# NameError in AdminController#index building scaffold **URL:** \ **Category:** Rails\ **Created:** [August 17, 2006, 2:37pm UTC](https://www.ruby-forum.com/t/nameerror-in-admincontroller-index-building-scaffold/65312 "2006-08-17T14:37:58Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![jameslabocki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ad7895/32.png) [@jameslabocki](https://www.ruby-forum.com/u/jameslabocki)\ **Post date:** [August 17, 2006, 2:37pm UTC](https://www.ruby-forum.com/t/nameerror-in-admincontroller-index-building-scaffold/65312/1 "2006-08-17T14:37:58Z")
I’m a pretty big newbie with ROR, but when following a tutorial I encounter an ugly error when building a scaffold. Here is my environment Dev system: - Windows XP - java version “1.5.0\_06” - MySQL java version “1.5.0\_06” - Ruby 1.8.4 - Ruby Gems 0.9.0 - Gem install mysql Successfully installed mysql-2.7.1-mswin32 Installing ri documentation for mysql-2.7.1-mswin32… Installing RDoc documentation for mysql-2.7.1-mswin32… - Table in ediweb database mysql\> desc users; ±---------------±------------±-----±----±--------±---------------+ | Field | Type | Null | Key | Default | Extra | ±---------------±------------±-----±----±--------±---------------+ | user\_id | int(11) | NO | PRI | NULL | auto\_increment | | user\_login | varchar(50) | NO | | | | | user\_firstname | varchar(50) | NO | | | | | user\_lastname | varchar(50) | NO | | | | | user\_role | varchar(50) | NO | | | | ±---------------±------------±-----±----±--------±---------------+ 5 rows in set (0.18 sec) I am also connecting to Subversion on a linux system as my Repo. When I start my server I am able to view several other controllers. I stop my server and create a scaffold in RadRails. ediweb\> ruby script/generate scaffold Users Admin exists app/controllers/ exists app/helpers/ exists app/views/admin exists test/functional/ dependency model exists app/models/ exists test/unit/ exists test/fixtures/ create app/models/users.rb create test/unit/users\_test.rb create test/fixtures/users.yml identical app/views/admin/\_form.rhtml create app/views/admin/list.rhtml create app/views/admin/show.rhtml create app/views/admin/new.rhtml create app/views/admin/edit.rhtml create app/controllers/admin\_controller.rb create test/functional/admin\_controller\_test.rb create app/helpers/admin\_helper.rb create app/views/layouts/admin.rhtml create public/stylesheets/scaffold.css Looks like no problem, but then I check the page: NameError in AdminController#index uninitialized constant User RAILS\_ROOT: ./script/…/config/… Application Trace | Framework Trace | Full Trace D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/dependencies.rb:123:in `const_missing' D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:131:in`const\_missing’ D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/inflector.rb:161:in `constantize' D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/core_ext/string/inflections.rb:59:in`constantize’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/pagination.rb:194:in `paginator_and_collection_for' D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/pagination.rb:129:in`paginate’ #{RAILS\_ROOT}/app/controllers/admin\_controller.rb:12:in `list' #{RAILS_ROOT}/app/controllers/admin_controller.rb:3:in`index’ -e:4 D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/dependencies.rb:123:in `const_missing' D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:131:in`const\_missing’ D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/inflector.rb:161:in `constantize' D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/core_ext/string/inflections.rb:59:in`constantize’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/pagination.rb:194:in `paginator_and_collection_for' D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/pagination.rb:129:in`paginate’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/base.rb:941:in `perform_action_without_filters' D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/filters.rb:368:in`perform\_action\_without\_benchmark’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/benchmarking.rb:69:in `perform_action_without_rescue' D:/ruby/lib/ruby/1.8/benchmark.rb:293:in`measure’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/benchmarking.rb:69:in `perform_action_without_rescue' D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/rescue.rb:82:in`perform\_action’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/base.rb:408:in `process_without_filters' D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/filters.rb:377:in`process\_without\_session\_management\_support’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/session\_management.rb:117:in `process' D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/dispatcher.rb:38:in`dispatch’ D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/webrick\_server.rb:115:in `handle_dispatch' D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/webrick_server.rb:81:in`service’ D:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service' D:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in`run’ D:/ruby/lib/ruby/1.8/webrick/server.rb:173:in `start_thread' D:/ruby/lib/ruby/1.8/webrick/server.rb:162:in`start\_thread’ D:/ruby/lib/ruby/1.8/webrick/server.rb:95:in `start' D:/ruby/lib/ruby/1.8/webrick/server.rb:92:in`start’ D:/ruby/lib/ruby/1.8/webrick/server.rb:23:in `start' D:/ruby/lib/ruby/1.8/webrick/server.rb:82:in`start’ D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/webrick\_server.rb:67:in `dispatch' D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/commands/servers/webrick.rb:59 D:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in`require’ D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/dependencies.rb:147:in `require' D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/commands/server.rb:30 D:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in`require’ D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/dependencies.rb:147:in `require’ script/server:3 D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/dependencies.rb:123:in `const_missing' D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:131:in`const\_missing’ D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/inflector.rb:161:in `constantize' D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/core_ext/string/inflections.rb:59:in`constantize’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/pagination.rb:194:in `paginator_and_collection_for' D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/pagination.rb:129:in`paginate’ #{RAILS\_ROOT}/app/controllers/admin\_controller.rb:12:in `list' #{RAILS_ROOT}/app/controllers/admin_controller.rb:3:in`index’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/base.rb:941:in `perform_action_without_filters' D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/filters.rb:368:in`perform\_action\_without\_benchmark’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/benchmarking.rb:69:in `perform_action_without_rescue' D:/ruby/lib/ruby/1.8/benchmark.rb:293:in`measure’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/benchmarking.rb:69:in `perform_action_without_rescue' D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/rescue.rb:82:in`perform\_action’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/base.rb:408:in `process_without_filters' D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/filters.rb:377:in`process\_without\_session\_management\_support’ D:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action\_controller/session\_management.rb:117:in `process' D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/dispatcher.rb:38:in`dispatch’ D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/webrick\_server.rb:115:in `handle_dispatch' D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/webrick_server.rb:81:in`service’ D:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service' D:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in`run’ D:/ruby/lib/ruby/1.8/webrick/server.rb:173:in `start_thread' D:/ruby/lib/ruby/1.8/webrick/server.rb:162:in`start\_thread’ D:/ruby/lib/ruby/1.8/webrick/server.rb:95:in `start' D:/ruby/lib/ruby/1.8/webrick/server.rb:92:in`start’ D:/ruby/lib/ruby/1.8/webrick/server.rb:23:in `start' D:/ruby/lib/ruby/1.8/webrick/server.rb:82:in`start’ D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/webrick\_server.rb:67:in `dispatch' D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/commands/servers/webrick.rb:59 D:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in`require’ D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/dependencies.rb:147:in `require' D:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/commands/server.rb:30 D:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in`require’ D:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active\_support/dependencies.rb:147:in `require’ script/server:3 -e:4 This error occured while loading the following files: user.rb Request Parameters: None Show session dump * * * flash: !map:ActionController::Flash::FlashHash {} Response Headers: {“cookie”=\>[], “Cache-Control”=\>“no-cache”} I have tried building the scaffold with users and admin instead of Users and Admin, but it’s still not working! Also, I verified MySQL connectivity from ruby server to the database by doing the following: ActiveRecord::Base.connection.select\_all(‘desc users’) =\> [{“Extra”=\>“auto\_increment”, “Default”=\>nil, “Null”=\>“NO”, “Type”=\>“int(11)”, “Field”=\>“user\_id”, “Key”=\>“PRI”}, {“Extra”=\>"", “Default”=\>"", “Null”=\>“NO”, “Type”=\>“varchar(50)”, “Field”=\>“user\_login”, “Key”=\>""}, {“Extra”=\>"", “Default”=\>"", “Null”=\>“NO”, “Type”=\>“varchar(50)”, “Field”=\>“user\_firstname”, “Key”=\>""}, {“Extra”=\>"", “Default”=\>"", “Null”=\>“NO”, “Type”=\>“varchar(50)”, “Field”=\>“user\_lastname”, “Key”=\>""}, {“Extra”=\>"", “Default”=\>"", “Null”=\>“NO”, “Type”=\>“varchar(50)”, “Field”=\>“user\_role”, “Key”=\>""}] > > ActiveRecord::Base.connection.select\_all(‘select \* from users’) > > ActiveRecord::Base.connection.select\_all(‘select \* from users’) > > =\> [] My question is I do have one record in the table but the ‘select \*’ query doesn’t come back with nothing. Any help would be appreciated! 🙂 Thanks James ---
**Author:** ![jameslabocki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ad7895/32.png) [@jameslabocki](https://www.ruby-forum.com/u/jameslabocki)\ **Post date:** [August 17, 2006, 2:46pm UTC](https://www.ruby-forum.com/t/nameerror-in-admincontroller-index-building-scaffold/65312/2 "2006-08-17T14:46:42Z")
One more note, I didn’t have any records in the database! When I inserted some I am still able to connect through the development console – but still gettig the same error from the [http://localhost:3000/admin](http://localhost:3000/admin) — any ideas? > > ActiveRecord::Base.connection.select\_all(‘select\* from users’) > > ActiveRecord::Base.connection.select\_all(‘select\* from users’) > > =\> [{“user\_login”=\>“jsmith”, “user\_firstname”=\>“joe”, “user\_id”=\>“1”, > > “user\_role”=\>“admin”, “user\_lastname”=\>“smith”}, > > {“user\_login”=\>“bsmith”, “user\_firstname”=\>“bob”, “user\_id”=\>“2”, > > “user\_role”=\>“user”, “user\_lastname”=\>“smith”}] ---
**Author:** ![jameslabocki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ad7895/32.png) [@jameslabocki](https://www.ruby-forum.com/u/jameslabocki)\ **Post date:** [August 17, 2006, 2:38pm UTC](https://www.ruby-forum.com/t/nameerror-in-admincontroller-index-building-scaffold/65312/3 "2006-08-17T14:38:54Z")
I forgot by database.yml has the following for the dev environment: development: adapter: mysql database: ediweb username: root password: \*\*\*\*\*\*\*\* host: localhost ---
**Author:** ![jameslabocki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ad7895/32.png) [@jameslabocki](https://www.ruby-forum.com/u/jameslabocki)\ **Post date:** [August 17, 2006, 2:54pm UTC](https://www.ruby-forum.com/t/nameerror-in-admincontroller-index-building-scaffold/65312/4 "2006-08-17T14:54:17Z")
Also, my model users.rb: class Users \< ActiveRecord::Base end ---
**Author:** ![jameslabocki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ad7895/32.png) [@jameslabocki](https://www.ruby-forum.com/u/jameslabocki)\ **Post date:** [August 17, 2006, 3:11pm UTC](https://www.ruby-forum.com/t/nameerror-in-admincontroller-index-building-scaffold/65312/5 "2006-08-17T15:11:44Z")
I was able to solve my own problem. I generated the scaffold using ‘ruby script/generate scaffold user Admin’ ediweb\> ruby script/generate scaffold user Admin exists app/controllers/ exists app/helpers/ exists app/views/admin exists test/functional/ dependency model exists app/models/ exists test/unit/ exists test/fixtures/ create app/models/user.rb create test/unit/user\_test.rb create test/fixtures/users.yml create app/views/admin/\_form.rhtml create app/views/admin/list.rhtml create app/views/admin/show.rhtml create app/views/admin/new.rhtml create app/views/admin/edit.rhtml create app/controllers/admin\_controller.rb create test/functional/admin\_controller\_test.rb create app/helpers/admin\_helper.rb create app/views/layouts/admin.rhtml create public/stylesheets/scaffold.css How did ruby know that my database table was ‘users’ when I generated the scaffold as ‘user’? I’m sorry if this is a dumb question 🙂 ---
**Author:** ![jameslabocki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ad7895/32.png) [@jameslabocki](https://www.ruby-forum.com/u/jameslabocki)\ **Post date:** [August 17, 2006, 4:20pm UTC](https://www.ruby-forum.com/t/nameerror-in-admincontroller-index-building-scaffold/65312/6 "2006-08-17T16:20:24Z")
Unless you change it, it always looks for the plural form of the model as the table… so a “person” model would have a “people” table, “cat” model would have “cats” table, etc. This is pretty basic and covered in “Agile Web D. in Rails” as well as a lot of online tutorials. ---
**Author:** ![jameslabocki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ad7895/32.png) [@jameslabocki](https://www.ruby-forum.com/u/jameslabocki)\ **Post date:** [August 18, 2006, 1:45pm UTC](https://www.ruby-forum.com/t/nameerror-in-admincontroller-index-building-scaffold/65312/7 "2006-08-18T13:45:05Z")
I figured it out – I had to remove the mysql gem. gem uninstall mysql Everything worked after that!