data migration from "lib/migration/*.rb"

db_migrate_x.rb

namespace :db do
  namespace :migrate do
    Dir::glob("lib/migration/*.rb").each do |file|
      target = File.basename(file, ".rb")
      desc "migration task from \"lib/migration/#{target}.rb\""
      task target => :environment do
        require file
        klass = target.split("_").map {|word| word.capitalize}.join("")
        data_source = YAML.load_file(Rails.root.join('config', 'old_migration_database.yml'))
        data_source.each do |system, ds|
          klass = target.split("_").map {|word| word.capitalize}.join("")
          display_message("System:#{system} #{klass} Begin -- #{DateTime.now.strftime("%Y-%m-%d %H:%M:%S.%N")}")
          data_obj = eval("#{klass}.new(system, ds)")
          data_obj.migration
          display_message("System:#{system} #{klass} End -- #{DateTime.now.strftime("%Y-%m-%d %H:%M:%S.%N")}")
        end
      end
    end
    desc "migration all data from old_migration_database"
    task :all => :environment do
      Dir::glob("lib/migration/*.rb").each do |file|
        target = File.basename(file, ".rb")
        Rake::Task["db:migrate:#{target}"].invoke
      end
    end
    namespace :all do
      desc "migration all data from old_migration_database"
        task :reset => :environment do
          Rake::Task["db:migrate:reset"].invoke
          require 'db/seeds'
          Rake::Task["db:migrate:all"].invoke
        end
      end
  end
end

データ移行用rake task
新旧データベースのデータ移行に利用する
old_migration_database.ymlに適当なデータソース定義を、lib/migration/以下にデータ移行クラスファイルを配置