Ruby on Rails `method_missing': undefined method `active_record' Ruby on Rails中的“method_missing”：未定义方法“active_record”。

Question

运行rails server命令时，我在新创建的rails项目上一直收到以下错误消息。我通过运行命令rails new toy_app来创建它。

请指导我如何解决我的问题。我有另一个rails项目，我可以运行rails server。只是在我的新项目中无法实现。

错误消息：

/Library/Ruby/Gems/2.0.0/gems/railties-4.2.2/lib/rails/railtie/configuration.rb:95:in
`method_missing': undefined method `active_record' for
#<Rails::Application::Configuration:0x007f9413116e40> (NoMethodError)   from /Users/judobear/toy_app/config/application.rb:24:in
`<class:Application>'   from
/Users/judobear/toy_app/config/application.rb:10:in `<module:ToyApp>'
  from /Users/judobear/toy_app/config/application.rb:9:in `<top
(required)>'  from
/Library/Ruby/Gems/2.0.0/gems/railties-4.2.2/lib/rails/commands/commands_tasks.rb:78:in
`require'   from
/Library/Ruby/Gems/2.0.0/gems/railties-4.2.2/lib/rails/commands/commands_tasks.rb:78:in
`block in server'   from
/Library/Ruby/Gems/2.0.0/gems/railties-4.2.2/lib/rails/commands/commands_tasks.rb:75:in
`tap'   from
/Library/Ruby/Gems/2.0.0/gems/railties-4.2.2/lib/rails/commands/commands_tasks.rb:75:in
`server'  from
/Library/Ruby/Gems/2.0.0/gems/railties-4.2.2/lib/rails/commands/commands_tasks.rb:39:in
`run_command!'  from
/Library/Ruby/Gems/2.0.0/gems/railties-4.2.2/lib/rails/commands.rb:17:in
`<top (required)>'  from /Users/judobear/toy_app/bin/rails:8:in
`require'   from /Users/judobear/toy_app/bin/rails:8:in `<top
(required)>'  from
/Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/client/rails.rb:27:in
`load'  from
/Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/client/rails.rb:27:in
`call'  from
/Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/client/command.rb:7:in
`call'  from
/Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/client.rb:26:in
`run'   from
/Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/bin/spring:48:in `<top
(required)>'  from
/Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/binstub.rb:11:in
`load'  from
/Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/binstub.rb:11:in
`<top (required)>'  from
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in
`require'   from
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in
`require'   from /Users/judobear/toy_app/bin/spring:13:in `<top
(required)>'  from bin/rails:3:in `load'  from bin/rails:3:in `<main>'

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', '4.0.3'
gem 'turbolinks',   '2.3.0'
gem 'jbuilder',     '2.2.3'
gem 'sdoc',         '0.4.0', group: :doc

group :development, :test do
  gem 'sqlite3',     '1.3.9'
  gem 'byebug',      '3.4.0'
  gem 'web-console', '2.0.0.beta3'
  gem 'spring',      '1.1.3'
end

group :production do
  gem 'pg',             '0.17.1'
  gem 'rails_12factor', '0.0.2'
end

Application.rb

require File.expand_path('../boot', __FILE__)

require 'rails/all'

# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)

module Toyapp
  class Application < Rails::Application
    # Settings in config/environments/* take precedence over those specified here.
    # Application configuration should go into files in config/initializers
    # -- all .rb files in that directory are automatically loaded.

    # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
    # config.time_zone = 'Central Time (US & Canada)'

    # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
    # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
    # config.i18n.default_locale = :de

    # Do not swallow errors in after_commit/after_rollback callbacks.
    config.active_record.raise_in_transactional_callbacks = true
  end
end

- cleve yeo

---

你需要一个 Gemfile 文件，并且第一次运行时需要执行 bundle install --without production 命令。 - steve klein

请问您能否发布您的 config/application.rb 文件？ - spickermann

我有一个 gem 文件，然后我运行了 bundle install --without production。 - cleve yeo

请尝试使用bundle exec rails s而不是仅使用rails server，可以吗？ - spickermann

在运行“bundle exec rails s”时出现了相同的错误。 - cleve yeo

你能否更新原始帖子并附上你的 Gemfile 内容？ - steve klein

Answer 1

在我自己遇到同样的问题后，另一个用户发现这是由于Arel gem 6.0.1版本中的错误所致，该错误已经在昨天提出并得以解决:

Rails 4.2.3 `method_missing': undefined method `active_record'

如果你今天运行 "bundle update"，然后继续进行，你的应用程序现在应该正常了。

希望对你有帮助。

- Richard Walker

Answer 2

尝试在您的Gemfile中切换回Rails 4.1.0-不是理想的解决方法，但我今天遇到了完全相同的问题，并且这个方法有效。 我猜这可能是Rails 4.2.x的一个错误（只是猜测）。 编辑：4.1.12也可以使用（是4.1.x中的最新版本）。

- Richard Walker