【发布时间】：2015-08-04 16:59:19
【问题描述】：
我还在学习 Ruby（所以我完全是菜鸟），
现在我的应用程序在本地成功运行，但是当我尝试在 heroku 上打开应用程序时，我第一次执行 heroku run rake db:migrate 我偶然发现了一个问题.. 它告诉我：
Running `rake db:migrate` attached to terminal... up, run.2149
-- attr_accessible(:pName, :pQuantity, :pMeter, :pWeight, :pSellPrice, :pCategory, :pPic)
-- attr_accessible(:pName, :pQuantity, :pMeter, :pWeight, :pSellPrice, :pCategory, :pPic)
rake aborted!
NoMethodError: undefined method `attr_accessible' for #<ActiveRecord::Migration:0x007f2dc2ba45b8>
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:648:in `block in method_missing'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:621:in `block in say_with_time'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:621:in `say_with_time'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:641:in `method_missing'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:406:in `method_missing'
/app/db/migrate/20150802134246_create_inventories.rb:2:in `<class:CreateInventories>'
/app/db/migrate/20150802134246_create_inventories.rb:1:in `<top (required)>'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:247:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:247:in `block in require'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:232:in `load_dependency'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:247:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:761:in `load_migration'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:757:in `migration'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:752:in `disable_ddl_transaction'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:1044:in `use_transaction?'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:954:in `rescue in block in migrate'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:951:in `block in migrate'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:948:in `each'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:948:in `migrate'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:807:in `up'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:785:in `migrate'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/railties/databases.rake:34:in `block (2 levels) in <top (required)>'
Tasks: TOP => db:migrate
我一直在试图找出原因，在想了想之后我发现 rails 4.0.0 的变化不再使用 attr_accessible 我们应该使用 strong 参数，所以从模型中删除 attr_accessible 将解决问题...
但是，我有一个空模型，我看的任何地方都没有 attr_accessible。 （除此之外，为什么我的应用程序在本地运行而不是在 heroku 上运行很奇怪？） 我无法弄清楚为什么会出现此错误以及在哪里寻找解决方案。我一直在尝试查看 active_record 文件，但害怕做出任何更改，有什么想法吗？
另外，谁能告诉我任何可以帮助我阅读此类日志错误的资源？我试图阅读一些文章，但找不到像我这样的菜鸟容易理解的文章...... ;(
【问题讨论】：
-
您似乎在迁移文件中使用了
attr_accessible。打开/app/db/migrate/20150802134246_create_inventories.rb，看看里面有什么。 -
您可能不小心添加/修改了“旧”迁移文件。您从未在本地看到影响，因为 db:migrate 只会在本地运行“新”迁移，但如果没有在 heroku 上运行迁移，则会遇到错误
-
@XMLSlayer 哇！谢啦！有用！之前没注意！！你一天更安全！
-
@mtamhankar 感谢您的解释！
标签： ruby-on-rails ruby ruby-on-rails-3 heroku attr-accessible