-- 笨重方法
delete from
tb_person
WHERE
id NOT IN ( select id from (SELECT min(id) id FROM tb_person GROUP BY email having count(1) > 1) tm)
and email in ( select email from ( SELECT email FROM tb_person GROUP BY email having count(1) > 1)tm)
-- 获取最小id,排除id信息进行删除
DELETE from Person Where Id not in ( Select MIN(Id) as Id From Person Group by Email )