sql-选择为一个字段记录相同的值,在另一个字段上记录不同的值
我有一个疑问:sql-选择为一个字段记录相同的值,在另一个字段上记录不同的值,sql,select,db2,Sql,Select,Db2,我有一个疑问: select CPRCOSC, CPRCDCO, FCHPRDT ,CPRDTPA from ocsacpr, fasaorl, fasaorh where CPRCOSC = 'GHY02' and fclcosc = CPRCOSC and fclcdcm = CPRCDCO and fclverc = CPRVER and fclnumc = CPRNUM and FCHORDN = FCLORDN and FCHCOSC = F
select CPRCOSC, CPRCDCO, FCHPRDT ,CPRDTPA
from ocsacpr,
fasaorl,
fasaorh
where CPRCOSC = 'GHY02'
and fclcosc = CPRCOSC
and fclcdcm = CPRCDCO
and fclverc = CPRVER
and fclnumc = CPRNUM
and FCHORDN = FCLORDN
and FCHCOSC = FCLCOSC
它给了我:
CPRCOSC CPRCDCO FCHPRDT CPRDTPA
GHY02 2015000036 20150728 20150728
GHY02 2015000037 20150723 20150723
GHY02 2015000038 20150722 20150722
GHY02 2015000039 20150918 20150930
GHY02 2015000040 20150918 20150930
.....
GHY02 2015000041 20150731 20150731
GHY02 2015000041 20150918 20150831
GHY02 2015000041 20150921 20150930
对于最后3条记录(具有相同的cprcco
),我只想选择FCHPRDT
更高的记录(20150921
)
如何编辑查询
提前感谢您可以使用窗口函数(第一个值),通过CPRCDO进行分区,并通过FCHPRDT(降序)进行排序。看看函数文档 下面的代码将很好地工作,但我建议您也使用内部连接子句,而不是在WHERE子句中进行连接
SELECT DISTINCT
CPRCOSC,
CPRCDCO,
FIRST_VALUE(FCHPRDT) OVER (PARTITION BY CPRCDCO ORDER BY FCHPRDT DESC) AS FCHPRDT,
FIRST_VALUE(CPRDTPA) OVER (PARTITION BY CPRCDCO ORDER BY FCHPRDT DESC) AS CPRDTPA
FROM
OCSACPR, FASAORL, FASAORH
WHERE
CPRCOSC = 'GHY02'
AND FCLCOSC = CPRCOSC
AND FCLCDCM = CPRCDCO
AND FCLVERC = CPRVER
AND FCLNUMC = CPRNUM
AND FCHORDN = FCLORDN
AND FCHCOSC = FCLCOSC
使用公共表表达式(保存一些键入)。如果没有其他行具有相同的
cprcdo
且具有更高的FCHPRDT
,则使用notexists
返回一行:
with cte as
(
select CPRCOSC, CPRCDCO, FCHPRDT ,CPRDTPA
from ocsacpr,
fasaorl,
fasaorh
where CPRCOSC = 'GHY02'
and fclcosc = CPRCOSC
and fclcdcm = CPRCDCO
and fclverc = CPRVER
and fclnumc = CPRNUM
and FCHORDN = FCLORDN
and FCHCOSC = FCLCOSC
)
select * from cte t1
where not exists (select 1 from cte t2
where t2.CPRCDCO = t1.CPRCDCO
and t2.FCHPRDT > t1.FCHPRDT)
首先可以使用表别名限定所有列名,并使用显式的
join
语法。虽然这不能解决你的问题,但它会让其他人知道你在做什么。示例数据和SQL FIDLE也很有用,您实际使用的数据库标记也是如此。它非常适合IBM db2 db!谢谢