DAY shift calculations - sql-server

Question

Input table
Start time End Time
8/12/14 17:00 8/14/14 12:00
I need to show the output as below
Date 11:00 to 23:00 23:00 to 11:00
8/12/14 6 1
8/13/14 12 12
8/14/14 1 11
I know you all will say "What did you try ?"
But the answer "I Can't think of where to start"

Answer 1

Using recursive CTE:
SQL Fiddle
MS SQL Server 2012 Schema Setup:
Query 1:
DECLARE #StartDate DateTime = '2014-08-12 17:00'
DECLARE #EndDate DateTime = '2014-08-14 12:00'
;WITH CTE
AS
(
SELECT #StartDate AS [Date],
CAST(#StartDate As time) AS [Time]
UNION ALL
SELECT DATEADD(HH, 1, [Date]) As [Date],
CAST(DATEADD(HH, 1, [Date]) AS Time) AS [Time]
FROM CTE
WHERE DATEADD(HH, 1, [Date]) < #EndDate
)
SELECT CAST([Date] AS Date) [Date],
SUM(CASE WHEN [Time] BETWEEN '11:00' AND '22:59'
THEN 1 ELSE 0 END) as [11:00 to 23:00],
SUM(CASE WHEN [Time] BETWEEN '00:00' AND '10:59'
THEN 1
WHEN [Time] Between '23:00' and '23:59' THEN 1
ELSE 0 END) as [23:00 to 11:00]
FROM CTE
GROUP BY CAST([Date] AS Date)
ORDER BY [Date]
Results:
| DATE | 11:00 TO 23:00 | 23:00 TO 11:00 |
|------------|----------------|----------------|
| 2014-08-12 | 6 | 1 |
| 2014-08-13 | 12 | 12 |
| 2014-08-14 | 1 | 11 |

Answer 2

The following shows one way to do with using a Tally tables (aka "table of numbers" table.)
Key assumptions I made:
Start and End times are both known
Start and End times are for precise hours (e.g. 1:00, 2:00, and not 13:23 or 00:00.00.007). (This is why I used the smalldatetime datatype)
End time is always greater than Start time
I went further and assumed that the data is stored in a table for multiple entities--that is, you'd ultimately want to process multiple items in one query. If you only ever want to do this for one item at a time, (a) the query below can be readily chopped down, and (b) it'd probably be easier to do in C# or whatever the calling language is.
Setting up testing data:
-- DROP TABLE Testing
CREATE TABLE Testing
(
EntryId int not null
,StartTime smalldatetime not null
,EndTime smalldatetime not null
)
INSERT Testing values
(1, 'Aug 12, 2014 17:00', 'Aug 14, 2014 12:00') -- Original problem
,(2, 'Aug 11, 2014 00:00', 'Aug 11, 2014 23:00') -- 23 hours
,(3, 'Aug 11, 2014 00:00', 'Aug 12, 2014 00:00') -- 24 hour shift
,(4, 'Aug 11, 2014 12:00', 'Aug 12, 2014 12:00') -- Noon to Noon
,(11, 'Aug 22, 2014 4:00', 'Aug 22, 2014 5:00') -- One-hour problem cases
,(12, 'Aug 22, 2014 10:00', 'Aug 22, 2014 11:00') -- One-hour problem cases
,(13, 'Aug 22, 2014 11:00', 'Aug 22, 2014 12:00') -- One-hour problem cases
,(14, 'Aug 22, 2014 12:00', 'Aug 22, 2014 13:00') -- One-hour problem cases
,(21, 'Aug 23, 2014 18:00', 'Aug 23, 2014 19:00') -- One-hour problem cases
,(22, 'Aug 23, 2014 22:00', 'Aug 23, 2014 23:00') -- One-hour problem cases
,(23, 'Aug 23, 2014 23:00', 'Aug 24, 2014 00:00') -- One-hour problem cases
,(24, 'Aug 24, 2014 00:00', 'Aug 24, 2014 1:00') -- One-hour problem cases
My routine:
DECLARE
#Earliest smalldatetime
,#Latest smalldatetime
-- This could be thrown in as a first CTE, but doing so would make the overall query that much less comprehensible.
SELECT
#Earliest = min(StartTime)
,#Latest = max(EndTime)
from Testing
--where <filtering criteria, if you're not parsing the whole table)
;WITH
Pass0 as (select 1 as C union all select 1), --2 rows
Pass1 as (select 1 as C from Pass0 as A, Pass0 as B),--4 rows
Pass2 as (select 1 as C from Pass1 as A, Pass1 as B),--16 rows
Pass3 as (select 1 as C from Pass2 as A, Pass2 as B),--256 rows
Pass4 as (select 1 as C from Pass3 as A, Pass3 as B),--65536 rows
Tally as (select row_number() over(order by C) as Number from Pass4),
DateRange as (select
dateadd(hh, ta.Number, #Earliest) ShiftHour
from Tally ta
where dateadd(hh, ta.Number, #Earliest) <= #Latest)
SELECT
te.EntryId
,cast(dateadd(hh, -1, dr.Shifthour) as date) [Date]
,sum(case when datepart(hh, dateadd(hh, -1, dr.Shifthour)) between 11 and 22 then 1 else 0 end) [11:00 to 23:00]
,sum(case when datepart(hh, dateadd(hh, -1, dr.Shifthour)) between 11 and 22 then 0 else 1 end) [23:00 to 11:00]
from Testing te
inner join DateRange dr
on dr.ShiftHour > te.StartTime
and dr.ShiftHour <= te.Endtime
group by
te.EntryId
,cast(dateadd(hh, -1, dr.Shifthour) as date)
order by
te.EntryId
,cast(dateadd(hh, -1, dr.Shifthour) as date)
Plug this in to show the results without the grouping, invaluable in figuring out what's going on in there:
;WITH
Pass0 as (select 1 as C union all select 1), --2 rows
Pass1 as (select 1 as C from Pass0 as A, Pass0 as B),--4 rows
Pass2 as (select 1 as C from Pass1 as A, Pass1 as B),--16 rows
Pass3 as (select 1 as C from Pass2 as A, Pass2 as B),--256 rows
Pass4 as (select 1 as C from Pass3 as A, Pass3 as B),--65536 rows
Tally as (select row_number() over(order by C) as Number from Pass4),
DateRange as (select
dateadd(hh, ta.Number, #Earliest) ShiftHour
from Tally ta
where dateadd(hh, ta.Number, #Earliest) <= #Latest)
SELECT
te.EntryId
,dateadd(hh, -1, dr.Shifthour)
,cast(dateadd(hh, -1, dr.Shifthour) as date) [Date]
,datepart(hh, dateadd(hh, -1, dr.Shifthour))
from Testing te
inner join DateRange dr
on dr.ShiftHour > te.StartTime
and dr.ShiftHour <= te.Endtime
order by
te.EntryId
,cast(dateadd(hh, -1, dr.Shifthour) as date)
,dateadd(hh, -1, dr.Shifthour)
The hard parts were:
Getting the 24th hour (Aug 23, 00:00) into the previous day (Aug 24). That's why I shift everything back one day [edit] one HOUR
< and > logic when dealing with multiple entries
Reconciling with the fact that the results for a "One day Noon to Noon" sample just looks goofy.
Yeah, this may be over-engineering, but some times you just have to give it a try. I couldn't say how well it would perform on large datasets, and if your first and last dates are more than four years apart you'll need to add "Pass5" when building the tally table.

Answer 3

DECLARE #StartTime DATETIME='08/01/2013 00:00:00'
,#EndTime DATETIME='08/03/2013 23:00:00'
DECLARE #StartDate DATE,
#Starthour INT,
#Startmin INT,
#EndDate DATE,
#Endhour INT,
#Endmin INT
SELECT #StartDate=CONVERT(DATE,#StartTime,101),#Starthour=DATEPART(HOUR,#StartTime),#Startmin=DATEPART(MINUTE,#StartTime)
SELECT #EndDate=CONVERT(DATE,#EndTime,101),#Endhour=DATEPART(HOUR,#EndTime),#Endmin=DATEPART(MINUTE,#EndTime)
DECLARE #T TABLE (StartTime DATETIME, EndTime DATETIME)
INSERT #T VALUES (DATEADD(MINUTE,-#Startmin,#StartTime), DATEADD(MINUTE,-#Endmin,#EndTime))
DECLARE #Final1 TABLE (ShiftDate DATETIME,[11:00 to 23:00] INT,[23:00 to 11:00] INT)
DECLARE #Final2 TABLE (ShiftDate DATETIME,[11:00 to 23:00] INT,[23:00 to 11:00] INT)
DECLARE #Final3 TABLE (ShiftDate DATETIME,[11:00 to 23:00] INT,[23:00 to 11:00] INT)
;WITH CTE AS
(
SELECT StartTime AS dt, EndTime,StartTime
FROM #T
UNION ALL
SELECT DATEADD(MINUTE, 60, dt) AS dt, EndTime,DATEADD(MINUTE, 60,StartTime) AS StartTime
FROM CTE
WHERE dt < DATEADD(HOUR, -1, EndTime)
)
INSERT INTO #Final1([11:00 to 23:00],[23:00 to 11:00],ShiftDate)
SELECT
CASE
WHEN CAST(dt AS TIME) >= '11:00' AND CAST(dt AS TIME) < '23:00' THEN 1
ELSE 0
END AS '11:00 to 23:00',
CASE
WHEN CAST(dt AS TIME) >= '11:00' AND CAST(dt AS TIME) < '23:00' THEN 0
ELSE 1
END AS '23:00 to 11:00'
,StartTime
FROM CTE
INSERT INTO #Final2([11:00 to 23:00],[23:00 to 11:00],ShiftDate)
SELECT SUM([11:00 to 23:00])*60 AS [11:00 to 23:00]
,SUM([23:00 to 11:00])*60 AS [23:00 to 11:00]
,CONVERT(DATE,DATEADD(MINUTE,-660,ShiftDate)) AS ShiftDate
FROM #Final1
GROUP BY CONVERT(DATE,DATEADD(MINUTE,-660,ShiftDate))
INSERT INTO #Final3([11:00 to 23:00],[23:00 to 11:00],ShiftDate)
SELECT CASE WHEN ShiftDate=#StartDate AND #Starthour BETWEEN 11 AND 22 THEN [11:00 to 23:00]-#Startmin ELSE [11:00 to 23:00] END AS [11:00 to 23:00],
CASE WHEN ShiftDate=#StartDate AND #Starthour BETWEEN 23 AND 10 THEN [23:00 to 11:00]-#Startmin ELSE [23:00 to 11:00] END AS [23:00 to 11:00],
ShiftDate
FROM #Final2
SELECT ShiftDate,
CONVERT(VARCHAR(10),
(CASE WHEN ShiftDate=#EndDate AND #Endhour BETWEEN 11 AND 22
THEN [11:00 to 23:00]+#Endmin
ELSE [11:00 to 23:00] END)) AS [11:00 to 23:00],
CONVERT(VARCHAR(10),
(CASE WHEN ShiftDate=#EndDate AND #Endhour BETWEEN 23 AND 10
THEN [23:00 to 11:00]+#Endmin
ELSE [23:00 to 11:00] END)) AS [23:00 to 11:00]
FROM #Final3