mysql删除多字段重复的数据
create table tmp as select min(id) as col1 from blur_article group by title;
delete from blur_article where id not in (select col1 from tmp);
drop table tmp;


create table tmp as select min(id) as col1 from followers group by user_id,follower_id;

delete from followers where id not in (select col1 from tmp);