调整雄辩的关系-每个父母如何获得N个相关模型？

Question

How to get 2 latest comments of each post? I use laravel 5.2 and Postgres

My comments table

+-----+---------------------+---------+
| id  | created_at          | post_id |
+-----+---------------------+---------+
| 344 | 2014-08-17 21:25:46 |       1 |
| 320 | 2014-08-17 21:25:45 |       1 |
|   4 | 2014-08-17 21:25:26 |       1 |
|  72 | 2014-08-17 21:25:29 |       1 |
| 158 | 2014-08-17 21:25:37 |       2 |
| 423 | 2014-08-17 21:25:50 |       2 |
|  59 | 2014-08-17 21:25:29 |       2 |
| 227 | 2014-08-17 21:25:40 |       2 |
| 308 | 2014-08-17 21:25:45 |       3 |
|  34 | 2014-08-17 21:25:28 |       3 |
+-----+---------------------+---------+

My posts table

+-----+---------------------+---------+
| id  | created_at          | title   |
+-----+---------------------+---------+
| 1   | 2014-08-17 21:25:46 |       a |
| 2   | 2014-08-17 21:25:45 |       b |
| 3   | 2014-08-17 21:25:26 |       c |
+-----+---------------------+---------+

I want to get all posts with latest 2 comments. How can I do this with Eloquent. Thanks in advance!

Answer 1

You need to define additional relation in your Post model that will return 2 latest comments :

class Post extends Model {
  public function latest_comments() {
    return $this->hasMany(Comment::class)->take(2)->orderBy('created_at', 'desc');
  }
}

Now, for every post, you can access its 2 latest comments with $post->latest_comments ;