correct validation for creating and editing product

app/Http/Controllers/ProductController.php

@@ -71,6 +71,10 @@ class ProductController extends Controller
 //            'price' => 'required'
 //        ]));
 
+        request()->validate([
+            'reference' => 'unique:products,reference'
+        ]);
+
         Product::create($this->validateProduct());
 
         return redirect('/');
@@ -150,7 +154,7 @@ class ProductController extends Controller
     public function validateProduct()
     {
         return request()->validate([
-            'reference' => 'required|unique:products,reference',
+            'reference' => 'required',
             'description_short' => 'required',
             'description_long' => 'required',
             'price' => 'required',