trustieforge/db/migrate/20140722024513_update_course_attachment.rb

class UpdateCourseAttachment < ActiveRecord::Migration
  # 更新课程资源类型
  def up
    Attachment.all.each do |attachment|
      if attachment.container_type == 'Course'
        if attachment.attachtype == 1
          attachment.attachtype = 4
        elsif attachment.attachtype == 2
          attachment.attachtype = 5
        elsif attachment.attachtype == 3
          attachment.attachtype = 6
        end
        attachment.save
      end
    end
  end

  def down
  end
end