Requesting solution for laravel 8 project - laravel

Question

I'm an elementary web developer, I'm facing a problem. Please help me solve this. I'm creating both row and column dynamic. for save() is fine. But for update, only name is updated and other item
quantities cannot. Here is my codes.
//for save()
public function stockAdd(Request $request)
{
$validator = validator(request()->all(), ['stock_name' => 'required']);
if($validator->fails()) {
return back()->withErrors($validator);
}
$user_id = Auth::user()->user_id;
$stock_id = random_int(100000, 999999);
$stocks = new Stocks();
$stocks->stock_id = $stock_id;
$stocks->owner_id = $user_id;
$stocks->stock_name = request()->stock_name;
$stocks->my_stock = 0;
$stocks->disable = 0;
$stocks->save();
$brands = Brands::all();
$products = Products::all();
foreach ($brands as $brand){
foreach ($products as $product){
if($product['brand_id'] == $brand['id']){
$product_id = $product->product_id;
$stockitems = new StockItems();
$stockitems->stock_id = $stock_id;
$stockitems->product_id = $product->product_id;
$stockitems->owner_id = $user_id;
if(request()->$product_id > 0){
$stockitems->count = request()->$product_id;
}else{
$stockitems->count = 0;
}
$stockitems->save();
}
}
}
return redirect()->back()->with('successAddMsg','Successfully Added');
}
//for update()
public function stockUpdate(Request $request, $id)
{
$validator = validator(request()->all(), ['stock_name' => 'required']);
if($validator->fails()) {
return back()->withErrors($validator);
}
$stock = Stocks::findOrFail($id);
$stock->stock_name = request()->stock_name;
$stock->my_stock = 0;
$stock->disable = 0;
$stock->update();
$brands = Brands::all();
$products = Products::all();
foreach ($brands as $brand){
foreach ($products as $product){
if($product['brand_id'] == $brand['id']){
$product_id = $product->product_id;
//dd($product_id);
$stockitemitems = DB::table("stock_items")->select("*")->where("owner_id",Auth::user()->user_id)->where("stock_id",$stock->stock_id)->get();
$stockitems->count = $request->input($product_id);
$stockitems->update();
}
}
}
return redirect(route('user.stock-list'))->with('successAddMsg','Successfully Added');
}
The problem shows like this "Creating default object from empty value"