select max(V4MAXSPEED) over(partition by atid), ID from t_anerecord
select ID,V4MAXSPEED from ( select row_number()over(partition by atid order by V4MAXSPEED desc) rn, ID, V4MAXSPEED from t_anerecord ) where rn=1
select max(V4MAXSPEED) over(partition by atid order by V4MAXSPEED desc), ID from t_anerecord group by atid 为什么不是 group by 语句呢 如何在分组的基础上 找出最大值和 该最大值这行的信息呢
partition by也是分组 这个相当于group by 2L的结果应该是对的 可以参考下 分组倒序排列取第一个 就是每组的最大值
“分组中取最大的值(max) 并取这个最大的值的ID 一起显示出来”理解起来是要找t_anerecord 中最大值的那行记录啊, select V4MAXSPEED, id from (select V4MAXSPEED, ID from t_anerecord order by V4MAXSPEED desc) where rownum = 1
select row_number()over(partition by atid order by V4MAXSPEED desc) rn,
ID,
V4MAXSPEED
from t_anerecord )
where rn=1
为什么不是 group by 语句呢 如何在分组的基础上 找出最大值和 该最大值这行的信息呢
partition by也是分组 这个相当于group by 2L的结果应该是对的 可以参考下 分组倒序排列取第一个 就是每组的最大值
select V4MAXSPEED, id
from (select V4MAXSPEED, ID from t_anerecord order by V4MAXSPEED desc)
where rownum = 1