mysql 去除重复项

表名：stu_info
字段有：id,name
创建一个临时表 tmp ，把表中的id作为字段并且以去重复的那项进行分组，把具有重复项的复制到一张表中


create table tmp as select min(id) as col1 from stu_info group by(name) ;
delete from stu_info  where id not in (select col1 from tmp);
drop table tmp;