Split datetime SQL Server 2008 - tsql

Question

I have a table with 3 columns StartDate, EndDate, ElapsedTimeInSec.
I use an AFTER INSERT trigger to calculate the ElapsedTimeInSec.
I would like to do this:
If my start date is 2011-11-18 07:30:00 and my end date 2011-11-18 9:30:00 which give me a ElapsedtimeInSec of 7200 I would like to be able to split it this way.
Row 1 : 2011-11-18 07:30:00 / 2011-11-18 08:00:00 / 1800
Row 2 : 2011-11-18 08:00:00 / 2011-11-18 09:00:00 / 3600
Row 3 : 2011-11-18 09:00:00 / 2011-11-18 09:30:00 / 1800
How can I achieve this result ?
I dont think I made my explaination clear enough.
I have an actual table with data in it which as 2 field one with a StratDowntime and one with a EndDowntime and I would like to create a view of hours per hour base on a production shift of 12 hours (07:00:00 to 19:00:00) of the downtime.
So If I have a downtime from 2011-11-19 06:00:00 to 2011-11-19 08:00:00 I want in my report to see from 07:00:00 so the new rocrd should look like 2011-11-19 07:00:00 to 2011-11-19 08:00:00.
Another example if I do have downtime from 2011-11-19 10:30:00 to 2011-11-19 13:33:00 I should get in my report this
- 2011-11-19 10:30:00 to 2011-11-19 11:00:00
- 2011-11-19 11:00:00 to 2011-11-19 12:00:00
- 2011-11-19 12:00:00 to 2011-11-19 13:00:00
- 2011-11-19 13:00:00 to 2011-11-19 13:33:00
I hope this will clarify the question because none of the solution down there is actually doing this it is close but not on it.
thanks

Answer 1

You could try something like:
DECLARE #StartDate DATETIME = '11/18/2011 07:30:00',
#EndDate DATETIME = '11/18/2011 09:30:00',
#Runner DATETIME
IF DATEDIFF (mi, #StartDate, #EndDate) < 60
BEGIN
SELECT #StartDate,
#EndDate,
DATEDIFF (s, #StartDate, #EndDate)
RETURN
END
SET #Runner = CONVERT (VARCHAR (10), #StartDate, 101) + ' ' + CAST (DATEPART(hh, #StartDate) + 1 AS VARCHAR) + ':00:00'
WHILE #Runner <= #EndDate
BEGIN
SELECT #StartDate,
#Runner,
DATEDIFF (s, #StartDate, #Runner)
SET #StartDate = #Runner
SET #Runner = DATEADD(hh, 1, #Runner)
END
SET #Runner = CONVERT (VARCHAR (10), #EndDate, 101) + ' ' + CAST (DATEPART(hh, #EndDate) AS VARCHAR) + ':00:00'
SELECT #Runner,
#EndDate,
DATEDIFF (s, #Runner, #EndDate)

Answer 2

CTE:
DECLARE #beginDate DATETIME,
#endDate DATETIME
SELECT #beginDate = '2011-11-18 07:30:00',
#endDate = '2011-11-18 09:33:10'
DECLARE #mytable TABLE
(
StartDowntime DATETIME,
EndDowntime DATETIME,
ElapsedDowntimesec INT
)
-- Recursive CTE
;WITH Hours
(
BeginTime,
EndTime,
Seconds
)
AS
(
-- Base case
SELECT #beginDate,
DATEADD(MINUTE, ( DATEPART(MINUTE, #beginDate) * -1 ) + 60, #beginDate),
DATEDIFF
(
SECOND,
#beginDate,
CASE
WHEN #endDate < DATEADD(MINUTE, ( DATEPART(MINUTE, #beginDate) * -1 ) + 60, #beginDate) THEN #endDate
ELSE DATEADD(MINUTE, ( DATEPART(MINUTE, #beginDate) * -1 ) + 60, #beginDate)
END
)
UNION ALL
-- Recursive
SELECT Hours.EndTime,
CASE
WHEN #endDate < DATEADD(MINUTE, ( DATEPART(MINUTE, Hours.BeginTime) * -1 ) + 120, Hours.BeginTime) THEN #endDate
ELSE DATEADD(minute, ( DATEPART(MINUTE, Hours.BeginTime) * -1 ) + 120, Hours.BeginTime)
END,
DATEDIFF
(
SECOND,
Hours.EndTime,
CASE
WHEN #endDate < DATEADD(MINUTE, ( DATEPART(MINUTE, Hours.BeginTime) * -1 ) + 120, Hours.BeginTime) THEN #endDate
ELSE DATEADD(MINUTE, ( DATEPART(MINUTE, Hours.BeginTime) * -1 ) + 120, Hours.BeginTime)
END
)
FROM Hours
WHERE Hours.BeginTime < #endDate
)
INSERT INTO #myTable
SELECT *
FROM Hours
WHERE BeginTime < #endDate
SELECT * FROM #myTable
Results
BeginTime EndTime Seconds
2011-11-18 07:30:00.000 2011-11-18 08:00:00.000 1800
2011-11-18 08:00:00.000 2011-11-18 09:00:00.000 3600
2011-11-18 09:00:00.000 2011-11-18 09:33:10.000 1990

Answer 3

You can use a table valued function applied like SELECT * FROM [dbo].split('2011-11-02 12:55:00','2011-11-02 13:05:00')
Function defintion:
CREATE FUNCTION [dbo].[split] (#d1 DATETIME, #d2 DATETIME)
RETURNS #result TABLE (
StartDate DATETIME,
EndDate DATETIME,
ElapsedTimeSeconds INT
)
AS
BEGIN
-- Store intermediate values in #tmp, using ix as driver for start times.
DECLARE #tmp TABLE (ix INT NOT NULL IDENTITY(0,1) PRIMARY KEY
, d1 DATETIME, d2 DATETIME)
-- Insert first hole hour lower than start time
INSERT INTO #tmp (d1) SELECT DATEADD(HOUR, DATEDIFF(HOUR, -1, #d1), -1)
-- Calculate expected number of intervals
DECLARE #intervals INT = DATEDIFF(HOUR, #d1, #d2) - 1
-- insert all intervals
WHILE #intervals > 0
BEGIN
INSERT INTO #tmp (d1, d2) select top 1 d1, d2 FROM #tmp
SET #intervals = #intervals - 1
END
-- Set start and end time for all whole hour intervals
UPDATE #tmp SET d1 = DATEADD(hour, ix, d1)
, d2 = DATEADD(hour, ix + 1, d1)
-- Set correct start time for first interval
UPDATE #tmp SET d1 = #d1 WHERE d1 <= #d1
-- Insert end interval
INSERT INTO #tmp (d1, d2)
SELECT MAX(d2), #d2 FROM #tmp
-- Delete non-empty last interval
DELETE FROM #tmp WHERE d1 = d2
-- Insert #tmp to #result
INSERT INTO #result (StartDate, EndDate)
SELECT d1, d2 FROM #tmp
-- Set interval lengths
UPDATE #result SET ElapsedTimeSeconds = DATEDIFF(second, StartDate, EndDate)
return
END
GO
To get a result from an existing table, you can use CROSS APPLY. Assuming a table YourTable with StartTime and EndTime you can do something like
SELECT s.*, y.* FROM YourTable y
cross apply dbo.split(y.StartTime, y.EndTime) s
WHERE y.EndTime < '2011-09-11'
to get a result with a kind of join between input data and output table.