rails 找不到 database.yml答案

【问题标题】：rails can't find database.ymlrails 找不到 database.yml
【发布时间】：2011-06-21 03:49:42
【问题描述】：

我刚刚删除了我的database.yml，因为我正在尝试使用 Mongoid，现在我得到了以下信息：

$ rails server           
=> Booting WEBrick
=> Rails 3.0.9 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/application/configuration.rb:88:in `read': No such file or directory - /home/chris-kun/code/thirsty/config/database.yml (Errno::ENOENT)
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/application/configuration.rb:88:in `database_configuration'
        from /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.9/lib/active_record/railtie.rb:58:in `block (2 levels) in <class:Railtie>'
        from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.0.9/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
        from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.0.9/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
        from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.0.9/lib/active_support/lazy_load_hooks.rb:26:in `on_load'
        from /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.9/lib/active_record/railtie.rb:57:in `block in <class:Railtie>'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/initializable.rb:25:in `instance_exec'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/initializable.rb:25:in `run'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/initializable.rb:50:in `block in run_initializers'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/initializable.rb:49:in `each'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/initializable.rb:49:in `run_initializers'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/application.rb:134:in `initialize!'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/application.rb:77:in `method_missing'
        from /home/chris-kun/code/thirsty/config/environment.rb:5:in `<top (required)>'
        from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:239:in `require'
        from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:239:in `block in require'
        from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:225:in `block in load_dependency'
        from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:596:in `new_constants_in'
        from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:225:in `load_dependency'
        from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:239:in `require'
        from /home/chris-kun/code/thirsty/config.ru:3:in `block in <main>'
        from /usr/lib/ruby/gems/1.9.1/gems/rack-1.2.3/lib/rack/builder.rb:46:in `instance_eval'
        from /usr/lib/ruby/gems/1.9.1/gems/rack-1.2.3/lib/rack/builder.rb:46:in `initialize'
        from /home/chris-kun/code/thirsty/config.ru:1:in `new'
        from /home/chris-kun/code/thirsty/config.ru:1:in `<main>'
        from /usr/lib/ruby/gems/1.9.1/gems/rack-1.2.3/lib/rack/builder.rb:35:in `eval'
        from /usr/lib/ruby/gems/1.9.1/gems/rack-1.2.3/lib/rack/builder.rb:35:in `parse_file'
        from /usr/lib/ruby/gems/1.9.1/gems/rack-1.2.3/lib/rack/server.rb:162:in `app'
        from /usr/lib/ruby/gems/1.9.1/gems/rack-1.2.3/lib/rack/server.rb:253:in `wrapped_app'
  1 #!/usr/bin/env ruby
        from /usr/lib/ruby/gems/1.9.1/gems/rack-1.2.3/lib/rack/server.rb:204:in `start'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/commands/server.rb:65:in `start'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/commands.rb:30:in `block in <top (required)>'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/commands.rb:27:in `tap'
        from /usr/lib/ruby/gems/1.9.1/gems/railties-3.0.9/lib/rails/commands.rb:27:in `<top (required)>'
        from script/rails:6:in `require'
        from script/rails:6:in `<main>'

有什么想法吗？

【问题讨论】：

标签： ruby-on-rails mongoid

【解决方案1】：

在config/application.rb 中，删除require 'rails/all' 行并替换为：

require "rails"

%w(
  action_controller
  action_mailer
  active_resource
  rails/test_unit
).each do |framework|
  begin
    require "#{framework}/railtie"
  rescue LoadError
  end
end

（这是 railties gem 中 rails/all.rb 的内容，但删除了 activerecord 行）。

【讨论】：

【解决方案2】：

我之前遇到过类似的问题，但事实证明我有一些分散的 active_record 引用。这要归功于 Dylan Markow！

Removing database.yml when using Mongoid in Rails 3.2

执行grep -r active_record config/ 查找所有引用，然后将它们注释掉！

【讨论】：

【解决方案3】：

对于那些想要使用 db 相关功能 ex) rake db:seed 与 mongoid 的人，还可以添加 mongoid railtie：

https://github.com/mongodb/mongoid/tree/master/lib/mongoid/railties

require "rails"

# Import gems in Gemfile
Bundler.require(*Rails.groups)

# important that this is imported after gems in Gemfile are imported
%w(
  mongoid
  action_controller
  action_mailer
  active_resource
  rails/test_unit
).each do |framework|
begin
  require "#{framework}/railtie"
    rescue LoadError
  end
end

【讨论】：

【解决方案4】：

Rails 5 和所有未来版本的 Rails 的更新答案：

您应该使用rails/all.rb 文件中的require sn-p，该文件与您的Rails 版本一致，没有active_record railtie。 Here is a link to rails/all.rb on the Rails master branch.

在撰写本文时，它包括许多您不想错过的新铁路：

require "rails"

%w(
  action_controller/railtie
  action_view/railtie
  action_mailer/railtie
  active_job/railtie
  action_cable/engine
  rails/test_unit/railtie
  sprockets/railtie
).each do |railtie|
  begin
    require railtie
  rescue LoadError
  end
end

【讨论】：