laravel-三对多关系

Question

I have 3 tabels: users, teachers And posts.

users :
id - integer
name - string

teachers :
id - integer
teacher_id - integer
user_id - integer
name - string

posts :
id - integer
user_id - integer
title - string

User Model:

class User extends Model
{
  public function teachers()
  {
    return $this->hasMany('App\Teacher');
  }
}

Teacher Model:

class Teacher extends Model
{
  public function posts()
  {
    return $this->hasMany('App\Post', 'user_id','teacher_id');
  }
}

? Question is How can I use sth like this:

$user = User::find(1);
$teacher_posts = $user->teachers()->posts

Answer 1

I'm sort of new to laravel but here is my take.

What I have realized is that typically your many to many relationships will require a pivot table.

users :(id, name)

teachers :(id, teacher_id, name)

teacher_users :(id, user_id, teacher_id)

posts :(id, user_id, title)

And your Eloquent models will look like this.

class User extends Model
{
  public function teachers()
  {
    return $this->belongsToMany('App\Teacher');
  }

  public function posts()
  {
    return $this->hasMany('App\Post');
  }
}


class Teacher extends Model
{
  public function users()
  {
    return $this->belongsToMany('App\User');
  }
}

$user = User::find(1);
$user_posts = $user->posts();

Check out the documentation here for more details