How to create an invitation system in Laravel PHP - laravel

Question

Im new in laravel and I'm watching a youtube playlist to build my 1st project....
now I'm trying to implement an inv only system
so the register form looks like
username:
inv code:
password:
I've already created a migration which has
user_id - this is user id of the user who created the invite
code - the code which will get validated at time of registration and then deleted
{timestamps}
so the issue im having is:
how do I verify that the invite entered by user exists in the table "inv_codes" and matches the column "code" and then delete it after registration is complete
here is a minimal reproducible example
lass RegisterController extends Controller
{
public function __construct()
{
$this->middleware(['guest']);
}
public function index()
{
return view('auth.register');
}
public function submit(Request $request)
{
$this->validate($request, [
'username' => 'required|max:6',
'password' => 'required',
]);
User::create([
'username' => $request->username,
'password' => Hash::make($request->password),
]);
auth()->attempt($request->only('username', 'password'));
return redirect()->route('dashboard');
}
}

Answer 1

Suppose that you have code column in both users and inv_codes tables. Now during registration, you can use validation. Something like this:
$request->validate([
'code' => 'required|exists:inv_codes,code',
// ... rest of registration fields
]);
Then you can delete that row in inv_codes table by something like this:
You can read more at: https://laravel.com/docs/8.x/validation#quick-writing-the-validation-logic
DB::table('inv_codes')->where('code', $request->code)->delete();
You can read more at: https://laravel.com/docs/8.x/queries#delete-statements

Answer 2

Ideally you would create a table to hold the invitations and an accompanying Eloquent model. On register, you can check if the invitation code the user entered is valid by using a couple of ways.
Manually
Invitation::where('code', request()->inv_code)->firstOrFail();
Validation
request()->validate([
'inv_code' => ['exists:inv_codes,code'],
]);
In either case, you need to fetch the invitation and then delete it after registering the user.
$invitation->delete();