mysql 去除表中重复的数据，保留id最小的数据信息

-- 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 )