model add scope

app/models/product.rb

@@ -2,7 +2,7 @@
 class Product < ActiveRecord::Base
     has_paper_trail
     self.table_name = 'products'
-    devise_for :admins
+    devise :admins
 
     #Thread.current[:current_user] = @current_user
     scope :active, -> { where(ptype: "cent_sale") }