sql 開窗函數

 按名字分組，按時間排序

 

 

select * FROM (
select row_number() over (partition by NAME order by DAT desc) rn ，name，dat

FROM QWER

) tn where tn.rn=1;

或

SELECT a.* from QWER a,
(SELECT name,max(dat) dat FROM QWER GROUP BY name) b where
a.tim=b.dat
and
b.name=a.name;