删除重复数据的方法
1
delete
2FROM TestTable
3WHERE (Userid NOT IN
4 (SELECT Userid
5 FROM (
6 SELECT MAX(Userid) AS Userid FROM TestTable
7 GROUP BY Userid) a))
8
delete 2
FROM TestTable3
WHERE (Userid NOT IN4
(SELECT Userid5
FROM (6
SELECT MAX(Userid) AS Userid FROM TestTable7
GROUP BY Userid) a))8
