Ruby on rails ActiveRecord:：RecordNotFound无法'；找不到'；id'=新的

在我添加答案之前，它工作正常。我创造的问题没有任何错误，但现在我继续得到这个

找不到id=new的问题

当我创建嵌套资源时，是否把路由弄乱了

Rails.application.routes.draw do  
  devise_for :users
  root 'home#index'
  get '/users/:id' => 'home#profile'
  resources :users
  resources :questions
  resources :answers

  resources :questions do
    resources :answers
  end
end

主计长答覆：

class AnswersController < ApplicationController
  before_action :set_answer, only: [:destroy]

  def create
    @question = Question.find(params[:question_id])
    @answer = @question.answers.create(answer_params)
    @answer.username = current_user.username
    @answer.user_id = current_user.id
    @answer.avatar = current_user.avatar
    @answer.save!
    redirect_to :back
  end

  def destroy
    @answer.destroy
    redirect_to :back
  end

  private

  def set_answer
    @answer = Answer.find(params[:id])
  end

  def answer_params
    params.require(:answer).permit(:body)
  end
end

class QuestionsController < ApplicationController
  before_action :set_question, only: [:show, :edit, :update, :destroy]

  respond_to :html

  def index
    @questions = Question.all
    respond_with(@questions)
  end

  def show
    respond_with(@question)
  end

  def new
    if user_signed_in?
      @question = current_user.questions.build
      respond_with(@question)
    else
      redirect_to new_user_session_path
    end
  end

  def edit
  end

  def create
    @question = current_user.questions.build(question_params)
    if @question.save
      redirect_to question_path(@question)
    else
      render 'new'
    end
  end

  def update
    @question.update(question_params)
    respond_with(@question)
  end

  def destroy
    @question.destroy
    respond_with(@question)
  end

  private
    def set_question
      @question = Question.find(params[:id])
    end

    def question_params
      params.require(:question).permit(:title, :description)
    end
end

完整跟踪：

activerecord (4.1.8) lib/active_record/relation/finder_methods.rb:320:in `raise_record_not_found_exception!'
activerecord (4.1.8) lib/active_record/relation/finder_methods.rb:429:in `find_one'
activerecord (4.1.8) lib/active_record/relation/finder_methods.rb:413:in `find_with_ids'
activerecord (4.1.8) lib/active_record/relation/finder_methods.rb:68:in `find'
C:in `find'
app/controllers/questions_controller.rb:48:in `set_question'
activesupport (4.1.8) lib/active_support/callbacks.rb:424:in `block in make_lambda'
activesupport (4.1.8) lib/active_support/callbacks.rb:143:in `call'
activesupport (4.1.8) lib/active_support/callbacks.rb:143:in `block in halting_and_conditional'
activesupport (4.1.8) lib/active_support/callbacks.rb:229:in `call'
activesupport (4.1.8) lib/active_support/callbacks.rb:229:in `block in halting'
activesupport (4.1.8) lib/active_support/callbacks.rb:149:in `call'
activesupport (4.1.8) lib/active_support/callbacks.rb:149:in `block in halting_and_conditional'
activesupport (4.1.8) lib/active_support/callbacks.rb:229:in `call'
activesupport (4.1.8) lib/active_support/callbacks.rb:229:in `block in halting'
activesupport (4.1.8) lib/active_support/callbacks.rb:166:in `call'
activesupport (4.1.8) lib/active_support/callbacks.rb:166:in `block in halting'
activesupport (4.1.8) lib/active_support/callbacks.rb:166:in `call'
activesupport (4.1.8) lib/active_support/callbacks.rb:166:in `block in halting'
activesupport (4.1.8) lib/active_support/callbacks.rb:166:in `call'
activesupport (4.1.8) lib/active_support/callbacks.rb:166:in `block in halting'
activesupport (4.1.8) lib/active_support/callbacks.rb:86:in `call'
activesupport (4.1.8) lib/active_support/callbacks.rb:86:in `run_callbacks'
actionpack (4.1.8) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.1.8) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.1.8) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.1.8) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.1.8) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.1.8) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.1.8) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.1.8) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
activerecord (4.1.8) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.1.8) lib/abstract_controller/base.rb:136:in `process'
actionview (4.1.8) lib/action_view/rendering.rb:30:in `process'
actionpack (4.1.8) lib/action_controller/metal.rb:196:in `dispatch'
actionpack (4.1.8) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.1.8) lib/action_controller/metal.rb:232:in `block in action'
actionpack (4.1.8) lib/action_dispatch/routing/route_set.rb:82:in `call'
actionpack (4.1.8) lib/action_dispatch/routing/route_set.rb:82:in `dispatch'
actionpack (4.1.8) lib/action_dispatch/routing/route_set.rb:50:in `call'
actionpack (4.1.8) lib/action_dispatch/journey/router.rb:73:in `block in call'
actionpack (4.1.8) lib/action_dispatch/journey/router.rb:59:in `each'
actionpack (4.1.8) lib/action_dispatch/journey/router.rb:59:in `call'
actionpack (4.1.8) lib/action_dispatch/routing/route_set.rb:678:in `call'
warden (1.2.6) lib/warden/manager.rb:35:in `block in call'
warden (1.2.6) lib/warden/manager.rb:34:in `catch'
warden (1.2.6) lib/warden/manager.rb:34:in `call'
rack (1.5.5) lib/rack/etag.rb:23:in `call'
rack (1.5.5) lib/rack/conditionalget.rb:35:in `call'
rack (1.5.5) lib/rack/head.rb:11:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/flash.rb:254:in `call'
rack (1.5.5) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.5.5) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/cookies.rb:560:in `call'
activerecord (4.1.8) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.1.8) lib/active_record/connection_adapters/abstract/connection_pool.rb:621:in `call'
activerecord (4.1.8) lib/active_record/migration.rb:380:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.1.8) lib/active_support/callbacks.rb:82:in `run_callbacks'
actionpack (4.1.8) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.1.8) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.1.8) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.1.8) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.1.8) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.1.8) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.1.8) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.5.5) lib/rack/methodoverride.rb:21:in `call'
rack (1.5.5) lib/rack/runtime.rb:17:in `call'
activesupport (4.1.8) lib/active_support/cache/strategy/local_cache_middleware.rb:26:in `call'
rack (1.5.5) lib/rack/lock.rb:17:in `call'
actionpack (4.1.8) lib/action_dispatch/middleware/static.rb:84:in `call'
rack (1.5.5) lib/rack/sendfile.rb:112:in `call'
railties (4.1.8) lib/rails/engine.rb:514:in `call'
railties (4.1.8) lib/rails/application.rb:144:in `call'
rack (1.5.5) lib/rack/lock.rb:17:in `call'
rack (1.5.5) lib/rack/content_length.rb:14:in `call'
rack (1.5.5) lib/rack/handler/webrick.rb:60:in `service'
C:/RailsInstaller/Ruby2.1.0/lib/ruby/2.1.0/webrick/httpserver.rb:138:in `service'
C:/RailsInstaller/Ruby2.1.0/lib/ruby/2.1.0/webrick/httpserver.rb:94:in `run'
C:/RailsInstaller/Ruby2.1.0/lib/ruby/2.1.0/webrick/server.rb:295:in `block in start_thread'

我相信这跟这条线有关

 def create
  @question = Question.find(params[:question_id])  <==================
  @answer = @question.answers.create(answer_params)
  @answer.username = current_user.username
  @answer.user_id = current_user.id
  @answer.avatar = current_user.avatar
  @answer.save!
  redirect_to :back
end

这将强制您的路径与特定操作关联

把它放在所有嵌套和资源之上
它在这一行

<%= form_for(@question, url: new_question_path, html: { method: :put, :class => 'form-horizontal' }) do |f| %>

正如你所见，这不是你想要返回的路线

假设已经构建了
@question
，但没有保存（就像标准的
/new
请求一样），我认为Rails足够聪明，可以从以下内容中找到您想要的一切：

<%= form_for @question %>

。。。下面是您要更新现有版本的内容：

<%= form_for(@question, url: question_path(@question), html: { method: :put, :class => 'form-horizontal' }) do |f| %>

'form horizontal'}）do | f |%>
我注意到的第一件事是
：问题
和
：答案
都在
routes.rb中定义了两次。如果您想要像
/questions/1/answers/1
@PJSCopeland这样的路由，请尝试取出第一个副本并保留嵌套的资源。我之前尝试过，它通常不起作用，这意味着您在路由中遇到了
/questions/：id
上面的
/questions/new
。您的应用程序将使用
rake routes
中的第一个匹配行解析请求。然而-假设你问的是
GET/questions/new
，那么根据你在这里列出的内容，应该可以解决
questions#new
，所以我想知道你提出的请求是否不那么明显？通常这意味着你最终得到的是/questions/：id上面的/questions/new这正是发生的事情。它正在搜索id=new，而不是转到正常的
new\u question\u路径
。但我真的不知道是什么导致了这个错误。我试图删除额外的重复资源，但仍显示错误。这是否意味着问题超出了路由。rb？如果您告诉我导致错误的请求地址，我将能够跟踪它…进入您的路由并手动键入post'questions/new'=>'questions#new'如果不起作用，您将强制路由与特定操作关联，这是新路由的问题你的控制器内部的操作也不起作用，我正在使用生成的脚手架代码。我没有改变任何东西，有时生成的路由会被现有资源弄乱。嗯，我不确定。希望你能找到答案，祝你好运！等待我想我知道发生了什么。您正在使用一个私有方法来查找您正在创建的问题的ID。这对于更新问题是有意义的，但当您创建新问题时，该ID不存在，因为它会导致您在“questions#new”方法中查找@questions时出错。
<%= form_for(@question, url: new_question_path, html: { method: :put, :class => 'form-horizontal' }) do |f| %>

PUT    /questions/:id(.:format)   questions#update

<%= form_for @question %>

<%= form_for(@question, url: questions_path, html: { method: :post, :class => 'form-horizontal' }) do |f| %>

<%= form_for(@question, url: question_path(@question), html: { method: :put, :class => 'form-horizontal' }) do |f| %>