电子商务购物车在laravel中一次又一次地添加相同的产品ID

Question

I have three products in my products table.

ID- 11, 12 and 13

But when I am trying to add all the three products into cart, only id-13 product is being added without quantity increment. Cant add product 11 and 12. Please help me with the code.

Here is my CartController-

public function store(Request $request)
    {

        if (Auth::check()) {

            $cart = new Cart;

            if($cart->product_id == $request->product_id){
                $cart->increment('product_id');
            }
            else{
                $cart->user_id = Auth::id();
                $cart->product_id = $request->product_id;
                $cart->save();
            

            session()->flash('success', 'Product has added to cart !!');
            return back();
            }
        }
    }

Here is addtocart.blade.php -

<form action="{{route('cart.store')}}" method="post">
@csrf
@foreach($products as $product)
    <input type="hidden" name="product_id" value="{{$product->id}}">
    @endforeach
  <button type="submit" class="btn btn-light">Add to cart</button>
</form>

Here is my cart table image - Cart table

Please help.

Answer 1

First you need to check the rows of the cart table try this

$cartRow = Cart::where('user_id',Auth::id())->where('product_id',$request->product_id)->first();
if($cartRow){
    $cartRow->increment('product_quantity');
}else{
    Cart::create(['user_id'=>Auth::id(),'product_id'=>$request->product_id]);
}

Answer 2

The first problem is that you're creating 3 different input elements with the same name, so only one of the values is being taken. An alternative could be create radio buttons:

<form action="{{route('cart.store')}}" method="post">
    @csrf
    @foreach($products as $product)
        <input type="radio" name="product_id" value="{{$product->id}}">
        <label>Product {{$product->id}}</label>
    @endforeach
    <button type="submit" class="btn btn-light">Add to cart</button>
</form>

This way only one id will be sent to your controller (the one selected).

The other problem is in your controller, you're creating a new instance of cart with every call, so there won't be any increment,

$cart = Cart::where('user_id',Auth::id())
    ->where('product_id',$request->product_id)
    ->first();

Then you can increment if $cart exists or create a new record

if($cart){
    $cart->increment('product_quantity');
    $cart->save();
}else{
    Cart::create([
        'user_id' => Auth::id(),
        'product_id' => $request->product_id
    ]);
}

Answer 3

So it worked. Removed foreach loop from addtocart.blade.php as it is partially included to products.blade.php.

Before -

<form action="{{route('cart.store',$product->id)}}" method="post">
@csrf
  @foreach($products as $product)
    <input type="id" name="product_id" value="{{$product->id}}">
   @endforeach 
  <button type="submit" class="btn btn-light">Add to cart</button>
  
</form>

Before image

After -

<form action="{{route('cart.store',$product->id)}}" method="post">
@csrf
    <input type="id" name="product_id" value="{{$product->id}}">
  <button type="submit" class="btn btn-light">Add to cart</button>
  
</form>

After image