Laravel many to many 2 level down pivot table - laravel

Question

I am trying to build a Survey Module in Laravel where user can create survey, assign questions and options to the questions in survey.
survey can have multiple questions
survey question can have multiple options
To meet the above requirement I created the following models & tables
Model: Question
Table: questions
| id | question |
| -------- | -------------------------|
| 1 | How is the performance? |
| 2 | How did you know about us|
Model: Option
Table: options
| id | option |
| --- | --------- |
| 1 | Good |
| 2 | Bad |
| 3 | Google |
| 2 | SMS |
Now the relationship between questions and survey will be stored in pivot table
Model: SurveyQuestion
Table: survey_questions
| id | survey_id| question_id |
| ---| -------- |-------------|
| 1 | 1 |1 |
| 1 | 1 |2 |
Upto this point I know how to store data into pivot table using attach/sync.
Now the problem is As per requirement each survey question might have multiple options so I created another pivot table survey_question_option in which I am using survey_questions primary key as foreign key.
Model: SurveyQuestionOption
Table: survey_question_options
| id | survey_question_id| option_id |
| -- | ----------------- |-----------|
| 1 | 1 |1 |
| 1 | 1 |2 |
Now my question is that is it correct to use pivot table primary key as foreign key into another table?
If yes then how can I store data into survey_question_options table using laravel relationships?
If no then what is the better solution?

Answer 1

In this case you can create a Custom Intermediate Table Model (Custom Pivot)
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Relations\Pivot;
class SurveyQuestion extends Pivot
{
public function options()
{
//You need to create a pivot pivot table survey_question_option
//with (survey_question_id, option_id)
return $this->belongsToMany(Option::class, 'survey_question_option');
}
}
Your models will need to recognize this new Pivot Model with the method using(). Here is an example with Survey Model
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class Survey extends Model
{
/**
* The users that belong to the role.
*/
public function questions()
{
return $this
->belongsToMany(Question::class)
->using(SurveyQuestion::class);
}
}
And them you will be able to access via eloquent like this
$survey->questions->pivot->options
For more information you can check the documentation here:
https://laravel.com/docs/8.x/eloquent-relationships#defining-custom-intermediate-table-models