我有一个表，其中包含一个具有以下信息的时间序列。每条记录都代表“更改模式”事件。
Timestamp | Mode
------------------+------
2018-01-01 12:00 | 1
2018-01-01 18:00 | 2
2018-01-02 01:00 | 1
2018-01-02 02:00 | 2
2018-01-04 04:00 | 1
通过使用 LEAD 功能，我可以创建具有以下结果的查询。现在，每条记录都包含有关“模式已激活”的时间和时间的信息。
请检查第二和第四条记录。他们“属于”多天。
StartDT | EndDT | Mode | Duration
------------------+------------------+------+----------
2018-01-01 12:00 | 2018-01-01 18:00 | 1 | 6:00
2018-01-01 18:00 | 2018-01-02 01:00 | 2 | 7:00
2018-01-02 01:00 | 2018-01-02 02:00 | 1 | 1:00
2018-01-02 02:00 | 2018-01-04 04:00 | 2 | 50:00
2018-01-04 04:00 | (NULL) | 1 | (NULL)
现在，我想查询一个按日期和方式对数据进行分组并汇总持续时间的查询。
此结果表是必需的：
Date | Mode | Total
------------+------+-------
2018-01-01 | 1 | 6:00
2018-01-01 | 2 | 6:00
2018-01-02 | 1 | 1:00
2018-01-02 | 2 | 23:00
2018-01-03 | 2 | 24:00
2018-01-04 | 2 | 04:00
我不知道如何处理“属于”多天的记录。有什么想法吗？
答案 0 :(得分：2)
create table ChangeMode ( ModeStart datetime2(7), Mode int )
insert into ChangeMode ( ModeStart, Mode ) values
( '2018-11-15T21:00:00.0000000', 1 ),
( '2018-11-16T17:18:19.1231234', 2 ),
( '2018-11-16T18:00:00.5555555', 1 ),
( '2018-11-16T18:00:01.1234567', 2 ),
( '2018-11-16T19:02:22.8888888', 1 ),
( '2018-11-16T20:00:00.9876543', 2 ),
( '2018-11-17T09:00:00.0000000', 1 ),
( '2018-11-17T23:23:23.0230450', 2 ),
( '2018-11-19T17:00:00.0172839', 1 ),
( '2018-11-20T03:07:00.7033077', 2 )
;
with
-- Determine the earliest and latest dates.
-- Cast to date to remove the time portion.
-- Cast results back to datetime because we're going to add hours later.
MinMaxDates
as
(select cast(min(cast(ModeStart as date))as datetime) as MinDate,
cast(max(cast(ModeStart as date))as datetime) as MaxDate from ChangeMode),
-- How many days have passed during that period
Dur
as
(select datediff(day,MinDate,MaxDate) as Duration from MinMaxDates),
-- Create a list of numbers.
-- These will be added to MinDate to get a list of dates.
NumList
as
( select 0 as Num
union all
select Num+1 from NumList,Dur where Num<Duration ),
-- Create a list of dates by adding those numbers to MinDate
DayList
as
( select dateadd(day,Num,MinDate)as ModeDate from NumList, MinMaxDates ),
-- Create a list of day periods
PeriodList
as
( select ModeDate as StartTime,
dateadd(day,1,ModeDate) as EndTime
from DayList ),
-- Use LEAD to get periods for each record
-- Final record would return NULL for ModeEnd
-- We replace that with end of last day
ModePeriodList
as
( select ModeStart,
coalesce( lead(ModeStart)over(order by ModeStart),
dateadd(day,1,MaxDate) ) as ModeEnd,
Mode from ChangeMode, MinMaxDates ),
ModeDayList
as
( select * from ModePeriodList, PeriodList
where ModeStart<=EndTime and ModeEnd>=StartTime
),
-- Keep the later of the mode start time, and the day start time
-- Keep the earlier of the mode end time, and the day end time
ModeDayPeriod
as
( select case when ModeStart>=StartTime then ModeStart else StartTime end as StartTime,
case when ModeEnd<=EndTime then ModeEnd else EndTime end as EndTime,
Mode from ModeDayList ),
SumDurations
as
( select cast(StartTime as date) as ModeDate,
Mode,
DateDiff_Big(nanosecond,StartTime,EndTime)
/3600000000000
as DurationHours from ModeDayPeriod )
-- List the results in order
-- Use MaxRecursion option in case there are more than 100 days
select ModeDate as [Date], Mode, sum(DurationHours) as [Total Duration Hours]
from SumDurations
group by ModeDate, Mode
order by ModeDate, Mode
option (maxrecursion 0)
结果是：
Date Mode Total Duration Hours
---------- ----------- ---------------------------------------
2018-11-15 1 3.00000000000000
2018-11-16 1 18.26605271947221
2018-11-16 2 5.73394728052777
2018-11-17 1 14.38972862361111
2018-11-17 2 9.61027137638888
2018-11-18 2 24.00000000000000
2018-11-19 1 6.99999519891666
2018-11-19 2 17.00000480108333
2018-11-20 1 3.11686202991666
2018-11-20 2 20.88313797008333
答案 1 :(得分：1)
您可以使用CTE创建天数表，然后将时间段加入到表中
DECLARE @MAX as datetime2 = (SELECT MAX(CAST(Timestamp as date)) MX FROM process);
WITH StartEnd AS (select p1.Timestamp StartDT,
P2.Timestamp EndDT ,
p1.mode
from process p1
outer apply
(SELECT TOP 1 pOP.* FROM
process pOP
where pOP.Timestamp > p1.Timestamp
order by pOP.Timestamp asc) P2
),
CAL AS (SELECT (SELECT MIN(cast(StartDT as date)) MN FROM StartEnd) DT
UNION ALL
SELECT DATEADD(day,1,DT) DT FROM CAL WHERE CAL.DT < @MAX
),
TMS AS
(SELECT CASE WHEN S.StartDT > C.DT THEN S.StartDT ELSE C.DT END AS STP,
CASE WHEN S.EndDT < DATEADD(day,1,C.DT) THEN S.ENDDT ELSE DATEADD(day,1,C.DT) END AS STE
FROM StartEnd S JOIN CAL C ON NOT(S.EndDT <= C.DT OR S.StartDT>= DATEADD(day,1,C.dt))
)
SELECT *,datediff(MI ,TMS.STP, TMS.ste) as x from TMS
答案 2 :(得分：1)
以下内容使用递归CTE构建日期列表（日历或数字表效果很好）。然后，它将日期与日期时间相交，以便用匹配的数据填充缺少的日期。重要的一点是，对于每一行，如果开始日期时间属于前一天，则将其限制为00:00。结束日期时间也是如此。
DECLARE @t TABLE (timestamp DATETIME, mode INT);
INSERT INTO @t VALUES
('2018-01-01 12:00', 1),
('2018-01-01 18:00', 2),
('2018-01-02 01:00', 1),
('2018-01-02 02:00', 2),
('2018-01-04 04:00', 1);
WITH cte1 AS (
-- the min and max dates in your data
SELECT
CAST(MIN(timestamp) AS DATE) AS mindate,
CAST(MAX(timestamp) AS DATE) AS maxdate
FROM @t
), cte2 AS (
-- build all dates between min and max dates using recursive cte
SELECT mindate AS day_start, DATEADD(DAY, 1, mindate) AS day_end, maxdate
FROM cte1
UNION ALL
SELECT DATEADD(DAY, 1, day_start), DATEADD(DAY, 2, day_start), maxdate
FROM cte2
WHERE day_start < maxdate
), cte3 AS (
-- pull end datetime from next row into current
SELECT
timestamp AS dt_start,
LEAD(timestamp) OVER (ORDER BY timestamp) AS dt_end,
mode
FROM @t
), cte4 AS (
-- join datetime with date using date overlap query
-- then clamp start datetime to 00:00 of the date
-- and clamp end datetime to 00:00 of next date
SELECT
IIF(dt_start < day_start, day_start, dt_start) AS dt_start_fix,
IIF(dt_end > day_end, day_end, dt_end) AS dt_end_fix,
mode
FROM cte2
INNER JOIN cte3 ON day_end > dt_start AND dt_end > day_start
)
SELECT dt_start_fix, dt_end_fix, mode, datediff(minute, dt_start_fix, dt_end_fix) / 60.0 AS total
FROM cte4
答案 3 :(得分：0)
谢谢大家！
Cato 的答案使我走上了正确的轨道。这是我的最终解决方案：
DECLARE @Start AS datetime;
DECLARE @End AS datetime;
DECLARE @Interval AS int;
SET @Start = '2018-01-01';
SET @End = '2018-01-05';
SET @Interval = 24 * 60 * 60;
WITH
cteDurations AS
(SELECT [Timestamp] AS StartDT,
LEAD ([Timestamp]) OVER (ORDER BY [Timestamp]) AS EndDT,
Mode
FROM tblLog
WHERE [Timestamp] BETWEEN @Start AND @End
),
cteTimeslots AS
(SELECT @Start AS StartDT,
DATEADD(SECOND, @Interval, @Start) AS EndDT
UNION ALL
SELECT EndDT,
DATEADD(SECOND, @Interval, EndDT)
FROM cteTimeSlots WHERE StartDT < @End
),
cteDurationsPerTimesplot AS
(SELECT CASE WHEN S.StartDT > C.StartDT THEN S.StartDT ELSE C.StartDT END AS StartDT,
CASE WHEN S.EndDT < C.EndDT THEN S.EndDT ELSE C.EndDT END AS EndDT,
C.StartDT AS Slot,
S.Mode
FROM cteDurations S
JOIN cteTimeslots C ON NOT(S.EndDT <= C.StartDT OR S.StartDT >= C.EndDT)
)
SELECT Slot,
Mode,
SUM(DATEDIFF(SECOND, StartDT, EndDT)) AS Duration
FROM cteDurationsPerTimesplot
GROUP BY Slot, Mode
ORDER BY Slot, Mode;
使用变量 @Interval ，您可以定义时隙的大小。
CTE cteDurations 使用TSQL函数 LEAD （在MSSQL> = 2012中可用）创建带有所有必要条目持续时间的子结果。这将比OUTER APPLY快很多。
CTE cteTimeslots 生成包含开始时间和结束时间的时隙列表。
CTE cteDurationsPerTimesplot 是在cteDurations和cteTimeslots之间具有JOIN的子结果。这是 Cato 的神奇的JOIN语句！
最后，SELECT语句将按照插槽和模式进行分组和求和。
再次：非常感谢大家！特别是对卡托！你救了我的周末！
问候 奥利弗