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