表D,结构如下:
id varchar2(10),
name varchar2(20),
project varchar2(10),
year number(4,0),
value number(10,2)
需取出不同project的最大value,及其对应年份
id varchar2(10),
name varchar2(20),
project varchar2(10),
year number(4,0),
value number(10,2)
需取出不同project的最大value,及其对应年份
group by project
select distinct
d1.project ,d1.value,d1.year
from d d1,(select project ,max(value) as m_v from d
group by project )d2
where
d1.value=d1.value
and d1.value=d2.m_v