Question

我有一个Order / LineItem类型的应用程序，它将Order及其关联的行项目插入到数据库中。创建订单后（after_create）然后我调用一个更新Order表中的totals字段的函数。但是，当它运行时，它还会对所有行项目运行更新查询，并且因为paper_trail处于活动状态：update，所以它也会导致插入新版本。问题是，可能有数百个订单项（目前最大的是872个），所以很明显这不是很优化，而且由于纸质跟踪，我们会得到不必要的版本。

我看过：触摸符号，但这似乎只适用于孩子＆gt;父母而非父母＆gt;子。

有没有办法在更新其父项时停止对订单项触发更新？

以下是精简控制器/模型。

OrdersController：

class OrdersController < ApplicationController

def create
    @order = Order.new(order_params)

    if @order.save
       render :json => @order, :serializer => ::OrderSerializer
    end
end

订单型号：

class Order < ActiveRecord::Base
    has_paper_trail
    belongs_to :customer
    has_many :line_items, :dependent => :destroy

    after_create :update_total_quantities

    accepts_nested_attributes_for :line_items

    def update_total_quantities
       update_attributes({:total_quantity => calculated_total_quantity})
    end
end

LineItem模型：

class LineItem < ActiveRecord::Base
   has_paper_trail :on => [:update, :destroy]   

   belongs_to :order 
end

日志中的问题示例：

INSERT INTO "line_items" ("colour", "created_at", "order_id", "price", "product_id", "quantity", "size", "updated_at", "variant_id") VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9) RETURNING "id"[0m  [["colour", 2], ["created_at", Wed, 08 Jan 2014 11:47:38 UTC +00:00], ["order_id", 1216], ["price", 77.0], ["product_id", 241702], ["quantity", 1], ["size", "18"], ["updated_at", Wed, 08 Jan 2014 11:47:38 UTC+00:00], ["variant_id", "241702_2_18"]
INSERT INTO "line_items" ("colour", "created_at", "order_id", "price", "product_id", "quantity", "size", "updated_at", "variant_id") VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9) RETURNING "id"  [["colour", 106], ["created_at", Wed, 08 Jan 2014 11:47:38 UTC +00:00], ["order_id", 1216], ["price", 20.0], ["product_id", 2753], ["quantity", 1], ["size", "18"], ["updated_at", Wed, 08 Jan 2014 11:47:38 UTC +00:00], ["variant_id", "2753_106_18"]

UPDATE "orders" SET "total_quantity" = $1, "updated_at" = $2 WHERE "orders"."id" = 1216  [["total_quantity", 878], ["updated_at", Wed, 08 Jan 2014 11:47:40 UTC +00:00]
UPDATE "line_items" SET "created_at" = $1, "updated_at" = $2 WHERE "line_items"."id" = 108533  [["created_at", Wed, 08 Jan 2014 11:47:38 UTC +00:00], ["updated_at", Wed, 08 Jan 2014 11:47:38 UTC +00:00]
UPDATE "line_items" SET "created_at" = $1, "updated_at" = $2 WHERE "line_items"."id" = 108526[0m  [["created_at", Wed, 08 Jan 2014 11:47:38 UTC +00:00], ["updated_at", Wed, 08 Jan 2014 11:47:38 UTC +00:00

Answer 1

我通过更改工作流逻辑来修复此问题。我没有在创建后运行update_total_quantities方法，而是在控制器中运行该方法，因此我更新的代码看起来更像：

OrdersController：

class OrdersController < ApplicationController

def create
  @order = Order.new(order_params)
  @order.total_quantity = @order.calculated_total_quantity

  if @order.save
    render :json => @order, :serializer => ::OrderSerializer
  end
end

订单型号：

class Order < ActiveRecord::Base
  has_paper_trail

  belongs_to :customer
  has_many :line_items, :dependent => :destroy

  accepts_nested_attributes_for :line_items

end

更新父级时停止子模型更新

1 个答案: