正如其他人在评论中指出的那样,我认为,我们回顾的设计/结构是巨大的。 如果你能够保证各行各行各行各行各行各行各行,即每两行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行,第二行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行各行。

;WITH OrderedTable AS
(
    SELECT  Unit
            , IDNumber
            , EnteredDateTime
            , ROW_Number() OVER (Partition BY Unit ORDER BY Unit) RN 
    FROM    @t -- YOUR TABLE NAME GOES HERE
)
SELECT  t1.Unit
        , t1.IDNumber
        , t1.EnteredDateTime as TimeIn
        , t2.EnteredDateTime as TimeOut
        , DATEDIFF(hour, t1.EnteredDateTime, t2.EnteredDateTime ) TimeElapsedInHours
FROM    OrderedTable t1
JOIN    OrderedTable t2 ON t1.Unit = t2.Unit AND t2.RN = t1.RN + 1
WHERE   t1.RN % 2 <> 0

但我想说清楚——我不知道这一解决办法是建立在你的实际数据基础上的。 然而,它将根据你提供的抽样数据,给你希望的结果。

即便由于你的数据模式,你也能够使用这一准确的方法,但我感到,你可能利用其中的一些东西来制定解决办法。 如果没有任何东西,这些内容将引人注意。

• DATEDIFF function
• Common Table Expressions
• ROW_NUMBER function

这里使用的测试是......

declare @t TABLE
(
    LogId   int,
    SiteNumber  int,
    Unit        varchar(50),
    IDNumber    int ,
    LogCode   varchar(50),
    EnteredDateTime  datetime,          
    ChangeMode    varchar(50),       
    HowEntered varchar(50)
)

insert into @t values (851, 1,  16 - 0 , 23502,  BDISCHSET ,  2011-11-12 11:48:08.890 ,  Discharging Soon ,  SERIES )
insert into @t values (866, 1,  16 - 0  , NULL,  BDISCHRED ,  2011-11-12 21:45:11.657 ,  Discharged ,  SERIES )
insert into @t values (113, 2,  2001 - 0 , 12384,  BDISCHSET ,  2011-10-28 09:27:08.773 ,  Discharging Soon ,  SERIES )
insert into @t values (125, 2,  2001 - 0 , NULL,  BDISCHRED ,  2011-10-28 10:38:08.060 ,  Discharged ,  SERIES )
insert into @t values (119, 2,  2002 - 0 , 12394,  BDISCHSET ,  2011-10-28 10:01:12.443 ,  Discharging Soon ,  SERIES )
insert into @t values (139, 2,  2002 - 0 , NULL,  BDISCHRED ,  2011-10-28 14:01:11.120 ,  Discharged ,  SERIES )
insert into @t values (776, 2,  2002 - 0 , 12331,  BDISCHSET ,  2011-11-10 09:08:09.443 ,  Discharging Soon ,  SERIES )
insert into @t values (783, 2,  2002 - 0 , NULL,  BDISCHRED ,  2011-11-10 11:08:08.537 ,  Discharged ,  SERIES )

;WITH OrderedTable AS
(
    SELECT  Unit
            , IDNumber
            , EnteredDateTime
            , ROW_Number() OVER (Partition BY Unit ORDER BY Unit) RN 
    FROM    @t -- YOUR TABLE NAME GOES HERE
)
SELECT  t1.Unit
        , t1.IDNumber
        , t1.EnteredDateTime as TimeIn
        , t2.EnteredDateTime as TimeOut
        , DATEDIFF(hour, t1.EnteredDateTime, t2.EnteredDateTime ) TimeElapsedInHours
FROM    OrderedTable t1
JOIN    OrderedTable t2 ON t1.Unit = t2.Unit AND t2.RN = t1.RN + 1
WHERE   t1.RN % 2 <> 0