为什么我不能在RoR中回送来自db的信息？

Question

我有一个名为“ order”的表，其中有许多“ order_items”，每个“ order_items”都属于“ order”和“ product”。 在数据库中，我按顺序有一条记录。 记录是这样的：

订单表：id = 1名称=客户

并且order_items表是这样的：id = 1 product_id = 233 order_id = 1

id = 2 product_id = 454 order_id = 1

我正在尝试使用此代码显示顺序，但未成功：

<% semantic_form_for @order do |f| %>  
  <% f.inputs do %>  
    <%= f.input :name %>  

  <% end %>  
  <%= f.buttons %>  
<% end %>

这是我的order.rb：

class Order < ActiveRecord::Base
  has_many :order_items



end

最后但并非最不重要的是，这是order.rb的控制器：

class OrderController < ApplicationController
  # GET /orders
  # GET /orders.xml
  def index
    @orders = order.all

    respond_to do |format|
      format.html # index.html.erb
      format.xml  { render :xml => @orders }
    end
  end

  # GET /orders/1
  # GET /orders/1.xml
  def show
    @order = order.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.xml  { render :xml => @order }
    end
  end

  # GET /orders/new
  # GET /orders/new.xml
  def new
    @order = order.new

    respond_to do |format|
      format.html # new.html.erb
      format.xml  { render :xml => @order }
    end
  end

  # GET /orders/1/edit
  def edit
    @order = order.find(params[:id])
  end

  # POST /orders
  # POST /orders.xml
  def create
    @order = order.new(params[:order])

    respond_to do |format|
      if @order.save
        flash[:notice] = 'order was successfully created.'
        format.html { redirect_to(@order) }
        format.xml  { render :xml => @order, :status => :created, :location => @order }
      else
        format.html { render :action => "new" }
        format.xml  { render :xml => @order.errors, :status => :unprocessable_entity }
      end
    end
  end

  # PUT /orders/1
  # PUT /orders/1.xml
  def update
    @order = order.find(params[:id])

    respond_to do |format|
      if @order.update_attributes(params[:order])
        flash[:notice] = 'order was successfully updated.'
        format.html { redirect_to(@order) }
        format.xml  { head :ok }
      else
        format.html { render :action => "edit" }
        format.xml  { render :xml => @order.errors, :status => :unprocessable_entity }
      end
    end
  end

  # DELETE /orders/1
  # DELETE /orders/1.xml
  def destroy
    @order = order.find(params[:id])
    @order.destroy

    respond_to do |format|
      format.html { redirect_to(orders_url) }
      format.xml  { head :ok }
    end
  end
end

这是来自RoR的错误：

称为id的nil，错误地为4-如果您确实想要nil的id，请使用object_id

Answer 1

红宝石类必须大写：

Order # class
order # variable or method

这应该工作：

class OrderController < ApplicationController
  def show
    @order = Order.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.xml  { render :xml => @order }
    end
  end
  # ...
end

在您的show.html.erb中：

#...
<%= @order.name =>
#...

网址：

/orders/:id

如果需要，我们可以说一个标准的编辑表单：

# edit.html.erb

<% form_for @order do |f| %>  
  <%= f.input :name %>   
  # fields
  <%= f.submit "Place order" %>  
<% end %>