another table
提问by user4913694
I have two tables, postsand likes. I need to create a query, using Eloquent, that gets all posts that have been liked by a specific user_id.
我有两张桌子，posts和likes。我需要使用 Eloquent创建一个查询，获取特定user_id.
In other words, it should be something like this:
换句话说，它应该是这样的：
SELECT * FROM posts p LEFT JOIN likes l ON p.id = l.post_id WHERE l.user_id = 2 ORDER BY l.created_at DESC
poststable:
posts桌子：
+----+---------+------------+-------------+
| id | user_id | message | created_at |
+----+---------+------------+-------------+
| 1 | 2 | Hello! | <SOME TIME> |
| 2 | 3 | World! | <SOME TIME> |
| 3 | 2 | Something. | <SOME TIME> |
| 4 | 2 | Another. | <SOME TIME> |
+----+---------+------------+-------------+
likestable:
likes桌子：
+----+---------+---------+-------------+
| id | post_id | user_id | created_at |
+----+---------+---------+-------------+
| 1 | 1 | 2 | <SOME TIME> |
| 2 | 2 | 2 | <SOME TIME> |
| 3 | 1 | 3 | <SOME TIME> |
| 4 | 3 | 2 | <SOME TIME> |
+----+---------+---------+-------------+
Here is my Postclass:
这是我的Post课：
<?php
class Post extends Eloquent {
protected $table = 'posts';
public function likes()
{
return $this->hasMany('Like');
}
}
And the Likeclass:
和Like班级：
<?php
class Like extends Eloquent {
protected $table = 'likes';
public function post()
{
return $this->belongsTo('Post');
}
}
How can I do this?
我怎样才能做到这一点？
回答by Nicklas Kevin Frank
This should work:
这应该有效：
$userId = //however you get the userid here.
$posts = Post::whereHas('likes', function ($q) use ($userId) {
$q->where('user_id', $user_id);
})->get();
回答by Khan Shahrukh
You can use Laravel's DB class to perform joins on two or more tables, following is how your query will be executed in laravel:
您可以使用 Laravel 的 DB 类在两个或多个表上执行连接，以下是您的查询在 Laravel 中的执行方式：
$users = DB::table('posts')
->leftJoin('likes', 'posts.id', '=', 'likes.post_id')
->select('posts.*', 'likes.*')
->where('likes.user_id', '=', '2')
->orderBy('likes.created_at', 'desc')
->get();
Don't forget to use DB class on the top of your controller;
不要忘记在控制器顶部使用 DB 类；
If you want to do it with eloquent, you should do the follwing:
如果你想用 eloquent 来做，你应该做以下事情：
$result = Post::whereHas('likes', function ($q) use($user_id)
{
$q->where('user_id', $user_id);
})
->orderBy('likes.created_at')
->get();
