根据由另一列分组的不同列的最大值获取值

I want to get the values of a column based on max of a different column grouped by another column.

我有这张桌子:

KEY NUM VAL
A   1   AB
B   1   CD
B   2   EF
C   2   GH
C   3   HI
D   1   JK
D   3   LM

想要这个结果:

KEY VAL
A   AB
B   EF
C   HI
D   LM

我实际上可以使用这个查询来获取它.

select KEY, VAL
from TABLE_NAME TN
where NUM = (
    select max(NUM)
    from TABLE_NAME TMP
    where TMP.KEY = TN.KEY
    )

select key, val
from (select t.*, row_number() over (partition by key order by num desc) as seqnum
      from table_name t
     ) t
where seqnum = 1;