# Discourse as Your First Rails App

**URL:** <https://meta.discourse.org/t/discourse-as-your-first-rails-app/5751>\
**Category:** Blog\
**Created:** [2013年四月9日 23:08 UTC](https://meta.discourse.org/t/discourse-as-your-first-rails-app/5751 "2013-04-09T23:08:33Z")\
**Posts on this page:** 1\
**Showing post:** 110

<div class="post-metadata">

**Author:** ![Thrillberg](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/thrillberg/32/116889_2.png) [@Thrillberg](https://meta.discourse.org/u/Thrillberg)\
**Post date:** [2015年十月15日 01:02 UTC](https://meta.discourse.org/t/discourse-as-your-first-rails-app/5751/110 "2015-10-15T01:02:40Z")

</div>

I hope my question isn’t silly in some way but I’m having trouble following this how-to. When I attempt `bundle exec rake db:migrate`, I get this error:

```plaintext
rake aborted!
NameError: uninitialized constant SiteSettings::DbProvider::RailsMultisite
/vagrant/lib/site_settings/db_provider.rb:52:in `current_site'
/vagrant/lib/site_setting_extension.rb:44:in `current'
/vagrant/lib/site_setting_extension.rb:96:in `block in setting'
/vagrant/lib/site_setting_extension.rb:93:in `synchronize'
/vagrant/lib/site_setting_extension.rb:93:in `setting'
/vagrant/lib/site_setting_extension.rb:151:in `client_setting'
/vagrant/app/models/site_setting.rb:18:in `block in load_settings'
/vagrant/lib/site_settings/yaml_loader.rb:29:in `block (2 levels) in load'
/vagrant/lib/site_settings/yaml_loader.rb:20:in `each'
/vagrant/lib/site_settings/yaml_loader.rb:20:in `block in load'
/vagrant/lib/site_settings/yaml_loader.rb:19:in `each_key'
/vagrant/lib/site_settings/yaml_loader.rb:19:in `load'
/vagrant/app/models/site_setting.rb:16:in `load_settings'
/vagrant/app/models/site_setting.rb:25:in `<class:SiteSetting>'
/vagrant/app/models/site_setting.rb:4:in `<top (required)>'
/vagrant/config/initializers/04-message_bus.rb:39:in `<top (required)>'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/engine.rb:652:in `block in load_config_initializer'
/var/lib/gems/2.2.0/gems/activesupport-4.2.4/lib/active_support/notifications.rb:166:in `instrument'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/engine.rb:651:in `load_config_initializer'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/engine.rb:616:in `block (2 levels) in <class:Engine>'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/engine.rb:615:in `each'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/engine.rb:615:in `block in <class:Engine>'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/initializable.rb:30:in `instance_exec'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/initializable.rb:30:in `run'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/initializable.rb:55:in `block in run_initializers'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/initializable.rb:44:in `each'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/initializable.rb:44:in `tsort_each_child'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/initializable.rb:54:in `run_initializers'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/application.rb:352:in `initialize!'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/railtie.rb:194:in `public_send'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/railtie.rb:194:in `method_missing'
/vagrant/config/environment.rb:5:in `<top (required)>'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/application.rb:328:in `require_environment!'
/var/lib/gems/2.2.0/gems/railties-4.2.4/lib/rails/application.rb:457:in `block in run_tasks_blocks'
Tasks: TOP => db:migrate => environment
(See full trace by running task with --trace)

```

Can anyone help me?

---

_[View the full topic](https://meta.discourse.org/t/discourse-as-your-first-rails-app/5751)._