scaffold问题？

AEoCROMq

在学习ruby on rails中，我遇到很多scaffold问题，不知道怎么解决，还请高手帮忙？
NoMethodError in AdminController#index
undefined method `scaffold' for AdminController:Class
RAILS_ROOT: C:/Documents and Settings/Administrator/work/depot

Application Trace | Framework Trace | Full Trace

代码：
class CreateProducts < ActiveRecord::Migration
  def self.up
    create_table :products do |t|
            t.column :title,       :string
            t.column :description, :text
            t.column :image_url,   :string

      
    end
  end

  def self.down
    drop_table :products
  end
end
controller中代码：
class AdminController < ApplicationController
scaffold :product
end