为什么我之前工作正常却一直收到 'undefined method'？

Question

我的 OrdersController 如下所示，但我不断收到此消息：

#

的未定义方法 `listing_id='

提取的源代码（大约第 31 行）： 29 30 31 @order.listing_id = @listing.id

我是不是做错了什么？我正在按照教程进行操作，然后按照说明进行操作，然后当它不起作用时决定复制和粘贴，但它仍然不起作用。请提供任何帮助。

完整代码如下

    class OrdersController < ApplicationController
       before_action :set_order, only: [:show, :edit, :update, :destroy]
    before_action :authenticate_user!

 def sales
@orders = Order.all.where(seller: current_user).order("created_at DESC")
end

def purchases
@orders = Order.all.where(buyer: current_user).order("created_at DESC")
   end

   # GET /orders/new
     def new
       @order = Order.new
       @listing = Listing.find(params[:listing_id])
     end



  # POST /orders
  # POST /orders.json

def create
@order = Order.new(order_params)
@listing = Listing.find(params[:listing_id])
@seller = @listing.user


@order.listing_id = @listing.id
@order.buyer_id = current_user.id
@order.seller_id = @seller.id

 Stripe.api_key = ENV["STRIPE_API_KEY"]
token = params[:stripeToken]

begin
  charge = Stripe::Charge.create(
    :amount => (@listing.price * 100).floor,
    :currency => "usd",
    :card => token
    )
  flash[:notice] = "Thanks for ordering!"
rescue Stripe::CardError => e
  flash[:danger] = e.message
end

respond_to do |format|
  if @order.save
    format.html { redirect_to root_url, notice: 'Order was successfully created.' }
    format.json { render action: 'show', status: :created, location: @order }
  else
    format.html { render action: 'new' }
    format.json { render json: @order.errors, status: :unprocessable_entity }
  end
end
      end

      private
        # Use callbacks to share common setup or constraints between actions.
def set_order
    @order = Order.find(params[:id])
end

# Never trust parameters from the scary internet, only allow the white list through.
def order_params
  params.require(:order).permit(:address, :city, :state)
end
    end

Answer 1

定义强参数：

def order_params
  params.require(:order).permit(:address, :city, :state, :listing_id, :buyer_id, :seller_id  )
end

Answer 2

检查订单模型的字段。您是否将 listing_id 作为订单 table 的一列？检查迁移文件以确保您已将 "listing_id" 字段添加到 "orders" table.

为什么我之前工作正常却一直收到 'undefined method'？

Why do I keep getting 'undefined method' when it's worked fine before?

ruby

controller

ruby-on-rails

ruby-on-rails-4