T-SQL百万记录中分组取最大值方法ROW_NUMBER() OVER（）

SELECT SysUserID, UserID, 
ROW_NUMBER() OVER(PARTITION BY UserID ORDER BY AddTime DESC) AS nums
FROM dbo.AssignHistoryLog WHERE AssignType = 2
AND SysUserID IN (SELECT userid FROM jdrcadmin.admin WHERE 
deptId IN (17,18,57,80,33) AND isValid=1)

查询结果如下图：