sql 删除重复记录，只保留ID号最大的记录

--查找sfzh重复的数据
SELECT * from Sheet1 where sfzh in
(SELECT sfzh from Sheet1 GROUP BY sfzh HAVING count(*)>1)

--删除重复记录，只保留ID号最大的一条
delete from Sheet1
where sfzh in (select sfzh from Sheet1 group by sfzh having count(sfzh) > 1)
and id not in (select max(id) from Sheet1 group by sfzh having count(sfzh)>1)

--查看全部记录
SELECT * from Sheet1