1

我有这个示例表：

ColA   ColB   ColC
CBCP    25    popx
ABC1    10    ppp1
ABC1    25    ppxx
CBCP    30    xm2x

从那里我想得到这些列

ColA   ColB   ColC
ABC1    25    ppxx
CBCP    30    xm2x

我想要的是获得最大 ColB 的行。但是当我尝试在查询中包含 ColC 时出现错误：

select ColA, max(ColB), ColC
from tblCaseDev
where ColB > getdate() group by ColA

这是我的错误..

Msg 8120, Level 16, State 1, Line 1
Column 'tblCaseDev.ColC' is invalid in the
select list because it is not contained in either
an aggregate function or the GROUP BY clause.

希望有人可以帮助我..提前谢谢..

4

4 回答 4

2 
SELECT
CaseNo,Date,Remarks,

(SELECT max(cast(Date as datetime)) FROM tblCaseDev subc WHERE subc.CaseNo=c.CaseNo Group by c.CaseNo) AS MaxEntryDate

FROM tblCaseDev c 

order by CaseNo
于 2013-08-28T03:05:08.593 回答
1

您想使用row_number()窗口功能：

select CaseNo, "Date", Remarks
from (select t.*, row_number() over (partition by caseno order by date desc) as seqnum
      from tblCaseDev t
      where date > getdate()
     ) t
where seqnum = 1;

编辑：

如果你没有，你可以用老式的方式做到这一点row_number()：

select t.*
from tblCaseDev t join
     (select caseno, max(date) as maxdate
      from tblCaseDev 
      group by caseno
     ) tsum
     on t.caseno = tsum.caseno and t.date = tsum.maxdate
于 2013-08-28T01:35:19.180 回答
1

您可以先创建聚合查询，然后将原始表连接到聚合查询。

例子：

SELECT
    A.CaseNo,
    A.Date,
    B.Remarks
FROM (
    SELECT
        CaseNo,
        MAX(Date)
    FROM tblCaseDev 
    WHERE Date > GetDate()
    GROUP BY CaseNo
) A 
JOIN tblCaseDev B
    ON A.CaseNo = B.CaseNo
    AND A.Date = B.Date
于 2013-08-28T01:38:57.833 回答
0

您可以使用ROW_NUMBER()which 为每个组生成序列号ColA并按降序排列ColB。

SELECT     ColA, ColB, ColC
FROM 
          (
               SELECT    ColA, ColB, ColC,
                         ROW_NUMBER() OVER(PARTITION BY ColA 
                                           ORDER BY ColB DESC) rn
               FROM tablename
          ) x
WHERE     rn = 1

如果您想获得多个关联的记录ColB，您可能需要将其更改为DENSE_RANK().

于 2013-08-28T01:34:12.710 回答