如何将数据从在 rails 中嵌套值的 json 哈希保存到数据库

Question

>从数据库to_json呈现数据效果很好

def getOrderDetails
    #To get the details of a particular guest_order and its batches and items
    @guest_order = GuestOrder.find(params[:id])
    render json: @guest_order.to_json(except: [:created_at, :updated_at], 
            include: {order_batches: {except: [:guest_order_id, :created_at, :updated_at], 
            include: {order_items: {except: [:order_batch_id, :created_at, :updated_at] } }
                }
              }
            )
  end

但是，如何将相同表的数据保存到数据库中。参数为

Parameters: {"guestOrder"=>"{"GuestOrder"{"GuestOrderId":1,
"orderTime":"2012-04-25 18:28:30","notes":"spicy","userId":14,"tableId":1,
"batch":[{"items":[{"itemId":1,"quantity":4,"dishId":1},
{"itemId":2,"quantity":4,"dishId":3},
{"itemId":3,"quantity":3,"dishId":6}],
"placed":"2012-04-25 18:28:30","batchId":1}],
"numberOfAdults":1,"numberOfChilderns":3}}"} 

我已经像这样解析了参数值，

def guestOrder
    guest_order = JSON.parse(params["guestOrder"])
    # How to store the values from guest_order to database tables
end
    1.9.2p290 :002 > guestOrder = JSON.parse("{"GuestOrder"{"GuestOrderId":1,
"orderTime":"2012-04-25 18:28:30","notes":"spicy","userId":14,"tableId":1,
"batch":[{"items":[{"itemId":1,"quantity":4,"dishId":1},
{"itemId":2,"quantity":4,"dishId":3},
{"itemId":3,"quantity":3,"dishId":6}],
"placed":"2012-04-25 18:28:30","batchId":1}],
"numberOfAdults":1,"numberOfChilderns":3}}")

 => {"GuestOrder"=>{"GuestOrderId"=>1, "orderTime"=>"2012-04-25 18:28:30", "notes"=>"spicy", 
"userId"=>14, "tableId"=>1, "batch"=>[{"items"=>[{"itemId"=>1, "quantity"=>4, "dishId"=>1}, 
{"itemId"=>2, "quantity"=>4, "dishId"=>3}, {"itemId"=>3, "quantity"=>3, "dishId"=>6}], 
"placed"=>"2012-04-25 18:28:30", "batchId"=>1}], "numberOfAdults"=>1, 
"numberOfChilderns"=>3}} 

在这里，guest_orders有很多order_batches，order_batches有很多order_items

# == Schema Information
#
# Table name: guest_orders
#
#  GuestOrderId   :integer         not null, primary key
#  adults         :integer
#  children       :integer
#  orderTime      :datetime
#  tableId        :integer
#
# Table name: order_batches
#
#  batchId        :integer         not null, primary key
#  placed         :datetime
#  guest_order_id :integer
#
# Table name: order_items
#
#  itemId         :integer         not null, primary key
#  quantity       :integer
#  dishId         :integer
#  order_batch_id :integer

Answer 1

在

模型中使用带有列名的"serialize"关键字来保存json数据。

例如：列名在模型中json_data

serialize :json_data

然后在您的控制器中使用，

@model_obj.json_data = {:company => { :name => "IBM", :place => "US" }, :employee => {:name => "Mohan", :address => "US"}}

然后保存对象

Answer 2

你绝对应该看看accept_nested_attributes_for ActiveRecord 方法http://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html 还有一篇关于它的Railscasts的coupole：http://railscasts.com/episodes?utf8=%E2%9C%93&search=nested+forms

因此，在您的GuestOrder模型中，应该有这样的内容：

accepts_nested_attributes_for :order_batches

在你的参数中order_batches属性应该包含在单独的哈希中，如下所示：

"order_batches_attributes" => {"0" => {"placed" => "false"}, "1" => {"placed" => "true"}}

如果属性有效order_batches将自动保存在数据库中，并带有正确的 GuestOrderId。

Answer 3

  def guestOrder
    guest_order = JSON.parse(params["guestOrder"])["GuestOrder"]
    placed_at = Time.zone.parse(guest_order["orderTime"])
    @order = GuestOrder.new(placed: placed_at, guest_table_id: guest_order["tableId"], user_id: guest_order["userId"], 
            adults: guest_order["numberOfAdults"], children: guest_order["numberOfChilderns"], notes: guest_order["notes"])
    guest_order["batch"].each do |batch|
      placed = Time.zone.parse(batch["placed"])
      @batch = OrderBatch.new(placed: placed)
      batch["items"].each do |item| 
        @batch.order_items << OrderItem.new(dish_id: item["dishId"], quantity: item["quantity"]) 
      end 
      @batch.guest_order = @order
      @batch.save 
    end
    if @order.save 
      render json: @order.to_json(only: [:id], message: "success") 
    else 
      render json: @order.errors 
    end  
  end