Accessing The Laravel SQL Relationship without Local Key - php

Question

I am new in Laravel. I have two models: User and Car. I wish to access the car data from the user entity in the controller, but I could not find how to do it. In addition, the database is fixed with the columns and the administrator refuses to do any change on it.
Here is the User model:
class User extends Model {
protected $primaryKey = 'idUser';
protected $fillable = [
'name', 'age', 'address', 'gender', 'phone', 'email'
];
}
And then this is my Car model:
class Car extends Model {
protected $primaryKey = 'idCar';
protected $fillable = [
'carNumber', 'carMachineNumber', 'type', 'model', 'year', 'idUser'
];
public user(){
return $this->belongsTo(User::class, 'idUser');
}
}
In the controller and the blade templates, I wish I can access the car data from the user entity. For example when I want to get the car type data then I would access it by:
$user->car->type
It would be even better if I will be able to access all of the cars a user has by this line of code:
$user->car->all();
How to make it possible? What should I add to the controllers without making any change to database? Thanks.

Answer 1

You don't have standard primary key id, so you will have to specify all the keys in the relationship (idCar).
Car model
public function user() {
return $this->belongsTo(User::class, 'idUser', 'idCar');
}
But this will get you $car->user which is the owner of the car.
With the way you designed your database, a user can have many cars.
User model
public function cars() {
return $this->hasMany(Car::class, 'idUser', 'idUser');
}
When you want to retrieve the cars belong to a user, you can
$user->cars;
or
foreach($user->cars as $car) {
// $car
}