gistfile1.rb

$ rake db:structure:dump
$ echo "create database myapp_test2;" | mysql -uroot
$ mysql -uroot -Dmyapp_test2 < db/development_structure.sql
$ vim config/database.yml # add some ERB to config/database.yml

  test:
    adapter: mysql
    encoding: utf8
    database: myapp_test<%= ENV['TEST_ENV_NUMBER'] %>
    username: root