Question

我需要创建查询以从相同记录中选择MAX日期列记录。我正在使用此查询，但它返回相同的记录

SELECT DISTINCT SID, Id, MAX(ExpireDate) FROM tblPayers GROUP BY id,SID,ExpireDateEn

但我得到的结果是：

SID    Id    ExpireDate
2      3     5/25/2017
3      12    6/27/2017
1      13    5/28/2017
1      14    6/27/2017

Answer 1

只需从分组中删除ExpireDate，也可以从查询中删除，因为这也不是必需的： -

Select distinct SID, id, ExpireDate
from tblPayers a
inner join
(
    select SID,MAX(ExpireDate) as dt 
    from tblPayers 
    group by SID
) b
on a.SID=b.SID and a.ExpireDate=b.dt

Answer 2

基于对另一个答案的评论（“它返回2个相同的SID，我只需要返回一个最大SID记录”）我猜你只想要每个SID的最新记录，返回所有其他专栏。

为此，您可以使用ROW_NUMBER()：

SELECT  p.ID, 
        p.[SID], 
        p.[ExpireDate]
FROM    (   SELECT  p.ID, 
                    p.[SID], 
                    p.[ExpireDate],
                    RowNum = ROW_NUMBER() OVER(PARTITION BY p.[SID] 
                                                ORDER BY p.[ExpireDate] DESC)
            FROM    dbo.tblPayers AS p
        ) AS p
WHERE   p.RowNum = 1;

Answer 3

with tablecte(sid,expiredate)
as
(
select SID , Max(ExpireDate)
    from tblPlayers 
    group by  SID
)
select tp.SID,tp.Id,tp.ExpireDate from tblPlayers tp join  tablecte tc
on tp.SID = tc.sid and tp.Expiredate = tc.expiredate

在SQL Server

3 个答案: