Rails s错误：`method_missing'：未定义方法`active_record'。

Question

Rails s错误：`method_missing'：未定义方法`active_record'。

ruby-on-railsundefinedrails-activerecord

3

我的Rails项目以前都能正常工作。我因为删除了MySQL及其相关组件而遇到了这个错误。然后我重新安装了MySQL，却得到了同样的错误。接着我又重新安装了Ruby和Rails，但是错误仍然存在。在使用 "rails new myapp"，"bundle install"，"rails s" 后，我得到了下面的错误：

=> Booting WEBrick
=> Rails 4.0.2 application starting in development on 

=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
Exiting
**/home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configuration.rb:95:in `method_missing': undefined method `active_record' for #<Rails::Application::Configuration:0x0000000303cae8> (NoMethodError)
    from /home/cwu/Dropbox/project/web/atop/config/environments/development.rb:23:in `block in <top (required)>'**
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configurable.rb:24:in `class_eval'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configurable.rb:24:in `configure'
    from /home/cwu/Dropbox/project/web/atop/config/environments/development.rb:1:in `<top (required)>'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `require'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `block in require'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:214:in `load_dependency'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `require'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/engine.rb:591:in `block (2 levels) in <class:Engine>'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/engine.rb:590:in `each'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/engine.rb:590:in `block in <class:Engine>'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:30:in `instance_exec'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:30:in `run'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:226:in `block in tsort_each'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:348:in `block (2 levels) in each_strongly_connected_component'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:418:in `block (2 levels) in each_strongly_connected_component_from'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:427:in `each_strongly_connected_component_from'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:417:in `block in each_strongly_connected_component_from'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:44:in `each'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:44:in `tsort_each_child'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:411:in `call'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:411:in `each_strongly_connected_component_from'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:347:in `block in each_strongly_connected_component'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:345:in `each'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:345:in `call'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:345:in `each_strongly_connected_component'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:224:in `tsort_each'
    from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:205:in `tsort_each'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:54:in `run_initializers'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/application.rb:215:in `initialize!'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configurable.rb:30:in `method_missing'
    from /home/cwu/Dropbox/project/web/atop/config/environment.rb:5:in `<top (required)>'
    from /home/cwu/Dropbox/project/web/atop/config.ru:3:in `require'
    from /home/cwu/Dropbox/project/web/atop/config.ru:3:in `block in <main>'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
    from /home/cwu/Dropbox/project/web/atop/config.ru:in `new'
    from /home/cwu/Dropbox/project/web/atop/config.ru:in `<main>'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:49:in `eval'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:49:in `new_from_string'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:40:in `parse_file'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/server.rb:277:in `build_app_and_options_from_config'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/server.rb:199:in `app'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands/server.rb:48:in `app'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/server.rb:314:in `wrapped_app'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands/server.rb:75:in `start'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:76:in `block in <top (required)>'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `tap'
    from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

- Roy

5个回答

3

Leedy Liu 在某种程度上是正确的，但如果您在创建新的Rails应用程序时遇到此错误，则表明您的环境存在更深层次的问题。

根据这个回答，您可能在application.rb文件中注释掉了require "active_record/railtie"。请检查并确保没有这种情况发生。

您可能需要重新安装带有ActiveRecord的Rails，以确保功能与您的应用程序一起恢复。您尝试过这个吗？

gem install bundler
gem install rails
bundle install

除此之外，您需要确保正确安装了Ruby on Rails。您正在运行什么环境？Linux还是Windows？

- Richard Peck

相同的错误。/home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configuration.rb:95:in method_missing': undefined method active_record' for #Rails::Application::Configuration:0x000000044dd6f0 (NoMethodError) from /home/cwu/Dropbox/project/web/myapp/config/envir - Roy

好的，在这个编辑器之后。我的新创建的（rails new myapp）可以工作了。我的旧应用程序有相同的错误。 - Roy

2

作为一般性的修复方法，删除所有对active_record的引用。最简单的方法是在"active_records"的根目录上进行查找，在config/application.rb和config/environments/development以及production.rb中找到所有的用法，并将其删除。

- Tyler

0

尝试：

    'gem install bundler'

然后：
运行 'bundle install'。
再观察是否能解决问题。

- Snyderman

0

在config/application.rb中注释掉config.active_record.raise_in_transactional_callbacks = true，并在config/environments/development.rb中设置config.active_record.migration_error = :page_load。

- rplaurindo

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- Dangyi Liu · Accepted Answer

错误很明显，即在config/environments/development.rb:23中配置了未加载的active_record。只需删除即可。

config.active_record.migration_error = :page_load

一切都会好的。