title: Rails Mysql ActiveRecord::ConnectionNotEstablished
body: <p>I created a new rails application, when i started server an tried to connect it gave this server</p>
  
  <p><strong>error</strong></p>
  
  <pre><code>activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:546:in `retrieve_connection'
  activerecord (4.0.0) lib/active_record/connection_handling.rb:79:in `retrieve_connection'
  activerecord (4.0.0) lib/active_record/connection_handling.rb:53:in `connection'
  activerecord (4.0.0) lib/active_record/query_cache.rb:51:in `restore_query_cache_settings'
  activerecord (4.0.0) lib/active_record/query_cache.rb:43:in `rescue in call'
  activerecord (4.0.0) lib/active_record/query_cache.rb:32:in `call'
  activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call'
  activerecord (4.0.0) lib/active_record/migration.rb:369:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
  activesupport (4.0.0) lib/active_support/callbacks.rb:373:in `_run__713349442__call__callbacks'
  activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
  actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/reloader.rb:64:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
  railties (4.0.0) lib/rails/rack/logger.rb:38:in `call_app'
  railties (4.0.0) lib/rails/rack/logger.rb:21:in `block in call'
  activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `block in tagged'
  activesupport (4.0.0) lib/active_support/tagged_logging.rb:25:in `tagged'
  activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `tagged'
  railties (4.0.0) lib/rails/rack/logger.rb:21:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
  rack (1.5.5) lib/rack/methodoverride.rb:21:in `call'
  rack (1.5.5) lib/rack/runtime.rb:17:in `call'
  activesupport (4.0.0) lib/active_support/cache/strategy/local_cache.rb:83:in `call'
  rack (1.5.5) lib/rack/lock.rb:17:in `call'
  actionpack (4.0.0) lib/action_dispatch/middleware/static.rb:64:in `call'
  railties (4.0.0) lib/rails/engine.rb:511:in `call'
  railties (4.0.0) lib/rails/application.rb:97:in `call'
  rack (1.5.5) lib/rack/lock.rb:17:in `call'
  rack (1.5.5) lib/rack/content_length.rb:14:in `call'
  rack (1.5.5) lib/rack/handler/webrick.rb:60:in `service'
  C:/Ruby23/lib/ruby/2.3.0/webrick/httpserver.rb:140:in `service'
  C:/Ruby23/lib/ruby/2.3.0/webrick/httpserver.rb:96:in `run'
  C:/Ruby23/lib/ruby/2.3.0/webrick/server.rb:296:in `block in start_thread'
  </code></pre>
  
  <p><strong>database.yml</strong></p>
  
  <pre><code>development:
    adapter: mysql2
    encoding: utf8
    database: simple_cms_development
    pool: 5
    username: root
    password: root
    host: 127.0.0.1
  </code></pre>
  
  <p>Mysql is running and the password is correct. I tried connecting from command line</p>
  
  <pre><code>G:\simple_cms&gt;mysql -uroot -proot simple_cms_development
  Warning: Using a password on the command line interface can be insecure.
  Welcome to the MySQL monitor.  Commands end with ; or \g.
  Your MySQL connection id is 7
  Server version: 5.6.21 MySQL Community Server (GPL)
  
  Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
  
  Oracle is a registered trademark of Oracle Corporation and/or its
  affiliates. Other names may be trademarks of their respective
  owners.
  
  Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
  
  mysql&gt;
  </code></pre>
  
  <p>Can someone tell me what might be the possible cause for that error</p>