Querying two time columns for sum of datediff
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Hi,
I have a table with two columns of datetime. The first is considered the 'startdate' and the second the 'enddate' time.
I want to capture the SUM of the DATEDIFF between all the ons to off and can do so by:
SELECT ISNULL(SUM(DATEDIFF(second,startdate,enddate) /60.0),0)
WHERE startdate > xxxx and enddate < xxxxx
Is there a way to do the same but take into account should the start or end date (xxxx) for the query cross a record. I.e. if the start date for the query was 0101/12 10:00 and there is a row of
startdate: 0101/12 08:00 enddate 0101/12 12:00
this row would be ignored but I would want the 2 hours 10-12 to be included, same would apply for an overlap on the end date. (just to complicate things the query would need to be able to handle the start xxxx and end xxx both being in the 'middle' of one row and returning basically the DATEDIFF of start xxxx and end xxx as the result.
Any shove in the right direction welcome 🙂
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DECLARE @T TABLE(StartDate DATETIME,
EndDate DATETIME,
Comments VARCHAR(255));
INSERT INTO @T VALUES ('2013-01-01 08:00', '2013-01-01 16:00', 'Overlapping Both Ends');
INSERT INTO @T VALUES ('2013-01-01 08:00', '2013-01-01 12:00', 'Overlapping Front');
INSERT INTO @T VALUES ('2013-01-01 13:00', '2013-01-01 18:00', 'Overlapping End');
INSERT INTO @T VALUES ('2013-01-01 11:00', '2013-01-01 13:00', 'Not Overlapping');
DECLARE @StartDate DATETIME = '2013-01-01 10:00',
@EndDate DATETIME = '2013-01-01 14:00';
SELECT
SUM(CASE
WHEN StartDate < @StartDate AND EndDate > @EndDate THEN DATEDIFF(SECOND, @StartDate, @EndDate)
WHEN StartDate >= @StartDate AND EndDate <= @EndDate THEN DATEDIFF(SECOND, StartDate, EndDate)
WHEN StartDate < @StartDate THEN DATEDIFF(SECOND, @StartDate, EndDate)
WHEN EndDate > @EndDate THEN DATEDIFF(SECOND, StartDate, @EndDate)
END * 60.)
FROM
@T;
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Sean,
That is absolutely brilliant. Thank you so much. I should have tried this forum before wasting around 3 days and getting nowhere!!!!!! I have modified the code with some extras to suit the last row where the off time has not net been recored.
DECLARE @T TABLE(StartDate DATETIME,
EndDate DATETIME,
Comments VARCHAR(255));
INSERT INTO @T VALUES ('2013-01-01 01:00', '2013-01-01 04:00', 'Not needed');
INSERT INTO @T VALUES ('2013-01-01 08:00', '2013-01-01 16:00', 'Overlapping Both Ends');
INSERT INTO @T VALUES ('2013-01-01 08:00', '2013-01-01 12:00', 'Overlapping Front');
INSERT INTO @T VALUES ('2013-01-01 13:00', '2013-01-01 18:00', 'Overlapping End');
INSERT INTO @T VALUES ('2013-01-01 11:00', '2013-01-01 13:00', 'Not Overlapping');
INSERT INTO @T VALUES ('2013-01-01 11:00', NULL, 'Not Overlapping');
INSERT INTO @T VALUES ('2013-01-01 16:00', '2013-01-01 20:00', 'Not needed');
DECLARE @StartDate DATETIME
SET @StartDate = '2013-01-01 10:00'
DECLARE @EndDate DATETIME
SET @EndDate= '2013-01-01 14:00';
SELECT
SUM(CASE
WHEN StartDate < @StartDate AND EndDate > @EndDate THEN DATEDIFF(SECOND, @StartDate, @EndDate)--Area4
WHEN StartDate >= @StartDate AND EndDate <= @EndDate THEN DATEDIFF(SECOND, StartDate, EndDate)
WHEN StartDate < @StartDate AND EndDate < @EndDate AND EndDate > @StartDate THEN DATEDIFF(SECOND, @StartDate, EndDate)
WHEN StartDate > @StartDate AND StartDate < @EndDate AND EndDate > @EndDate THEN DATEDIFF(SECOND, StartDate, @EndDate)
WHEN StartDate > @StartDate AND EndDate IS NULL THEN DATEDIFF(SECOND, StartDate, @Enddate)
WHEN StartDate < @StartDate AND EndDate IS NULL THEN DATEDIFF(SECOND, @StartDate, @Enddate)
END / 60.)
FROM
@T;
Thanks again Sean.
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You are welcome.
You can also use ISNULL instead of creating a new condition.
DECLARE @T TABLE(StartDate DATETIME,
EndDate DATETIME,
Comments VARCHAR(255));
INSERT INTO @T VALUES ('2013-01-01 01:00', '2013-01-01 04:00', 'Not needed');
INSERT INTO @T VALUES ('2013-01-01 08:00', '2013-01-01 16:00', 'Overlapping Both Ends');
INSERT INTO @T VALUES ('2013-01-01 08:00', '2013-01-01 12:00', 'Overlapping Front');
INSERT INTO @T VALUES ('2013-01-01 13:00', '2013-01-01 18:00', 'Overlapping End');
INSERT INTO @T VALUES ('2013-01-01 11:00', '2013-01-01 13:00', 'Not Overlapping');
INSERT INTO @T VALUES ('2013-01-01 11:00', NULL, 'Not Overlapping');
INSERT INTO @T VALUES ('2013-01-01 16:00', '2013-01-01 20:00', 'Not needed');
DECLARE @StartDate DATETIME
SET @StartDate = '2013-01-01 10:00'
DECLARE @EndDate DATETIME
SET @EndDate= '2013-01-01 14:00';
SELECT
SUM(CASE
WHEN StartDate < @StartDate AND ISNULL(EndDate, '2099-12-31') > @EndDate THEN DATEDIFF(SECOND, @StartDate, @EndDate)--Area4
WHEN StartDate >= @StartDate AND EndDate <= @EndDate THEN DATEDIFF(SECOND, StartDate, EndDate)
WHEN StartDate < @StartDate AND EndDate < @EndDate AND EndDate > @StartDate THEN DATEDIFF(SECOND, @StartDate, EndDate)
WHEN StartDate > @StartDate AND StartDate < @EndDate AND ISNULL(EndDate, '2099-12-31') > @EndDate THEN DATEDIFF(SECOND, StartDate, @EndDate)
END / 60.)
FROM
@T;
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