SQL Server数据转换

Question

我有格式的数据：

Date, FirstName, LastName, Unit
Jan1 , Bob      , Guy     , Home
Jan2 , Bob      , Guy     , Home
Jan3 , Bob      , Guy     , Home
Jan5 , Bob      , Guy     , Home
Jan6 , Bob      , Guy     , Home
Jan7 , Bob      , Guy     , Home
Jan8 , Bob      , Guy     , Offsite
Jan3 , Jane     , Doe     , Home
Jan4 , Jane     , Doe     , Home
Jan5 , Jane     , Doe     , Home
Jan9 , Bob      , Guy     , Home
Jan10, Bob      , Guy     , Home
Jan11, Bob      , Guy     , Home
Jan12, Jane     , Doe     , Home
Jan13, Jane     , Doe     , Home
Jan14, Jane     , Doe     , Home

我想要它的格式

DateStart, DateEnd, FirstName, LastName, Unit
Jan1     , Jan3   , Bob      , Guy     , Home
Jan5     , Jan7   , Bob      , Guy     , Home
Jan8     , Jan8   , Bob      , Guy     , Offsite
Jan3     , Jan5   , Jane     , Doe     , Home
Jan9     , Jan11  , Bob      , Guy     , Home
Jan12    , Jan14  , Jane     , Doe     , Home

编辑：更新数据。

如何轻松转换数据？

这是一次转换。

感谢您的评论/答案！

Answer 1

下面的SQL会产生所需的输出，但是我不确定您是否不太好编写这是C＃

更新这已更新为适当的差距和岛屿解决方案。这是基于MSDN文章 顺序数字的岛屿和差距 亚历山大·科扎克（Alexander Kozak）。可以通过使用CTE来改善这一点，并且可以用左连接来代替存在。

应该注意的是，这取决于日期没有任何时间组件。如果有时间组件，则必须在前面删除。

输出

Date                    enddate                 FirstName LastName Unit
----------------------- ----------------------- --------- -------- -------
2011-01-01 00:00:00.000 2011-01-03 00:00:00.000 Bob       Guy      Home
2011-01-03 00:00:00.000 2011-01-05 00:00:00.000 Jane      Doe      Home
2011-01-05 00:00:00.000 2011-01-07 00:00:00.000 Bob       Guy      Home
2011-01-08 00:00:00.000 2011-01-08 00:00:00.000 Bob       Guy      Offsite
2011-01-09 00:00:00.000 2011-01-11 00:00:00.000 Bob       Guy      Home
2011-01-12 00:00:00.000 2011-01-14 00:00:00.000 Jane      Doe      Home

SQL语句

SET NOCOUNT On

DECLARE @Test 
Table (
    Date datetime, 
    FirstName varchar(100),
     LastName varchar(100), 
     Unit  varchar(7))



INSERT INTO @Test VALUES ('01/01/2011'  , 'Bob', 'Guy',  'Home')
INSERT INTO @Test VALUES ('01/02/2011'  , 'Bob', 'Guy',  'Home')
INSERT INTO @Test VALUES ('01/03/2011'  , 'Bob', 'Guy',  'Home')
INSERT INTO @Test VALUES ('01/05/2011'  , 'Bob', 'Guy',  'Home')
INSERT INTO @Test VALUES ('01/06/2011'  , 'Bob', 'Guy',  'Home')
INSERT INTO @Test VALUES ('01/07/2011'  , 'Bob', 'Guy',  'Home')
INSERT INTO @Test VALUES ('01/08/2011'  , 'Bob', 'Guy',  'Offsite')
INSERT INTO @Test VALUES ('01/03/2011'  , 'Jane', 'Doe',  'Home')
INSERT INTO @Test VALUES ('01/04/2011'  , 'Jane', 'Doe',  'Home')
INSERT INTO @Test VALUES ('01/05/2011'  , 'Jane', 'Doe',  'Home')
INSERT INTO @Test VALUES ('01/09/2011'  , 'Bob', 'Guy',  'Home')
INSERT INTO @Test VALUES ('01/10/2011'  , 'Bob', 'Guy',  'Home')
INSERT INTO @Test VALUES ('01/11/2011'  , 'Bob', 'Guy',  'Home')
INSERT INTO @Test VALUES ('01/12/2011'  , 'Jane', 'Doe',  'Home')
INSERT INTO @Test VALUES ('01/13/2011'  , 'Jane', 'Doe',  'Home')
INSERT INTO @Test VALUES ('01/14/2011'  , 'Jane', 'Doe',  'Home')


SELECT 
    t1.Date,
    MIN(t2.Date) enddate, 
    t1.FirstName,
    t1.LastName,
    t1.Unit
 FROM

    (SELECT * 
    FROM
        @Test t1
    WHERE
       NOT EXISTS(SELECT * FROM @Test t2
                  WHERE
                      t1.firstName = t2.FirstName   
                      AND t1.LastName = t2.LastName
                      AND t1.Unit = t2.Unit
                        and t1.Date - t2.Date = 1)) 
        t1


      INNER JOIN (SELECT * FROM @Test t1

    WHERE
       NOT EXISTS(SELECT * FROM @Test t2
                  WHERE
                      t1.firstName = t2.FirstName   
                      AND t1.LastName = t2.LastName
                      AND t1.Unit = t2.Unit
                        and t2.Date - t1.Date = 1)) t2
      ON
        t1.firstName = t2.FirstName 
                      AND t1.LastName = t2.LastName
                      AND t1.Unit = t2.Unit
                      AND t1.Date <= t2.Date  
       GROUP BY
       t1.Date,
       t1.FirstName,
       t1.LastName,
       t1.Unit

Answer 2

使用Conrad的测试数据和Itzik Ben Gan的方法！

;WITH base AS ( 
SELECT    FirstName, 
          LastName, 
          Unit,
          Date,
          DATEDIFF(DAY,0,Date) - 
                         DENSE_RANK() OVER (PARTITION BY FirstName, LastName, Unit 
                                            ORDER BY DATEDIFF(DAY,0,Date)) AS G
 FROM     @Test
 )
SELECT FirstName, LastName, Unit, MIN(Date) DateStart,MAX(Date) DateEnd
FROM base
GROUP BY G, FirstName, LastName, Unit