limiting user to only select items on laravel listbox - laravel

Question

I would like to ask for help, please advise how to solve such problems in laravel
how to make an application like a vehicle ticket application, to limit if there are 5 people on car A, then user can not choose car A in listbox (item listbox carA disable) when booking.
I am confused where to start
I am currently thinking of creating 3 tables
users (id, name,car_id, created_at, updated_at)
cars (id, car_name, created_at, update_at)
I am confused what should be done to the controller Thank you very much
thanks to all of you, i can start the first step.
currently
on the controller
public function create(){
$list=MCars::all();
return view('booking/create')->with('sent_list',$list);
}
on the view
<select name="car" value="{{ old('car')}}">
#foreach($sent_list as $a)
<option value="{{$a->id}}">{{$a->car_name}}</option>
#endforeach
</select>
I want only cars that contain users <5 that appear on the view
maybe i should put this somewhere
SELECT DISTINCT cars.id, cars.car_name, COUNT(users.car_id) from cars INNER JOIN users ON cars.id = users.car_id

Answer 1

The relationship can be like this:
a user belogsTo a car and the car hasMany users
So the Car model class should be:
..
class Car extends Model
{
public function users()
{
return $this->hasMany('App\User');
}
}
And the User model:
class User extends Model
{
public function car()
{
return $this->belongsTo('App\Car');
}
}
Eloquent will automatically determine the proper foreign key. So, here Eloquent will assume the foreign key on the User model is car_id.
Access the collection of users by accessing the users property.
$users = App\Car::find(1)->users;
foreach ($users as $user) {
//
}
In the UserController use:
$user = App\User::find(1);
echo $user->car->name;
This is how the Eloquent works!
Now use the custom logic for limit(5).
To retrieve the number of cars as users:
public function getTotalUsersAttribute()
{
return $this->hasMany('Car')->whereUserId($this->user_id)->count();
}
And:
if(getTotalUsersAttribute() >= 5) {
// dismiss this function with an err msg
}
// otherwise add user to car
Find similar cases and solution from the official docs.

Answer 2

you can make the registration for user, user will insert their name(according to your table), but i'll suggest for inserting new column email and password for login system. if they not login, they cant booked cars. they must register and login to booking cars.
after user login, the car can be booked, you must create form for it. the code something like this
$cars_id = request::get('id');
$total_passenger = DB::table('passenger')->WHERE('car_id',$cars_id);
if(count($data) < 5){
//do insert data into passenger
}else{
//windows alert / whatever
}