Rails自带了development、test和production三个environments，而我们可以轻松添加自己的environment：
1，修改database.yml

staging:
  adapter: mysql
  database: store_staging
  user: root
  password: 
  host: localhost

2，添加enviromnets/staging.rb

# ...
config.log_level = :debug
# ...

3，创建数据库

mysqladmin create store_staging -u root -p
rake db:migrate RAILS_EVN=staging

4，以staging环境启动Server

script/server -e staging