mysql 去重, 折腾了好一会(临时表很重要, 不然会出错)

 delete from t_video_addr where id in( select t.id from (select t1.id from t_video_addr t1, t_video_addr t2 where t1.id>t2.id  and t1.play_url=t2.play_url and t1.vid=t2.vid and t1.eid=t2.eid) t );