Select part of duration that occurs in specific hour of day - sql-server

Question

In SQL Server, I have a table of processes with a starttime and an endtime, from which I can calculate a duration using DATEDIFF.
Name StartTime EndTime
------------------------------------------------
process1 2016-10-10 11:10 2016-10-10 11:20
process2 2016-10-10 11:40 2016-10-10 12:30
How can I select the timespan of the process duration that occured in specific hours of the day (11 and 12) in seconds?
So process1 would be 10 minutes in hour 11.
process2 would be 20 minutes in hour 11, 30 minutes in hour 12.

Answer 1

Here's a sample that will generate hourly records for each source record. It uses a recursive CTE to move from the StartTime of each record through the EndTime. It may need some slight modifications to make it work in your case, but hopefully you can get the idea of how this method works.
Note that, as shown in the sample below, this will work properly even if the time span crosses a date boundary.
--==================================================================================
-- Do some quick setup to get a temporary table populated with data to use:
--==================================================================================
IF OBJECT_ID('tempdb..#ProcessHistory', 'U') IS NOT NULL DROP TABLE #ProcessHistory;
CREATE TABLE #ProcessHistory (
Name VARCHAR(20),
StartTime DATETIME,
EndTime DATETIME
)
INSERT INTO #ProcessHistory
VALUES ('process1', '2016-10-10 11:10', '2016-10-10 11:20'),
('process2', '2016-10-10 11:40', '2016-10-10 12:30'),
('process3', '2016-10-10 22:21', '2016-10-11 02:36');
--==================================================================================
-- Use a recursive CTE to generate hourly data for each record:
--==================================================================================
WITH HourlyData AS (
-- Anchor:
SELECT
ph.Name [ProcessName],
ph.StartTime [StartTime],
ph.EndTime [EndTime],
-- Get the current hour with date:
DATEADD(MINUTE, -DATEPART(MINUTE, ph.StartTime), ph.StartTime) [CurrentHour],
-- Calculate the next hour for use later:
DATEADD(MINUTE, 60 - DATEPART(MINUTE, ph.StartTime), ph.StartTime) [NextHour],
-- Determine how many minutes the process was active this hour:
CASE
WHEN DATEDIFF(MINUTE, ph.StartTime, ph.EndTime) > 60 - DATEPART(MINUTE, ph.StartTime)
THEN 60 - DATEPART(MINUTE, ph.StartTime)
ELSE DATEDIFF(MINUTE, ph.StartTime, ph.EndTime)
END [Minutes]
FROM #ProcessHistory ph
UNION ALL
-- Recurse:
SELECT
hd.ProcessName,
hd.StartTime,
hd.EndTime,
hd.NextHour [CurrentHour],
DATEADD(HOUR, 1, hd.NextHour) [NextHour],
-- Determine how many minutes the process was active this hour:
CASE
WHEN DATEDIFF(MINUTE, hd.NextHour, hd.EndTime) < 60
THEN DATEDIFF(MINUTE, hd.NextHour, hd.EndTime)
ELSE 60
END
FROM HourlyData hd
WHERE hd.NextHour < hd.EndTime
)
SELECT
hd.ProcessName,
hd.CurrentHour [HourWithDate],
CONVERT(DATE, hd.CurrentHour) [Date],
DATEPART(HOUR, hd.CurrentHour) [Hour],
hd.Minutes
FROM HourlyData hd
ORDER BY
hd.ProcessName,
hd.CurrentHour;
The output from the above sample would look like this:
ProcessName HourWithDate Date Hour Minutes
process1 2016-10-10 11:00:00.000 2016-10-10 11 10
process2 2016-10-10 11:00:00.000 2016-10-10 11 20
process2 2016-10-10 12:00:00.000 2016-10-10 12 30
process3 2016-10-10 22:00:00.000 2016-10-10 22 39
process3 2016-10-10 23:00:00.000 2016-10-10 23 60
process3 2016-10-11 00:00:00.000 2016-10-11 0 60
process3 2016-10-11 01:00:00.000 2016-10-11 1 60
process3 2016-10-11 02:00:00.000 2016-10-11 2 36

Answer 2

To handle general cases, you could try something like
--drop table #processes
CREATE TABLE #processes
(
name varchar(50),
StartTime Datetime,
EndTime DateTime
);
insert #processes VALUES('proc1','20161010 11:10','20161010 11:20');
insert #processes VALUES('proc2','20161010 11:40','20161010 12:20');
insert #processes VALUES('proc3','20161010 10:40','20161010 12:20');
;WITH HRS AS (SELECT 0 HR
UNION ALL
SELECT HR + 1 FROM HRS WHERE HR < 23),
MINS AS (SELECT 0 MN
UNION ALL
SELECT MN + 1 FROM MINS WHERE MN < 59),
TIMES AS (SELECT HR,MN FROM HRS CROSS JOIN MINS)
SELECT name,starttime,endtime,Count(0) AS mins FROM #processes
JOIN TIMES
ON (HR > datepart(hh,Starttime)
OR HR = datepart(hh,Starttime) AND MN >= datepart(n,STARTtIME))
AND
(HR < datepart(hh, EndTime)
OR HR = datepart(hh, EndTime) AND MN < datepart(n,EndTime))
WHERE HR = 11 --hour is 11
GROUP BY name,
starttime,
endtime
drop table #processes;

Answer 3

create table #temp (Name varchar(5), starttime datetime, EndTime datetime)
insert into #temp values(1,'2016-10-10 11:10','2016-10-10 11:20' )
insert into #temp values(2,'2016-10-10 11:40','2016-10-10 12:30' )
insert into #temp values(2,'2016-10-10 10:40','2016-10-10 11:30' )
insert into #temp values(2,'2016-10-10 10:40','2016-10-10 12:30' )
DECLARE #firstTime time ,#secondTime time
set #firstTime ='11:00'
set #secondTime ='12:00'
select
CASE WHEN CONVERT(time(0), starttime) < #firstTime AND CONVERT(time(0), EndTime) > #secondTime THEN DATEDIFF(ss,#firstTime,#secondTime)
WHEN CONVERT(time(0), EndTime) > #secondTime THEN DATEDIFF(ss,CONVERT(time(0), starttime),#secondTime)
WHEN CONVERT(time(0), starttime) < #firstTime THEN DATEDIFF(ss,CONVERT(time(0), EndTime),#secondTime)
ELSE DATEDIFF(ss,starttime,EndTime)
END
from #temp

Answer 4

SELECT CAST(DATEADD(MINUTE,DATEDIFF(MINUTE,'2016-10-10 11:10','2016-10-10 12:20'),'2011-01-01 00:00:00.000') AS TIME)
as timeDifference
With timeDifference -
SELECT CAST(DATEADD(MINUTE,DATEDIFF(MINUTE,StartTime,EndTime),'2011-01-01 00:00:00.000') AS TIME)
as timeDifference
from #YourTableName
With Days and TimeDiffernece
declare #start_time as varchar(150);
declare #end_time as varchar(150);
set #start_time='2016-10-10 10:10';
set #end_time='2016-10-12 12:10'
SELECT datediff(day,#start_time,#end_time) as dayDifference,
CAST(DATEADD(MINUTE,DATEDIFF(MINUTE,#start_time,#end_time),'2011-01-01 00:00:00') AS TIME(0))
as timeDifference

Answer 5

I think this does the trick, but it's pretty ugly. Maybe someone can do it more elegantly?
SELECT
case
when HOUR(starttime) < 11 AND HOUR(endtime) = 11 then minute(endtime)
when HOUR(starttime) < 11 AND HOUR(endtime) > 11 then 60
when HOUR(starttime) = 11 AND HOUR(endtime) = 11 then minute(endtime) - minute(starttime)
when HOUR(starttime) = 11 AND HOUR(endtime) > 11 then 60 - minute(starttime)
else 0
end AS ProcessTimeHour_11,
case
when HOUR(starttime) < 12 AND HOUR(endtime) = 12 then minute(endtime)
when HOUR(starttime) < 12 AND HOUR(endtime) > 12 then 60
when HOUR(starttime) = 12 AND HOUR(endtime) = 12 then minute(endtime) - minute(starttime)
when HOUR(starttime) = 12 AND HOUR(endtime) > 12 then 60 - minute(starttime)
else 0
end AS ProcessTimeHour_12
from StuffAndThings