?
1.取得不重复的数据
select * from Persons where Id in
(
SELECT ? ?MAX(Id) AS Expr1
FROM ? ?Persons
GROUP BY Name, Gender
)
?
2.删除重复的数据【MAX换成MIN会有不同的效果】
?
delete from Persons
where Id not in
(
SELECT ? ?MAX(Id) AS Expr1
FROM ? ?Persons
GROUP BY Name, Gender
)
?