Question

我有一个数据表，其中单个连续记录可能有多个条目。

Empno           StartDate            EndDate         Wdays
1               2014-07-23           2014-07-23        1
1               2014-11-07           2014-11-29        15
1               2014-11-30           2014-12-07        8
1               2014-12-08           2014-12-19        11
2               2014-11-15           2014-11-16        2

如果开始日期在同一个empno的结束日期之后，我希望只显示一条记录，如下所示。

Empno           StartDate            EndDate          Wdays
1               2014-07-23           2014-07-23         1
1               2014-07-23           2014-12-19         34       
2               2014-11-15           2014-11-16         2

我已经用下面显示的答案解决了日期问题，但是任何人都可以帮我总结每个实例的“Wdays”

Answer 1

select empno, 
       min(startdate) as startdate,
       max(enddate) as enddate
from your_table
group by empno

Answer 2

感谢那些发布到我原始查询的人，如果我不清楚我遇到的问题，我会道歉。以下是问题如何解决我通过使用答案＆＃34; ypercube＆＃34; （https://stackoverflow.com/users/344949/ypercube）发布于2012年

With StartData As
( Select
  , empno
  , startdate
  , enddate
  , desc
  , wdays

  From 
   Mytable  

)
,
StartD AS
  ( SELECT 
    Empno
  , startdate
  , ROW_NUMBER() OVER( PARTITION BY Empno ORDER BY startdate )
      AS Rn 
FROM
    StartData AS t
WHERE
    NOT EXISTS
    ( SELECT *
      FROM StartData AS p
      WHERE p.empno = t.empno
        AND p.startdate < t.startdate 
        AND t.startdate <= DATEADD(day, 1, p.EndDate)
    )
 )
, EndD AS
( SELECT 
    empno
  , EndDate
  , ROW_NUMBER() OVER( PARTITION BY empno ORDER BY EndDate )
      AS Rn 
FROM
    StartData AS t
WHERE
    NOT EXISTS
    ( SELECT *
      FROM StartData AS p
      WHERE p.empno = t.empno
        AND DATEADD(day, -1, p.startdate) <= t.EndDate
        AND t.EndDate < p.EndDate
    )
 )
 SELECT
 s.empno
 , s.startdate
 , e.EndDate
 FROM
StartD AS s
JOIN
EndD AS e
  ON  e.empno = s.empno
  AND e.Rn = s.Rn

SQL如何合并记录，其中开始日期遵循结束日期

2 个答案: