has_many 与总活跃记录

class Product < ActiveRecord::Base

      belongs_to  :category
      has_many  :order_items, dependent: :destroy
    end


class OrderItem < ActiveRecord::Base
  belongs_to :order
  belongs_to :product
end

我需要列出所有产品及其 order_item 的数量总和及其总价格总和

Product
id    name
1    product_1

OrderItem
product_id order_id quantity total_price
 1            1      10        200
 1            2      10        200

for example expecting output should be
name       quantity   total_price
product_1  20         400

select p.name, sum(o.quantity) as quantity, sum(o.total_price) as total_price
from Product p
  join OrderItem o on p.id = o.product_id
group by p.name