没有路由匹配“/admin”错误

Question

我正在用 Rails 编写我的第一个应用程序，这就是我所做的

C:\Personal\rails\demo>ruby -v
    ruby 1.9.2p136 (2010-12-25) [i386-mingw32]

C:\Personal\rails\demo>rails -v
    Rails 3.0.5

C:\Personal\rails\demo>rails generate model book
      invoke  active_record
      create    db/migrate/20110325190010_create_books.rb
      create    app/models/book.rb
      invoke    test_unit
      create      test/unit/book_test.rb
      create      test/fixtures/books.yml

C:\Personal\rails\demo>rake db:migrate
(in C:/Personal/rails/demo)
==  CreateBooks: migrating ====================================================
-- create_table(:books)
   -> 0.0000s
==  CreateBooks: migrated (0.0000s) ===========================================


C:\Personal\rails\demo>rails generate controller admin
      create  app/controllers/admin_controller.rb
      invoke  erb
      create    app/views/admin
      invoke  test_unit
      create    test/functional/admin_controller_test.rb
      invoke  helper
      create    app/helpers/admin_helper.rb
      invoke    test_unit
      create      test/unit/helpers/admin_helper_test.rb

然后我编辑了 admin_controller.rb 如下：

class AdminController < ApplicationController
    scaffold :book
end

这是 routes.rb 文件

Demo::Application.routes.draw do
  # The priority is based upon order of creation:
  # first created -> highest priority.

  # Sample of regular route:
  #   match 'products/:id' => 'catalog#view'
  # Keep in mind you can assign values other than :controller and :action

  # Sample of named route:
  #   match 'products/:id/purchase' => 'catalog#purchase', :as => :purchase
  # This route can be invoked with purchase_url(:id => product.id)

  # Sample resource route (maps HTTP verbs to controller actions automatically):
  #   resources :products

  # Sample resource route with options:
  #   resources :products do
  #     member do
  #       get 'short'
  #       post 'toggle'
  #     end
  #
  #     collection do
  #       get 'sold'
  #     end
  #   end

  # Sample resource route with sub-resources:
  #   resources :products do
  #     resources :comments, :sales
  #     resource :seller
  #   end

  # Sample resource route with more complex sub-resources
  #   resources :products do
  #     resources :comments
  #     resources :sales do
  #       get 'recent', :on => :collection
  #     end
  #   end

  # Sample resource route within a namespace:
  #   namespace :admin do
  #     # Directs /admin/products/* to Admin::ProductsController
  #     # (app/controllers/admin/products_controller.rb)
  #     resources :products
  #   end

  # You can have the root of your site routed with "root"
  # just remember to delete public/index.html.
  # root :to => "welcome#index"

  # See how all your routes lay out with "rake routes"

  # This is a legacy wild controller route that's not recommended for RESTful applications.
  # Note: This route will make all actions in every controller accessible via GET requests.
  # match ':controller(/:action(/:id(.:format)))'
end

但是，当我转到 http://localhost:3000/admin 时，我收到“没有路由匹配“/admin””错误。我注意到我的 routes.rb 只有注释行。我是不是做错了什么？

Answer 1

你还没有为管理员添加路由，为什么你的所有路由都被注释掉了。

如果管理员是一个资源添加这一行

resources :admin

在您的控制器中，您还需要一个索引方法和索引视图文件，因为http://localhost:3000/admin 会带您到那里

Answer 2

尝试从这一行删除评论：

match ':controller(/:action(/:id(.:format)))'

Answer 3

注意：此答案适用于满足上述几点但您仍然看到此错误的情况。是 Rails 3.2 和 Ruby 2.3.8

---

问题定义：

我使用管理员凭据成功登录。当页面登陆/admin 时，我看到了No route matches [GET] "/admin" 错误页面。我到处碰头，用了我所有的知识。此外，生成的路由和grep，但没有发布admin 路由。

$ rake routes | grep admin

但只发布了设计相关的管理路线。然后我阅读了关于我后来注意到的路线的警告，就像

ActiveAdmin: ActiveAdmin::DatabaseHitDuringLoad: Your file, app/admin/account_tags.rb (line 4), 
caused a database error while Active Admin was loading. This is most common 
when your database is missing or doesn't have the latest migrations applied. 
To prevent this error, move the code to a place where it will only be run 
when a page is rendered. One solution can be, to wrap the query in a Proc.
Original error message: PG::UndefinedTable: ERROR:  relation "account_tags" does not exist

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解决方案

我运行rake db:migrate 并重新启动服务器，问题就消失了。