## plik modelu:

class OldDb < ActiveRecord::Base
  self.abstract_class = true
  establish_connection(
    :adapter  => 'mysql',
    :host     => 'dsfdsa',
    :username => 'dsfdsaf',
    :password => 'sdafdasfd',
    :database => 'sdfds')
end


## w pliku migracji

 class ImportBlah < ActiveRecord::Migration
  def self.up
    old = OldDb.connection.execute("SET names latin1")
    old = OldDb.connection.execute("SELECT * FROM blah")
    while o = old.fetch_hash
      for k,v in o
        o[k] = Iconv.conv('utf-8','iso-8859-2',v)
      end
    # blah blah blah