Sql 查询中的多个最大值
我知道标题听起来不太具有描述性,但这是我能想到的最好的标题: 我有这张桌子 ID BDATE VALUE 28911 14/4/2009 44820 28911 17/4/2009 32240 28911 20/4/2009 30550 28911 22/4/2009 4422587,5 28911 23/4/2009 4441659 28911 24/4/2009 7749594,67 38537 17/4/2009 58280 38537 20/4/2009 137240 38537 22/4/2009 81098692 38605 14/4/2009 2722368 38605 20/4/2009 5600 38605 22/4/2009 1625400 38605 23/4/2009 6936575 但是它会返回所有的行,因为每个行的值collumn是不同的。此查询是在Oracle v10中设计的,我可以只使用select查询,而不创建过程Sql 查询中的多个最大值,sql,oracle,greatest-n-per-group,Sql,Oracle,Greatest N Per Group,我知道标题听起来不太具有描述性,但这是我能想到的最好的标题: 我有这张桌子 ID BDATE VALUE 28911 14/4/2009 44820 28911 17/4/2009 32240 28911 20/4/2009 30550 28911 22/4/2009 4422587,5 28911 23/4/2009 4441659 28911 24/4/2009 7749594,67 38537 17/4/2009 58280 38537 20
select a.* from myview a, (select id, max(bdate) from myview group by id) b
where a.id = b.id and a.bdate = b.bdate
(未经测试…我现在没有可用的Oracle…您可以使用分析:
select
id, bdate, value
from
(
select
id, bdate, value, max( bdate ) over ( partition by id ) max_bdate
from
myview
)
where
bdate = max_bdate
我们可以在in子句中使用乘法列:
select id, bdate, value
from myview
where (id, bdate) in
(select id, max(bdate)
from myview group by id)
/
可以使用内部联接仅过滤出最大行数:
select t.*
from YourTable t
inner join (
select id, max(bdate) as maxbdate
from YourTable
group by id
) filter
on t.id = filter.id
and t.bdate = filter.maxbdate
这张照片是:
id bdate value
38605 2009-04-23 6936575
38537 2009-04-22 81098692
28911 2009-04-24 7749594.67
请注意,对于具有多个值且具有相同bdate的id,这将返回多行。您可以使用以下构造:
SQL> SELECT ID,
2 MAX(bdate) bdate,
3 MAX(VALUE) KEEP(DENSE_RANK FIRST ORDER BY bdate DESC) VALUE
4 FROM DATA
5 GROUP BY ID;
ID BDATE VALUE
---------- ----------- ----------
28911 24/04/2009 7749594,67
38537 22/04/2009 81098692
38605 23/04/2009 6936575
这将与所建议的分析方法一样有效(无自连接,数据的单次传递)它不会返回值collumn,我想知道您是否会在该查询中添加另一个条件,如“AND value>500”?
select t.*
from YourTable t
inner join (
select id, max(bdate) as maxbdate
from YourTable
group by id
) filter
on t.id = filter.id
and t.bdate = filter.maxbdate
id bdate value
38605 2009-04-23 6936575
38537 2009-04-22 81098692
28911 2009-04-24 7749594.67
SQL> SELECT ID,
2 MAX(bdate) bdate,
3 MAX(VALUE) KEEP(DENSE_RANK FIRST ORDER BY bdate DESC) VALUE
4 FROM DATA
5 GROUP BY ID;
ID BDATE VALUE
---------- ----------- ----------
28911 24/04/2009 7749594,67
38537 22/04/2009 81098692
38605 23/04/2009 6936575