Unknown action No action responded to 2. Actions: show

I'm trying to create a simple RoR application that shows me the
inside my table, provided that it is an example I'm working on the
First Rails" book.

When I try to retrieve the record I get the following message:

"Unknown action

No action responded to 2. Actions: show"

Why am I having that? And, how can I fix this issue?

Provided that:

1- I have inserted one record in the SQLite3 database in the table

2- route.rb

ActionController::Routing::Routes.draw do |map|
map.connect '/ads/id', :controller=>'ads', :action=>'show'
map.connect ':controller/:action/:id'
map.connect ':controller/:action/:id.:format'

3- ads_controller.rb

class AdsController < ApplicationController
def show
@ad = Ad.find(params[:id])

4- show.html.erb

<title><%= @ad.name %></title>
<b>Name: </b><%= @ad. name %>
<b>Description:</b><%= @ad. description %>
<b>Price: </b><%= @ad. price %>
<b>Seller Id: </b><%= @ad. seller_id %>
<b>Email: </b><%= @ad. email %>
<img src="<%= @ad.img_url %>"/>


in routes, delete all, and write

ActionController::Routing::Routes.draw do |map|
  resources :ads

then in console write
rake routes

u will see all routes in your application

than go to

guides.rubyonrails.com and start read it