Php and Laravel prevent duplicate entries help please

[PNewCode]

Hello everyone.

I am wanting to prevent duplicate entries. This task is using laravel which I know little to nothing about. I'm putting this in PHP help because the file has php at the top of it. If this is the wrong place for this, then I apologize.

The issue is that I googled for days and either I can't find the answer, or I can't translate what I find to fit what I need to do.
The goal here is to prevent new users that sign up, to choose a username or screen name that already exists. I'm putting the code down below that I have to register the new users.
The reason for this is because lately, I've had too many people replicating the same user names to make new accounts, either because they don't feel like asking for help when they forget the password or because they don't remember the answer to the question they created, or because they think making a new account gets them something new.

So what I want to do is prevent duplicate user and screen names

This laravel stuff is so far over my head that it's like trying to translate ancient egyptian cymbals for me. It took me over a week just to find where this file was haha
Andy and all help is appreciated greatly

NOTE: I didn't try to add any code to it yet because I'm incredibly nervous to destroy what is built because I don't understand this at all.

<?php

namespace App\Http\Controllers\Auth;

use App\Models\User;
use Illuminate\Http\Request;
use Illuminate\Http\JsonResponse;
use App\Http\Controllers\Controller;
use App\Services\ImageUploadService;
use Illuminate\Support\Facades\Hash;
use Illuminate\Auth\Events\Registered;
use App\Providers\RouteServiceProvider;
use Illuminate\Support\Facades\Validator;
use Illuminate\Foundation\Auth\RegistersUsers;

class RegisterController extends Controller
{
    /*
    |--------------------------------------------------------------------------
    | Register Controller
    |--------------------------------------------------------------------------
    |
    | This controller handles the registration of new users as well as their
    | validation and creation. By default this controller uses a trait to
    | provide this functionality without requiring any additional code.
    |
    */

    use RegistersUsers;

    /**
     * Where to redirect users after registration.
     *
     * @var string
     */
    protected $redirectTo = RouteServiceProvider::HOME;

    /**
     * Create a new controller instance.
     *
     * @return void
     */
    public function __construct()
    {
        $this->middleware('guest');
    }

    /**
     * Get a validator for an incoming registration request.
     *
     * @param  array  $data
     * @return \Illuminate\Contracts\Validation\Validator
     */
    protected function validator(array $data)
    {
        return Validator::make($data, [
			'fname' => ['required', 'string', 'max:255', 'alpha'],
        'username' => ['required', 'string', 'max:255', 'alpha_num'],
            //'lname' => ['required', 'string', 'max:255'],
            'password' => ['required', 'string', 'min:8'],
            'image' => ['image', 'mimes:jpg,jpeg,png','mimetypes:image/jpg,image/jpeg,image/png'],
            'question' => ['required', 'string', 'max:255'],
            'answer' => ['required', 'string', 'max:255'],
            'ip_address' => ['required', 'string', 'max:255'],
        ]);
    }

    /**
     * Create a new user instance after a valid registration.
     *
     * @param  array  $data
     * @return \App\Models\User
     */
    protected function create(array $data)
    {
		
        return User::create([
            'fname' => $data['fname'],
            //'lname' => $data['lname'],
            'email' => $data['username'],
            'question' => $data['question'],
            'answer' => $data['answer'],
            'password' => Hash::make($data['password']),
            'unique_id' => rand(time(), 100000000),
			'ip_address' => $data['ip_address'], // Save the user's IP address
        ]);
    }

    /**
     * Handle a registration request for the application.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\RedirectResponse|\Illuminate\Http\JsonResponse
     */
    public function register(Request $request)
    {
        $this->validator($request->all())->validate();

        $user = $this->create($request->all());
        event(new Registered($user));

        /*$filename = now().$request->file('image')->getClientOriginalName();
        $request->image->storeAs('images',$filename,'public');*/
		
        //$filename =  (new ImageUploadService())->upload($request->file('image'), 'images');

        //$user->update(['img'=>$filename]);

        $users = User::where('id','!=',$user->id)->get()->modelKeys();
        foreach($users as $u){
            $user->conversations()->create()->users()->attach($u);
        }

        $this->guard()->login($user);

        if ($response = $this->registered($request, $user)) {
            return $response;
        }

        return $request->wantsJson()
                    ? new JsonResponse([], 201)
                    : redirect('login.php');
                    //: redirect($this->redirectPath());
    }
}

 

Edited October 10 by PNewCode

[Barand]

The best way is to define the username as a unique key in your user table. That way you can't add another with the same name (an exception with be thrown if you attempt to add a second).

Then check for duplicate key errors when adding users in you code.

[PNewCode]

43 minutes ago, Barand said:

The best way is to define the username as a unique key in your user table.

Thank you. The column name is "fname". Is that what you mean? In regular php I know how to check for duplicates and list them but thats as far as my knowledge goes. Laravel is a wild mess to me haha

[Barand]

The basic code is

    /*   Current user data
            +----+----------+--------------+
            | id | username | fullname     |
            +----+----------+--------------+
            | 1  | lucy     | Lucy Lastik  |
            | 2  | hugh     | Hugh Jass    |
            | 3  | tom      | Tom DiCanari |
            +----+----------+--------------+
    */
    
    try {
        $stmt = $pdo->prepare("INSERT INTO user (username, fullname)    
                               VALUES (?, ?)
                               ");
        $stmt->execute( [ 'lucy', 'Lucy Smith' ] );                       // attempt duplicate insert
    }
    catch (PDOException $e) {
        if ($stmt->errorInfo()[1] == 1062)  {                             // duplicate key error code
            $_SESSION['errors']['username'] = 'username already exists';  // error message to display to user when form redisplayed
        }                                                                   
        else throw $e;                                                    // let php handle the error
    }

Just convert it to Laravelese.

[maxxd]

Even better, Laravel will throw an Illuminate\Database\UniqueConstraintViolationException when you try to insert a record that violates the SQL unique constraint. Just catch that before the PDOException or general Exception and you can handle it.

Looking at your code, you don't have a username column in your create method. The POST['username'] field is assigned to the email column in the table, which is a bit confusing. Either way, heed Barand's advice to add a unique constraint on whatever your username column is, wrap your create() statement in a try...catch() that catches the UniqueConstraintViolationException, and make sure your create() method is inserting data into that column.