Question

我完全是Ruby的新手，我正在按照Michael Hartl的教程进行操作。在第2章，第49页中，书中指出：

rails generate scaffold User name:string email:string

执行此操作后，应用程序显示：

    C:\demo_app>rails generate scaffold User name:string email:string
C:/demo_app/config/environments/development.rb:1:in `<top (required)>': undefine
d method `configure' for #<DemoApp::Application:0x35d3d98> (NoMethodError)
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-
3.2.3/lib/active_support/dependencies.rb:251:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-
3.2.3/lib/active_support/dependencies.rb:251:in `block in require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-
3.2.3/lib/active_support/dependencies.rb:236:in `load_dependency'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-
3.2.3/lib/active_support/dependencies.rb:251:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/engine.rb:571:in `block in <class:Engine>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/initializable.rb:30:in `instance_exec'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/initializable.rb:30:in `run'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/initializable.rb:55:in `block in run_initializers'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/initializable.rb:54:in `each'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/initializable.rb:54:in `run_initializers'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/application.rb:136:in `initialize!'
        from C:/demo_app/config/environment.rb:5:in `<top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/application.rb:103:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/application.rb:103:in `require_environment!'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/commands.rb:25:in `<top (required)>'
        from bin/rails:4:in `require'
        from bin/rails:4:in `<main>'

我已经使用了捆绑安装，捆绑更新，安装了新版本（和旧版本）的宝石...... 有人可以让我找出错误吗？或者一种避免这种错误的方法，以便遵循下一步。

谢谢，

Answer 1

试试这个：

bundle exec rails generate scaffold User name:string email:string

Answer 2

我解决了这个问题。步骤是：

更正第一行development.rb

DemoApp::Application.configure do

后来当我尝试执行rails generate scaffold User name:string email:string时，我发现了另一个问题。问题的描述是： C：\ demo_app＆gt; rails generate scaffold用户名：string email：string 调用active_record C：/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activerecord-3.2.3/lib/acti ve_record / dynamic_matchers.rb:50:in method_missing': undefined method migratio N_ERROR =＆＃39; for ActiveRecord :: Base：Class（NoMethodError）
最后，我删除config/environments/development.rb中的以下行： config.active_record.migration_error = :page_load

我在下一个答案中使用了一个混合：

执行rails生成脚手架时出错用户名：string email：string

2 个答案: