Laravel Eloquent Multiple Relationship - laravel

Question

I want this object only if it has all the necessary relationships.
At the moment my code:
StudentController
$student = Student::with('inscriptions','inscriptions.classroom')
->find($request->user()->id);
Student
public function inscriptions()
{
return $this->hasMany('App\InscribedStudent');
}
InscribedStudent - Note: "Registration Open"
public function classroom()
{
return $this->hasOne('App\Classroom', 'id')->where('registration_open', true);
}
Json Return When haven't registration opened
{
"inscriptions": [
{
"id": 1,
"student_id": 1,
"classroom_id": 1,
"deleted_at": null,
"created_at": "2019-07-04 23:34:48",
"updated_at": "2019-07-04 23:34:48",
"classroom": null
}
]
}
I want to do something like that, because I don't need the object InscribedStudent if I haven't a classroom.
public function inscriptions()
{
return $this->hasMany('App\InscribedStudent')
->hasOne('App\Classroom', 'id')
->where('registration_open', true);
}

Answer 1

You can use has() or whereHas() to check that the classroom exists.
https://laravel.com/docs/5.8/eloquent-relationships#querying-relationship-existence
// this will only get students that have a classroom through inscriptions
$students = Student::has('incriptions.classroom')
->with('inscriptions.classroom')
->get();
// this will get students, but only fetch inscriptions if there is a classroom
$students = Student::with(['inscriptions' => function($inscriptionQuery) {
$inscriptionQuery->has('classroom')->with('classroom');
}])
->get();
You can also make a custom scope on the Student model if you want to use that instead.
// this will only get students that have a classroom through inscriptions
public function scopeHasClassroom($query)
{
$query->has('inscriptions.classroom')
->with('inscriptions.classroom');
}
// this will get students, but only fetch inscriptions if there is a classroom
public function scopeHasClassroom($query)
{
$query->with(['inscriptions' => function($inscriptionQuery) {
$inscriptionQuery->has('classroom')->with('classroom');
}]);
}
Then you can call the custom scope like this:
$students = Student::hasClassroom()->get();
https://laravel.com/docs/5.8/eloquent#query-scopes