菜鸟求教：报错 “ActiveRecord::ConnectionNotEstablished”

ghyghoo8 — Wed, 25 Jan 2012 11:43:14 +0800

Started GET "/say/hello" for 127.0.0.1 at 2012-01-25 11:33:35 +0800

ActiveRecord::ConnectionNotEstablished (ActiveRecord::ConnectionNotEstablished):


Rendered C:/Ruby192/lib/ruby/gems/1.9.1/gems/actionpack-3.1.0/lib/action_dispatch/middleware/templates/rescues/_trace.erb (1.0ms)
Rendered C:/Ruby192/lib/ruby/gems/1.9.1/gems/actionpack-3.1.0/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (1.0ms)
Rendered C:/Ruby192/lib/ruby/gems/1.9.1/gems/actionpack-3.1.0/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (6.0ms)

网上查了很多答案，都是说数据库未连接什么的，但是，我检查了配置：

development:
  adapter: mysql
  encoding: utf8
  reconnect: false
  database: hw2_development
  pool: 5
  username: root
  password:123
  host: localhost

貌似没什么错误啊，连接正常 sqlite3 也装了。。。。话说，首页http://127.0.0.1:3000请求个图片都请求不了：

Started GET "/assets/rails.png" for 127.0.0.1 at 2012-01-25 11:05:12 +0800
ActiveRecord::ConnectionNotEstablished (ActiveRecord::ConnectionNotEstablished):
......

求高手帮忙解答呀…… 诚心学习 ing