的Rails的ActiveRecord的Mysql :: ConnectionNotEstablished

Question

我創建了一個新的Rails應用程序，當我開始服務器試圖連接它給這個服務器

錯誤

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' 

的database.yml

development: 
    adapter: mysql2 
    encoding: utf8 
    database: simple_cms_development 
    pool: 5 
    username: root 
    password: root 
    host: 127.0.0.1 

Mysql正在運行，密碼正確。我試圖從命令行連接

G:\simple_cms>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> 

誰能告訴我什麼可能是該錯誤

Answer 1

可能的原因有一個在你的/etc/mysql/my.cnf併爲您的綁定地址mysql deamon。它可能不綁定到任何IP。然後它將使用unix套接字，這是快速的IP連接，...

綁定地址的選項名稱是綁定地址如果不匹配它不會綁定到任何地址。還要看看指定unix套接字路徑的套接字。您可以使用這樣的插座在你的database.yml

development: 
    adapter: mysql2 
    encoding: utf8 
    database: simple_cms_development 
    username: root 
    password: root 
    host: 127.0.0.1 
    pool: 5 
    socket: /path/to/the/socket/mysql.sock 

這應該爲你做，