Laravel: How should I update this relationship? - php

Question

Suppose I have the following tables:
User:
-userID
-userName
...
Exercises:
-exerciseID
...
User model:
<?php
use Illuminate\Auth\UserInterface;
use Illuminate\Auth\Reminders\RemindableInterface;
class User extends Eloquent implements UserInterface, RemindableInterface {
/**
* The database table used by the model.
*
* #var string
*/
protected $table = 'users';
protected $primaryKey = 'userID';
...
public function hasPassedExercises() {
return $this->hasMany('Exercise', 'exerciseID');
}
}
I want to say that a User has many completedExercises, so when the user completes an exercise, I update the model like so:
Route::post('dbm/userPassedExercise', function () {
$user = User::with('hasPassedExercises')->find($_POST['userID']);
$exercise = Exercise::find($_POST['exerciseID']);
$user->hasPassedExercises->save($exercise);
});
However, this has no effect on any underlying table, as far as I have understood. I'm trying to make sense of the documentation and see how it applies to my problem. So my question is what is the right course of action to do here.
Should I create a table users_completed_exercises that has userID and exerciseID as foreign keys, and if so, how do I link them to my user when I do the update? Or is there a more elegant solution?

Answer 1

Indeed, you have to use a relationship table (called pivot table).
In the laravel documentation, you have to name your pivot table with your tables name ordered by their name (you have not to, but it's prefered).
We'll take your naming convention so : users_completed_exercises
So here we shoud have this :
users:
- userId // Unsigned Int PRIMARY KEY AUTO_INCREMENT
Exercises:
- exerciseId // Unsigned Int PRIMARY KEY AUTO_INCREMENT
users_completed_exercises:
- id // Unsigned Int PRIMARY KEY AUTO_INCREMENT
- exerciseId // Unsigned Int FOREIGN KEY REFERECES EXERCICES ON ID
- userId // Unsigned Int FOREIGN KEY REFERECES USERS ON ID
On the user model, you should have :
public function passedExercises()
{
// Alphabetical order of your id's are here, very important because laravel
// retreives the good ID with your table name.
return $this->belongsToMany('Exercise', 'users_completed_exercises', 'exerciseId', 'userId');
}
And the inverse on Excercise Model
public function usersWhoPassed()
{
// Alphabetical order of your id's are here, very important because laravel
// retreives the good ID with your table name.
return $this->belongsToMany('User', 'users_completed_exercises', 'exerciseId', 'userId');
}
Retreiving infos are now, so easy.
Route::post('dbm/userPassedExercise', function () {
// Don't use $_POST with laravel, they are exceptions indeed, but avoid as much as
// possible.
$user = User::find(Input::get('userId'));
$exercise = Exercise::find(Input::get('exerciseId'));
// Very important, use () on relationships only if you want to continue the query
// Without () you will get an Exercises Collection. Use ->get() or ->first() to end
// the query and get the result(s)
$exercise->usersWhoPassed()->save($user);
});
You can easly check if user has passed an exercise too
Route::get('/exercises/{id}/passed_users', function($id)
{
$exercise = Exercise::find($id);
if ($exercise->usersWhoPassed()
->where('userId', '=', Input::get('userId'))->count()) {
return 'User has passed';
}
return 'User has failed';
});