ActiveResource Update Operation ::无法批量分配受保护的属性：created_at，id，updated_at

Question

当我尝试更新并保存ActiveResource时，我收到以下错误。

在控制台上

> m = Machine.first
 => #<Machine:0xb07a0d4 @attributes={"created_at"=>"2013-04-22T09:13:56Z", "id"=>1, "name"=>"laptop", "updated_at"=>"2013-04-22T09:13:56Z"}, @prefix_options={}, @persisted=true>

> m.name = 'mouse'
 => "mouse"

> m.save
ActiveResource::ServerError: Failed.  Response code = 500.  Response message = Internal Server Error

服务器上的

ActiveModel::MassAssignmentSecurity::Error (Can't mass-assign protected attributes: created_at, id, updated_at):
  app/controllers/machines_controller.rb:62:in `block in update'
  app/controllers/machines_controller.rb:61:in `update'

这是ActiveResource模型

class Machine < ActiveResource::Base
  self.site = 'http://localhost:3000'
end

这是ActiveRecord模型

class Machine < ActiveRecord::Base
  attr_accessible :name
end