收到此错误找不到'id'= 1的帖子

Question

I have been working on Ruby on Rails app but When i visit http://localhost:3000/posts/2/reviews/new I get this error ' Couldn't find Post with 'id'=2 '. I have nested the reviews inside the posts resources and assigned the post_id to 2 but when i want to write a new review i get the error above. i couldn't find whats the issue here.

reviews_controller.rb

class ReviewsController < ApplicationController
  before_action :set_review, only: [ :edit, :update, :destroy]
  before_action :set_post
  before_action :authenticate_user!

  respond_to :html



  def new
    @review = Review.new
    respond_with(@review)
  end

  def edit
  end

  def create
    @review = Review.new(review_params)
    @review.user_id = current_user.id
    @review.post_id = @post.id
    @review.save
    redirect_to root_path


  end

  def update
    @review.update(review_params)
    respond_with(@review)
  end

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

  private
    def set_review
      @review = Review.find(params[:id])
    end

    def set_post
      @post = Post.find(params[:post_id])
    end

    def review_params
      params.require(:review).permit(:comment)
    end
end

routes.rb

Rails.application.routes.draw do

  devise_for :users
    resources :posts do
    resources :reviews , except: [:show,:index]
end
  get 'pages/help'

  get 'pages/blog'

  get 'pages/contact'

  resources :posts
  root 'posts#index'
end

posts_controller.rb

class PostsController < ApplicationController
  before_action :set_post, only: [:show, :edit, :update, :destroy]

  # GET /posts
  # GET /posts.json
  def index
    @posts = Post.all
  end

  # GET /posts/1
  # GET /posts/1.json
  def show
  end

  # GET /posts/new
  def new
    @post = Post.new
  end

  # GET /posts/1/edit
  def edit
  end

  # POST /posts
  # POST /posts.json
  def create
    @post = Post.new(post_params)

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

  # PATCH/PUT /posts/1
  # PATCH/PUT /posts/1.json
  def update
    respond_to do |format|
      if @post.update(post_params)
        format.html { redirect_to @post, notice: 'Post was successfully updated.' }
        format.json { render :show, status: :ok, location: @post }
      else
        format.html { render :edit }
        format.json { render json: @post.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /posts/1
  # DELETE /posts/1.json
  def destroy
    @post.destroy
    respond_to do |format|
      format.html { redirect_to posts_url, notice: 'Post was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

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

    # Never trust parameters from the scary internet, only allow the white list through.
    def post_params
      params.require(:post).permit(:title, :description)
    end
end

Answer 1

This is simply means that you database doesn't contain Post with an id of 2, i guess you created it and then destroy it with your scaffold controller.

what you can do to resolve it, add to your set_post (change it to get_post to apply better naming) method under ReviewsController :

def set_post    
  unless @post = Post.where(id: params[:post_id]).first
    redirect_to posts_path, flash: {alert: "Post doesn't exists"}
  end
end

You can also perform any action instead of show Warn like show 404 page.