无法启动rails服务器Webrick
刚刚开始进入RoR开发，我正在努力让Webrick服务器启动。 我在rails项目的文件夹中。 然后我进入rails server或rails s ，看起来服务器将启动，然后它说下面列出了一堆其他东西Exiting 。 谁知道什么是错的？ 这是终端吐出来的……
wyep:simple_cms designer1$ rails s => Booting WEBrick => Rails 3.2.13 application starting in development on http://0.0.0.0:3000 => Call with -d to detach => Ctrl-C to shutdown server Exiting /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `connect': Access denied for user 'root'@'localhost' (using password: NO) (Mysql2::Error) from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `initialize' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `new' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `mysql2_connection' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:315:in `new_connection' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:325:in `checkout_new_connection' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:247:in `block (2 levels) in checkout' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `loop' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `block in checkout' from /Users/designer1/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:239:in `checkout' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:102:in `block in connection' from /Users/designer1/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:101:in `connection' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrieve_connection' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:171:in `retrieve_connection' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:145:in `connection' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.13/lib/active_record/railtie.rb:88:in `block in ' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `instance_exec' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `run' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/initializable.rb:55:in `block in run_initializers' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `each' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `run_initializers' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/application.rb:136:in `initialize!' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/railtie/configurable.rb:30:in `method_missing' from /Applications/MAMP/htdocs/simple_cms/config/environment.rb:5:in `' from /Applications/MAMP/htdocs/simple_cms/config.ru:3:in `require' from /Applications/MAMP/htdocs/simple_cms/config.ru:3:in `block in ' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize' from /Applications/MAMP/htdocs/simple_cms/config.ru:in `new' from /Applications/MAMP/htdocs/simple_cms/config.ru:in `' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/builder.rb:40:in `eval' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/builder.rb:40:in `parse_file' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/server.rb:200:in `app' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/commands/server.rb:46:in `app' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/server.rb:304:in `wrapped_app' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/server.rb:254:in `start' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/commands/server.rb:70:in `start' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/commands.rb:55:in `block in ' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/commands.rb:50:in `tap' from /Users/designer1/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.13/lib/rails/commands.rb:50:in `' from script/rails:6:in `require' from script/rails:6:in `'
错误在那里的消息：
Access denied for user 'root'@'localhost' (using password: NO) (Mysql2::Error)
在config/database.yml您需要指定有效的host ， user和password