ruby-on-rails - Ruby Rails 数据库

Question

我是 Rails 的新手，我已经开始开发我的第一个应用程序，但我遇到了无法解决的问题。

基本上我在跟踪出租属性(property)，所以我有房屋、租户、租赁、供应商、维修等的 Controller 和模型。我已经能够设置所有这些并创建新记录、更新、编辑等，来自网络表单，除了一个名为 TENANTS 的表单。

由于我无法从 Web 表单获取应用程序的保存记录 - 我转到 Rails 控制台并遇到了同样的问题。我无法从控制台保存到数据库。

我在控制台中创建新“租户”记录的示例

 tenant = Tenant.new
=> #<Tenant id: nil, first_name: nil, last_name: nil, home_id: nil, created_at: nil, updated_at: nil>
>> first_name = "Billy"
=> "Billy"
>> last_name = "Jones"
=> "Jones"
>> tenant.save
   (0.1ms)  BEGIN
  SQL (0.2ms)  INSERT INTO `tenants` (`created_at`, `first_name`, `home_id`, `last_name`,          `updated_at`) VALUES ('2012-07-29 20:54:28', NULL, NULL, NULL, '2012-07-29 20:54:28')`  
Mysql2::Error: Column 'first_name' cannot be null: INSERT INTO `tenants` (`created_at`, `first_name`, `home_id`, `last_name`, `updated_at`) VALUES ('2012-07-29 20:54:28', NULL, NULL, NULL, '2012-07-29 20:54:28')
   (0.1ms)  ROLLBACK
ActiveRecord::StatementInvalid: Mysql2::Error: Column 'first_name' cannot be null: INSERT INTO `tenants` (`created_at`, `first_name`, `home_id`, `last_name`, `updated_at`) VALUES ('2012-07-29 20:54:28', NULL, NULL, NULL, '2012-07-29 20:54:28')

SO, I cannot determine the problem.  It says first_name cannot be null, obviously because I setup the database that way, but there is a value trying to go into database, even though I can return a value in Rails Console asking for first_name.....  Any advise?


Below are controller/model



***** TENANT CONTROLLER
class TenantsController < ApplicationController

    def index
        render('list')
    end

    def list
      @tenants = Tenant.order("tenants.last_name ASC")
    end

    def show
      @tenant = Tenant.find(params[:id])
    end

    def new
      @tenant = Tenant.new
    end

    def create
        @tenant = Tenant.new(params[:tenant])
        @tenant.save

        if @tenant.save
            flash[:notice] = "New Tenant was created successfully."
            redirect_to(:action => 'list')
        else
            render('new')
        end
    end

    def edit
      @tenant = Tenant.find(params[:id])

    end


    def update
        # find object using form parameters
        @tenant = Tenant.find(params[:id])

        #update the object
        if @tenant.update_attributes(params[:tenant])

            #if update succeeds redirect to
            flash[:notice] = "Tenant was updated successfully."
            redirect_to(:action => 'show', :id => @tenant.id)
            else
            render('edit')
        end

    end

    def delete
        @tenant = Tenant.find(params[:id])

    end

    def destroy
        @tenant = Tenant.find(params[:id])
        @tenant.destroy

        flash[:notice] = "Tenant was destroyed successfully."
        redirect_to(:action => 'list' )

    end


end

***** TENANT MODEL
class Tenant < ActiveRecord::Base
    attr_accessible :first_name, :last_name, :home_id
end

Answer 1

在你的console您永远不会分配的 session first_name或 last_name到您通过 Tenant.new 实例化的租户记录- 所以它当然是空的。试试这个；

tenant = Tenant.new
=> #<Tenant id: nil, first_name: nil, last_name: nil, home_id: nil, created_at: nil, updated_at: nil>
>> tenant.first_name = "Billy"
=> "Billy"
>> tenant.last_name = "Jones"
=> "Jones"
>> tenant.save

您可以通过在一行中指定名称来简化这一过程，也可以使用 create尝试立即保存到数据库:

tenant = Tenant.create(:first_name => "Billy", :last_name => "Jones")