class MigrateCourseAttachments < ActiveRecord::Migration def self.up # 原课程的资源数据迁移成新模式 Attachment.all.each do |attach| if attach.container_type == "Project" project = Project.find_by_id(attach.container_id) if project && project.project_type == 1 attach.container_type= 'Course' attach.container_id = project.course_extra.id attach.save end end end end def self.down end end