Laravel ORM many to many relationship acts like one to many - php

Question

My problem is I am trying to establish a many to many relationship between posts and genre. Here is what I have done so far.
class Post extends Model
{
public function genres()
{
return $this->belongsToMany('App\Genre');
}
}
class Genre extends Model
{
public function posts()
{
return $this->hasMany('App\Post');
}
}
genre Table
+----+--------+
| id | name |
+----+--------+
| 1 | News |
| 2 | Sports |
+----+--------+
post table
+----+----------------+
| id | title |
+----+----------------+
| 1 | Political News |
| 2 | Sport Update |
+----+----------------+
genre_post table
+----+---------+----------+
| id | post_id | genre_id |
+----+---------+----------+
| 1 | 1 | 1 |
| 2 | 1 | 2 |
| 3 | 2 | 2 |
+----+---------+----------+
When I am trying to acess genre list of a post, everything works fine.
Post::where('slug', '=', $id)->with("genres")->first(); // no problem
But when I tried the opposite it's not working.
$posts = Genre::where( "slug", "=", $id )->with("posts")->first();
I am getting the following error.
Column not found: 1054 Unknown column 'post.genre_id' in 'where
clause' (SQL: select * from post where post.genre_id
I understand the laravel is trying to aceess genre_id column from post table which doesn't exists since it's a many to many relation which means one post can contain more than one genre and one genre can contain more than one post.
Any idea how can I resolve this?

Answer 1

This is expected since hasMany itself an one to many relationship. Use belongsToMany instead.
class Genre extends Model
{
public function posts()
{
return $this->belongsToMany('App\Post');
}
}