How to display event hour by hour in SQL? - sql

Question

Create table tblEvent ( Event_ID int, Start_Time datetime, End_Time datetime )
insert into tblEvent values(1,'2015-02-10 9:00:00.000','2015-02-10 11:00:00.000')
insert into tblEvent values(2,'2015-02-10 11:00:00.000','2015-02-10 11:20:00.000')
insert into tblEvent values(3,'2015-02-10 11:20:00.000','2015-02-10 13:00:00.000')
and want to be display like below
Hour Event_ID [Start_End]
9 1 9:00-10:00
10 1 10:00-11:00
11 2 11:00-11:20
11 3 11:20-12:00
12 3 12:00-13:00
and we can make the End_Time of Event 3 become 13:30
we had to be display
13 3 13:00-13:30
Can anyone help me?

Answer 1

You can use DATEPART function
DATEPART(HOUR, [Start_End]) AS Hour

Answer 2

select blocks.Hour, e.Event_Id,
format(case when e.Start_Time > blocks.Start_Time then e.Start_Time else blocks.Start_Time end, 'HH:mm') +
'-' +
format(case when e.End_Time < blocks.End_Time then e.End_Time else blocks.End_Time end, 'HH:mm')
from
tblEvent as e inner join
(
select
d0.n + d1.n * 4 as Hour,
dateadd(hh, d0.n + d1.n * 4, cast(cast(current_timestamp as date) as datetime)) as Start_Time,
dateadd(hh, d0.n + d1.n * 4 + 1, cast(cast(current_timestamp as date) as datetime)) as End_Time
from
(select 0 as n union all select 1 union all select 2 union all select 3) as d0,
(select 0 as n union all select 1 union all select 2 union all select 3 union all select 4 union all select 5) as d1
) as blocks
on blocks.End_Time > e.Start_Time and blocks.Start_Time < e.End_Time
order by Event_Id, Hour
Here's a start. SQL Server? Is current day enough? You don't have the format() on SQL 2008 so you'll have to do that part yourself.
I'm not sure this handles all the cases exactly the way you want. You can take the basic idea and extend it across a longer range of hours, say 168 for a full week.
http://sqlfiddle.com/#!6/819c0/9

Answer 3

TRY Some thing like this.This sample data is running ok.
Please provide another sample data atleast 10 rows and don't forget to paste desired output.
Also read my comment in script.
DECLARE #tblEvent TABLE (
Event_ID INT
,Start_Time DATETIME
,End_Time DATETIME
)
INSERT INTO #tblEvent
VALUES (
1
,'2015-02-10 9:00:00.000'
,'2015-02-10 11:00:00.000'
)
,(
2
,'2015-02-10 11:00:00.000'
,'2015-02-10 11:20:00.000'
)
,(
3
,'2015-02-10 11:20:00.000'
,'2015-02-10 13:00:00.000'
);
--select *,DATEdiff(hour,a.Start_Time,a.End_Time) from #tblEvent a
;
WITH CTE
AS (
SELECT *
,ROW_NUMBER() OVER (
ORDER BY Start_Time
) RN
,DATEdiff(hour, Start_Time, End_Time) Diff
FROM #tblEvent
)
--select * from cte
,CTE1
AS (
SELECT Event_ID
,Start_Time
,CASE
WHEN Diff > 1
THEN DATEADD(minute, 60 - DATEPART(minute, Start_Time), Start_Time)
ELSE End_Time
END End_Time
,RN
,DIFF
,1 RN1
,DATEPART(minute, Start_Time) DIFFMIN
FROM CTE
--WHERE RN = 1
UNION ALL
SELECT CASE
WHEN A.Diff > B.DIFF
THEN b.Event_ID
ELSE a.Event_ID
END
,B.End_Time Start_Time
,CASE
WHEN A.Diff > B.DIFF
THEN DATEADD(minute, 60 - DATEPART(minute, B.Start_Time), B.End_Time)
ELSE A.End_Time
END End_Time
,CASE
WHEN A.Diff > B.DIFF
THEN B.RN
ELSE B.RN + 1
END RN
,CASE
WHEN A.Diff > B.DIFF
THEN B.DIFF - 1
ELSE A.Diff
END
,RN1 + 1
,0
FROM CTE1 B
CROSS APPLY (
SELECT *
FROM CTE
WHERE RN = B.RN
) A
WHERE B.DIFF > 0
)
SELECT [Hour]
,Event_ID
,[Start_End]
FROM (
SELECT DATEPART(HOUR, Start_Time) [Hour]
,ROW_NUMBER() OVER (
PARTITION BY Start_Time ORDER BY Start_Time
) RN2
,Event_ID
,CONVERT(VARCHAR(5), Start_Time, 114) + '-' + CONVERT(VARCHAR(5), End_Time, 114) [Start_End]
FROM CTE1
) TBL
WHERE RN2 = 1
--BELOW QUERY RETURN 6 ROWS
-- I AM TRYING TO ELIMINATE THE EXTRA ROWS WITHOUT ROW_NUMBER
--WHICH WOULD BE MORE OPTIMIZE,BUT I AM NOT GETTING WHAT ACTUALLY CAUSING THIS BEHAVIOUR
--MEANWHILE YOU CAN TEST OTHER SAMPLE DATA,AND THROW OTHER SAMPLE DATA
--SELECT DATEPART(HOUR, Start_Time) [Hour]
-- ,Event_ID
-- ,CONVERT(VARCHAR(5), Start_Time, 114) + '-' + CONVERT(VARCHAR(5), End_Time, 114) [Start_End]
-- FROM CTE1