Need to make a relationship between the three models - laravel

Question

We have a user who can learn in several ways. In each direction, the user has some level. There are three models: user, direction, level. They need to be linked in such a way that the user can get a list of its directions, and in each direction its level. For example, $user->directions[0]->level.
Once again regarding the relationship. A user may have many directions, and a direction many users (many to many). Direction can have many levels, but the level is only one direction (one to many).
I use Laravel 5.8.

Answer 1

Since a User has many Directions and a Direction has many Users you should use belongsToMany (Eloquent relationship which related to many-to-many relationship of database.) relationship.
And a Direction has many Levels but a Level has only one Direction you should use hasMany and belongsTo on Direction and Level respectively.
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
public function directions()
{
return $this->belongsToMany(Direction::class);
}
}
use Illuminate\Database\Eloquent\Model;
class Direction extends Model
{
public function levels()
{
return $this->hasMany(Level::class);
}
public funciton users()
{
return $this->belongsToMany(User::class);
}
}
use Illuminate\Database\Eloquent\Model;
class Level extends Model
{
public function direction()
{
return $this->belongsTo(Direction::class);
}
}
UPDATE
In case you haven't defined database tables. This is how you may do it.
You can use Laravel migrations to create database tables.
User Table
Schema::create('users', function (Blueprint $table) {
$table->increment('id')->primary();
// all the other columns goes here.
});
Directions Table
Schema::create('directions', function (Blueprint $table) {
$table->increment('id')->primary();
// all the other columns goes here.
});
Directions Users Table
Schema::create('direction_user_table', function (Blueprint $table) {
$table->unSignedInteger('user_id');
$table->unSignedInteger('direction_id');
// all the other columns goes here.
});
Levels Table
Schema::create('levels', function (Blueprint $table) {
$table->increment('id')->primary();
$table->unSignedInteger('direction_id');
// all the other columns goes here.
});

Answer 2

You can use relationships like below in laravel model.
For User model
public function directions()
{
return $this->hasMany('App\Direction','user_id');
}
For Direction model
public function users()
{
return $this->hasMany('App\User','id','user_id');
}
public function levels()
{
return $this->hasMany('App\Level','direction_id');
}
For Level model
public function direction()
{
return $this->hasOne('App\Direction','id','direction_id');
}