我的Rails环境是
Rails：3.2.14，
ruby：1.9.3，
系统：Ubuntu
mysql：5.5.32-0ubuntu0.12.04.1
我创建了一个mysql数据库，为了测试数据库，我从windows.so中的mysql工作台连接它，我想证明，我在ubuntu中的mysql数据库运行正确
但是，当我在浏览器中运行网站时，我得到错误：active record：：connectionnotestablished .
完整的跟踪是：

activerecord (3.2.14) lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrieve_connection'
activerecord (3.2.14) lib/active_record/connection_adapters/abstract/connection_specification.rb:171:in `retrieve_connection'
activerecord (3.2.14) lib/active_record/connection_adapters/abstract/connection_specification.rb:145:in `connection'
activerecord (3.2.14) lib/active_record/query_cache.rb:67:in `rescue in call'
activerecord (3.2.14) lib/active_record/query_cache.rb:61:in `call'
activerecord (3.2.14) lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call'
actionpack (3.2.14) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (3.2.14) lib/active_support/callbacks.rb:405:in `_run__72338529__call__445636797__callbacks'
activesupport (3.2.14) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.14) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
activesupport (3.2.14) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.14) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (3.2.14) lib/action_dispatch/middleware/reloader.rb:65:in `call'
actionpack (3.2.14) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
actionpack (3.2.14) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
actionpack (3.2.14) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
railties (3.2.14) lib/rails/rack/logger.rb:32:in `call_app'
railties (3.2.14) lib/rails/rack/logger.rb:16:in `block in call'
activesupport (3.2.14) lib/active_support/tagged_logging.rb:22:in `tagged'
railties (3.2.14) lib/rails/rack/logger.rb:16:in `call'
actionpack (3.2.14) lib/action_dispatch/middleware/request_id.rb:22:in `call'
rack (1.4.5) lib/rack/methodoverride.rb:21:in `call'
rack (1.4.5) lib/rack/runtime.rb:17:in `call'
activesupport (3.2.14) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.4.5) lib/rack/lock.rb:15:in `call'
actionpack (3.2.14) lib/action_dispatch/middleware/static.rb:63:in `call'
railties (3.2.14) lib/rails/engine.rb:484:in `call'
railties (3.2.14) lib/rails/application.rb:231:in `call'
rack (1.4.5) lib/rack/content_length.rb:14:in `call'
railties (3.2.14) lib/rails/rack/log_tailer.rb:17:in `call'
rack (1.4.5) lib/rack/handler/webrick.rb:59:in `service'
/home/hxh/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service'
/home/hxh/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run'
/home/hxh/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'

我的database.yml是：

development:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  database: r4rmusic_development
  pool: 5
  username: root
  password:123 
  host:127.0.0.1
  socket: /var/run/mysqld/mysqld.sock

我的Gemfile是：

source 'https://rubygems.org'
gem 'rails', '3.2.14'
gem 'mysql2'

group :assets do
  gem 'sass-rails',   '~> 3.2.3'
  gem 'coffee-rails', '~> 3.2.1' 

  gem 'uglifier', '>= 1.0.3'
end

gem 'jquery-rails'

请帮我