未建立连接 - Ruby Rails
Connection Not Enstablished - Ruby on Rails
我对 Rails 上的 Ruby 完全陌生，我正在试一试。
我提前说我没有找到适合我的问题的答案，也没有在 Whosebug 或互联网上找到答案（我尝试了从 SO 和其他网站挑选的很多不同的东西）。
我在 CodeSchool 上关注 Rails for Zombies 2，我需要设置环境才能让事情发生。
为了做到这一点，我遵循 Michael Hartl 的设置阶段
Ruby Rails 教程。
我遵循了每一步，但是，当我想在浏览器中看到："hello, world!" 时，我得到：
ActiveRecord::ConnectionNotEstablished
No connection pool for ActiveRecord::Base
完整跟踪：
activerecord (4.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:566:in `retrieve_connection'
activerecord (4.2.2) lib/active_record/connection_handling.rb:113:in `retrieve_connection'
activerecord (4.2.2) lib/active_record/connection_handling.rb:87:in `connection'
activerecord (4.2.2) lib/active_record/query_cache.rb:51:in `restore_query_cache_settings'
activerecord (4.2.2) lib/active_record/query_cache.rb:43:in `rescue in call'
activerecord (4.2.2) lib/active_record/query_cache.rb:31:in `call'
activerecord (4.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:649:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.2) lib/active_support/callbacks.rb:88:in `call'
activesupport (4.2.2) lib/active_support/callbacks.rb:88:in `_run_callbacks'
activesupport (4.2.2) lib/active_support/callbacks.rb:776:in `_run_call_callbacks'
activesupport (4.2.2) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.2) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
web-console (2.0.0.beta3) lib/action_dispatch/debug_exceptions.rb:18:in `middleware_call'
web-console (2.0.0.beta3) lib/action_dispatch/debug_exceptions.rb:13:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.2) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.2) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.2) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.2) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.2) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.2) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.4) lib/rack/runtime.rb:18:in `call'
activesupport (4.2.2) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/static.rb:113:in `call'
rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
railties (4.2.2) lib/rails/engine.rb:518:in `call'
railties (4.2.2) lib/rails/application.rb:164:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
rack (1.6.4) lib/rack/content_length.rb:15:in `call'
rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
在得到这个之前，我安装了 Rails，我进入了我的 hello_app 文件夹并使用：Bundle Install 然后我只使用了：Rails 服务器。我也按照指南中的说明删除了index.html。
我的 Gemfile:
source 'https://rubygems.org'
gem 'rails', '4.2.2'
gem 'sass-rails', '5.0.2'
gem 'uglifier', '2.5.3'
gem 'coffee-rails', '4.1.0'
gem 'jquery-rails', '>= 3.0.0'
gem 'turbolinks', '2.3.0'
gem 'jbuilder', '2.2.3'
gem 'sdoc', '0.4.0', group: :doc
group :development, :test do
gem 'sqlite3'
gem 'pry-byebug', platform: [:ruby_20]
gem 'web-console', '2.0.0.beta3'
gem 'spring', '1.1.3'
end
我的应用程序控制器：
class ApplicationController < ActionController::Base
protect_from_forgery with: :exception
def hello
render text: "hello, world!"
end
end
我的路线：
HelloApp::Application.routes.draw do
root 'application#hello
end
我的数据库：
development:
adapter: sqlite3
database: db/development.sqlite3
pool: 5
timeout: 5000
test:
adapter: sqlite3
database: db/test.sqlite3
pool: 5
timeout: 5000
production:
adapter: sqlite3
database: db/production.sqlite3
pool: 5
timeout: 5000
如果我的问题是微不足道的，我很抱歉，我也很抱歉我糟糕的英语。
提前致谢！
顺便说一句，您在启动服务器之前 运行 bundle exec rake db:setup 了吗？看起来如果你的数据库还不存在（你可以检查 db/development.sqlite3 文件是否存在）。
我自己解决的。这是由损坏的 Gemfile 引起的问题。
允许我让它工作的正确配置是：
Gemfile:
source 'https://rubygems.org'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.2.2'
# Use sqlite3 as the database for Active Record
gem 'sqlite3'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.1.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby
# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0', group: :doc
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'
# Use Unicorn as the app server
# gem 'unicorn'
# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development
group :development, :test do
# Call 'debugger' anywhere in the code to stop execution and get a debugger console
gem 'debugger'
# Access an IRB console on exception pages or by using <%= console %> in views
gem 'web-console', '~> 2.0'
# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
end
我对 Rails 上的 Ruby 完全陌生，我正在试一试。 我提前说我没有找到适合我的问题的答案，也没有在 Whosebug 或互联网上找到答案（我尝试了从 SO 和其他网站挑选的很多不同的东西）。
我在 CodeSchool 上关注 Rails for Zombies 2，我需要设置环境才能让事情发生。
为了做到这一点，我遵循 Michael Hartl 的设置阶段 Ruby Rails 教程。
我遵循了每一步，但是，当我想在浏览器中看到："hello, world!" 时，我得到：
ActiveRecord::ConnectionNotEstablished
No connection pool for ActiveRecord::Base
完整跟踪：
activerecord (4.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:566:in `retrieve_connection'
activerecord (4.2.2) lib/active_record/connection_handling.rb:113:in `retrieve_connection'
activerecord (4.2.2) lib/active_record/connection_handling.rb:87:in `connection'
activerecord (4.2.2) lib/active_record/query_cache.rb:51:in `restore_query_cache_settings'
activerecord (4.2.2) lib/active_record/query_cache.rb:43:in `rescue in call'
activerecord (4.2.2) lib/active_record/query_cache.rb:31:in `call'
activerecord (4.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:649:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.2) lib/active_support/callbacks.rb:88:in `call'
activesupport (4.2.2) lib/active_support/callbacks.rb:88:in `_run_callbacks'
activesupport (4.2.2) lib/active_support/callbacks.rb:776:in `_run_call_callbacks'
activesupport (4.2.2) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.2) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
web-console (2.0.0.beta3) lib/action_dispatch/debug_exceptions.rb:18:in `middleware_call'
web-console (2.0.0.beta3) lib/action_dispatch/debug_exceptions.rb:13:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.2) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.2) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.2) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.2) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.2) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.2) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.4) lib/rack/runtime.rb:18:in `call'
activesupport (4.2.2) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
actionpack (4.2.2) lib/action_dispatch/middleware/static.rb:113:in `call'
rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
railties (4.2.2) lib/rails/engine.rb:518:in `call'
railties (4.2.2) lib/rails/application.rb:164:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
rack (1.6.4) lib/rack/content_length.rb:15:in `call'
rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
在得到这个之前，我安装了 Rails，我进入了我的 hello_app 文件夹并使用：Bundle Install 然后我只使用了：Rails 服务器。我也按照指南中的说明删除了index.html。
我的 Gemfile:
source 'https://rubygems.org'
gem 'rails', '4.2.2'
gem 'sass-rails', '5.0.2'
gem 'uglifier', '2.5.3'
gem 'coffee-rails', '4.1.0'
gem 'jquery-rails', '>= 3.0.0'
gem 'turbolinks', '2.3.0'
gem 'jbuilder', '2.2.3'
gem 'sdoc', '0.4.0', group: :doc
group :development, :test do
gem 'sqlite3'
gem 'pry-byebug', platform: [:ruby_20]
gem 'web-console', '2.0.0.beta3'
gem 'spring', '1.1.3'
end
我的应用程序控制器：
class ApplicationController < ActionController::Base
protect_from_forgery with: :exception
def hello
render text: "hello, world!"
end
end
我的路线：
HelloApp::Application.routes.draw do
root 'application#hello
end
我的数据库：
development:
adapter: sqlite3
database: db/development.sqlite3
pool: 5
timeout: 5000
test:
adapter: sqlite3
database: db/test.sqlite3
pool: 5
timeout: 5000
production:
adapter: sqlite3
database: db/production.sqlite3
pool: 5
timeout: 5000
如果我的问题是微不足道的，我很抱歉，我也很抱歉我糟糕的英语。
提前致谢！
顺便说一句，您在启动服务器之前 运行 bundle exec rake db:setup 了吗？看起来如果你的数据库还不存在（你可以检查 db/development.sqlite3 文件是否存在）。
我自己解决的。这是由损坏的 Gemfile 引起的问题。 允许我让它工作的正确配置是：
Gemfile:
source 'https://rubygems.org'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.2.2'
# Use sqlite3 as the database for Active Record
gem 'sqlite3'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.1.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby
# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0', group: :doc
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'
# Use Unicorn as the app server
# gem 'unicorn'
# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development
group :development, :test do
# Call 'debugger' anywhere in the code to stop execution and get a debugger console
gem 'debugger'
# Access an IRB console on exception pages or by using <%= console %> in views
gem 'web-console', '~> 2.0'
# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
end