Rails 3.1 pre迁移问题

Question

现在我将rails 3.0.7升级到rails 3.1 pre版本.当我创建一个示例项目时,它工作正常.创建一个脚手架后,我尝试迁移,但它让我的耙子中止了!信息.

在这里我的代码

rails g scaffold product name:string price:decimal category:string
      invoke  active_record
      create    db/migrate/20110517090853_create_products.rb
      create    app/models/product.rb
      invoke    test_unit
      create      test/unit/product_test.rb
      create      test/fixtures/products.yml
       route  resources :products
      invoke  scaffold_controller
      create    app/controllers/products_controller.rb
      invoke    erb
      create      app/views/products
      create      app/views/products/index.html.erb
      create      app/views/products/edit.html.erb
      create      app/views/products/show.html.erb
      create      app/views/products/new.html.erb
      create      app/views/products/_form.html.erb
      invoke    test_unit
      create      test/functional/products_controller_test.rb
      invoke    helper
      create      app/helpers/products_helper.rb
      invoke      test_unit
      create        test/unit/helpers/products_helper_test.rb
      create  app/assets/stylesheets/scaffold.css.scss
      invoke  assets
      create    app/assets/javascripts/products.js.coffee
      create    app/assets/stylesheets/products.css.scss
rake db:migrate
==  CreateProducts: migrating =================================================
-- create_table(:products)
   -> 0.0053s
==  CreateProducts: migrated (0.0054s) ========================================

rake aborted!
An error has occurred, all later migrations canceled:

undefined method `rows' for nil:NilClass

(See full trace by running task with --trace)

我使用的是ruby 1.9.2和xampp.

任何人都可以知道问题是什么吗？

Answer 1

我使用mysql2 v0.2.6作为数据库适配器时遇到了同样的问题.
我试图解决它更新mysql2到最新版本0.3.2,但我无法在Windows上编译此gem.但我仍然认为最新版本的mysql2可能有效.目前我使用"pg"gem作为DB的postgres适配器,它可以与Rails 3.1.pre一起使用