Laravel Create multiple records in Pivot table - laravel

Question

I'm trying to create a function in our Laravel 5.8 app that would add multiple records to a pivot table. At present we have the following setup;
Users
Training Courses
Users Training Courses (pivot table for the above relationships, with a few extra fields)
I want to be able to show all users in the database, then check their name, pick a training course and hit "Add" and it'll create a record in the pivot table for each user that was selected.
I can't figure out where to start with this - it seems like I need to have a "for each user selected, run the store function" loop in the controller, but I have no idea where to start.
I wasn't sure if there was an easy way to do this in eloquent or not. Is there a simple way to do this?

Answer 1

Eloquent does this automatically if you set up the relationships correctly and you don't have to worry about pivot tables.
class Users
{
public function trainingCourses()
{
return $this->hasMany(TrainingCourses::class);
}
}
class TrainingCourses
{
public function user()
{
return $this->belongsTo(User::class);
}
}
Then you can use the save() method to create the relationship. But I find it better to wrap this function inside a helper method that you can use throughout your code:
class Users
{
...
public function assignTrainingCourse(TrainingCourse $trainingCourse)
{
return $this->trainingCourses()->save($trainingCourse);
}
}
In your code, you could then do something as simple as this:
$user = User::find(1);
$trainingCourse = TrainingCourse::find(1);
$user->assignTrainingCourse($trainingCourse);
Building on this, suppose you have the following route to assign a training course, where it expects a trainingcourse_id in the request:
Route::post('/users/{user}/trainingcourses', 'UserTrainingCoursesController#store');
Thanks to route model binding, Laravel can inference the parent model (user) from the URL, and your controller might look like this:
// UserTrainingCoursesController.php
public function store(User $user)
{
$trainingCourse = TrainingCourse::find(request()->input('trainingcourse_id'));
$user->assignTrainingCourse($trainingCourse);
return back();
}
Of course, you'll want to put some validation in here, but this should get you started.