SELECT a.kefu_id,b.kefu_id FROM roncoo_education_course.`order_info` a JOIN roncoo_education_user.`user_ext` b ON a.`user_no`=b.`user_no`;
UPDATE order_info as aa INNER JOIN
(SELECT a.id,b.kefu_id FROM roncoo_education_course.`order_info` a JOIN roncoo_education_user.`user_ext` b ON a.`user_no`=b.`user_no`)bb on aa.id = bb.id set aa.kefu_id = bb.kefu_id