Question

我在连接上获得重复记录，我只想在NSANOTES.NOTEDATE上使用MAX（最新）日期。你好吗？

SELECT NSAACTIVITY.NSAID ,
NSAACTIVITY.NSASERVICEIMPACTED "Type",  
NSAACTIVITY.NSAAPPROVED,
NSAACTIVITY.NSADESCRIPTION,
NSANOTES.NSANOTE 
FROM NSAUSER.NSAACTIVITY INNER JOIN NSAUSER.NSANOTES ON NSAACTIVITY.NSAID=NSANOTES.NSAID
WHERE TO_CHAR(NSAACTIVITY.NSASTART, 'yyyy-mm-dd hh24:mi') BETWEEN '2013-06-28 10:59:59' AND '2013-07-01 06:00:01'

Answer 1

我认为你正在寻找下面的内容。我把关于在WHERE子句中使用timestamp而不是to_char的线索。休息仅仅是使用RANK（）函数。希望这有帮助

SELECT *
  FROM (SELECT act.NSAID,
               act.NSASERVICEIMPACTED "Type",
               act.NSAAPPROVED,
               act.NSADESCRIPTION,
               notes.NSANOTE,
               rank()
                  OVER (PARTITION BY act.NSAID ORDER BY notes.NOTEDATE DESC) rn
          FROM    NSAUSER.NSAACTIVITY act
               INNER JOIN
                  NSAUSER.NSANOTES notes
               ON act.NSAID = notes.NSAID
         WHERE act.NSASTART BETWEEN TIMESTAMP '2013-06-28 10:59:59' AND TIMESTAMP '2013-07-01 06:00:01'
                                                            )
                                                            where rn=1;

Answer 2

您是否尝试过使用群组？类似的东西：

SELECT NSAACTIVITY.NSAID ,
NSAACTIVITY.NSASERVICEIMPACTED "Type",  
NSAACTIVITY.NSAAPPROVED,
NSAACTIVITY.NSADESCRIPTION,
NSANOTES.NSANOTE,
MAX(NSANOTES.NOTEDATE)
FROM NSAUSER.NSAACTIVITY INNER JOIN NSAUSER.NSANOTES ON NSAACTIVITY.NSAID=NSANOTES.NSAID
WHERE TO_CHAR(NSAACTIVITY.NSASTART, 'yyyy-mm-dd hh24:mi') BETWEEN '2013-06-28 10:59:59' AND '2013-07-01 06:00:01'
GROUP BY NSAACTIVITY.NSAID ,
NSAACTIVITY.NSASERVICEIMPACTED,  
NSAACTIVITY.NSAAPPROVED,
NSAACTIVITY.NSADESCRIPTION,
NSANOTES.NSANOTE

Answer 3

我认为这样的事情可以解决问题（使用子查询）

SELECT NSAACTIVITY.NSAID ,
NSAACTIVITY.NSASERVICEIMPACTED "Type",  
NSAACTIVITY.NSAAPPROVED,
NSAACTIVITY.NSADESCRIPTION,
ns.NSANOTE 
FROM NSAUSER.NSAACTIVITY INNER JOIN NSAUSER.NSANOTES ns ON NSAACTIVITY.NSAID=ns.NSAID
WHERE TO_CHAR(NSAACTIVITY.NSASTART, 'yyyy-mm-dd hh24:mi') BETWEEN '2013-06-28  10:59:59' AND '2013-07-01 06:00:01'
and ns.NOTESDATE= (SELECT MAX(ns2.NOTESDATE) FROM NSAUSER.NSANOTES ns2 where ns2.NSAID = ns.NSAID)

我怎么说连接表上的MAX日期

3 个答案: