gistfile1.rb

import 'Items' do
  from 'items' do |sequel|
    sequel[<<-SQL
SELECT tblItems.point as hello
FROM tblItems
INNER JOIN tblOrderItems ON tblOrderItems.sItemID =  tblItems.sID
SQL
          ]
  end
  to 'items'

  mapping 'hello' => mapping 'new_hello'
end