Calculating time in a price list - sql

Question

I have a Price list table in SQL Server 2008R2 and want to calculate the Price for a Service according to the time where the Service has been made.
timefrom |timeto |Price
-------- |------ |-----
1900-01-01 00:00:00|1900-01-01 07:00:00|20.00
1900-01-01 07:00:00|1900-01-01 19:00:00|15.00
1900-01-01 19:00:00|1900-01-02 00:00:00|20.00
This pricelist Shows different Price during night time starting at 19:00 and Lasting until 07.00 AM and daytime from 07:00 to 19:00.
Minutes have to be rounded up and down to quarter hours.
There is some more to take care of, such as Minimum notice Periode (#Vorlaufzeit) and if weekday of Weekend. Both conditions are met and not the Problem. My Problem is the first and the last record, where I have to round up and/or round down, which are incorrect. Both lines have 1 in the loop and should be corrected correctly in the both updates, but does not.
So, for example a Service from 2016-11-04 10:50 (rounding down to 10:45 which is 0.25 hours) to 2016-11-04 19:25 (rounded up to 19:30 which is 0.5 hours) is 0.25+8+0.5= 8.75 hours and costs 8.25*15 + 0.5*20 = 133.75.
I tried with this code, but it does not bring me the correct result. It is only the first and the last record where I have to round up or down. It is only correct, when there are full hours.
DECLARE #Dauer int
DECLARE #X int --Loopcounter für Stunden
declare #Y int --Loopcounter für Tageszahler
declare #Anfangszeit datetime
declare #Anfangsstunde datetime
declare #Endzeit datetime
declare #Vorlaufzeit int --in Minuten
declare #ErsteZeitvon datetime
declare #SummeAnzStunden decimal(8,2)
declare #MinimumZeit int
declare #ZeitvonVolleStunde int -- aus 07:25 mach 7 Uhr
declare #ZeitbisVolleStunde int
declare #AnfangsDatumZeit as datetime
declare #EndDatumZeit as datetime
declare #AnfangsDatumZeitLoop as datetime
declare #AnfangsZeitLoop as datetime
declare #TagesZaehler int
set #AnfangsDatumZeit = #Datumvon+#Zeitvon
set #EndDatumZeit = #Datumbis+#Zeitbis
set #Tageszaehler=datediff(day,#AnfangsDatumZeit, #EndDatumZeit)
declare #t1 table ( PreisID int, AnzStunden decimal(5,2), Preis decimal(8,2), Anfangszeit datetime, Prüfzeit datetime, startzeit datetime, endezeit datetime, Vorlaufzeit int, Dauer int, PreisFT decimal(8,2), DatZeitvon datetime, DatZeitbis datetime, Tageszaehler int )
-- Insert statements for procedure here
set #ZeitvonVolleStunde=Datediff(hour, '00:00:00', #Zeitvon)
set #ZeitbisVolleStunde=Datediff(minute, '00:00:00', #Zeitbis)
set #Dauer=ceiling(Datediff(minute, #AnfangsDatumZeit, #EndDatumZeit)/60.00)
set #Vorlaufzeit=datediff(minute,#Bestelldatum, #AnfangsDatumZeit)
SET #X = 0
if Datediff(minute, #AnfangsDatumZeit, #EndDatumZeit) > 360
begin
WHILE (#X <=#Dauer) --z.b. 13
begin
--set #Y = datediff(day,#AnfangsDatumZeit,#AnfangsDatumZeitLoop)
set #Y = datediff(day,#AnfangsDatumZeit,dateadd(hour,#X, #AnfangsDatumZeit))
set #AnfangsDatumZeitLoop=dateadd(hour,#X, #AnfangsDatumZeit)
set #AnfangsZeitLoop=dateadd(hour,#X, #Zeitvon)
insert into #t1 ( PreisID, AnzStunden, Preis , Anfangszeit, Prüfzeit, DatZeitvon , DatZeitbis )
SELECT top 1 preisID, 1, Preis, #AnfangsZeitLoop, #AnfangsDatumZeitLoop, Zeitvon, Zeitbis
FROM dbo.Mypricetable
where SdlID=#Leistungsart --SdlID
and Wochentag=case when DATEPART(dw,#AnfangsDatumZeitLoop) < 6 then 'W' else 'S' end --Wochentag
and #Vorlaufzeit BETWEEN Vorlaufzeitvon and Vorlaufzeitbis --Vorlaufzeit in Minuten
AND #Dauer*60 BETWEEN Dauervon AND Dauerbis --DauerInMinuten
and #AnfangsZeitLoop between Zeitvon and Zeitbis --sucht die von/bis Zeitgruppe
order by zeitvon
SET #X = #X + 1
end
--check and udate of the first record in #t1 rounding down to 15 minutes
update #t1 set Anzstunden= Anzstunden + CONVERT(DECIMAL(6, 2), ROUND(((datediff(minute,[dbo].[sfRoundToHourParts](#AnfangsDatumZeit,1), [dbo].[sfRoundToHourParts](#AnfangsDatumZeit,4)) + 7) / 60.00) / 25, 2) * 25)
from #t1 c where c.Prüfzeit=(SELECT Top 1 Prüfzeit from #t1 order by Prüfzeit)
--check and udate of the last record in #t1 rounding up to 15 minutes
update #t1 set Anzstunden= round(convert(decimal(5,2),datepart(minute,#EndDatumZeit)+7)/60/25,2)*25
from #t1 c where c.Prüfzeit=(SELECT Top 1 Prüfzeit from #t1 order by Prüfzeit DESC)
end
select * from #t1 order by Prüfzeit
Thanks your help!
Michael

Answer 1

This code is a bit verbose, but wanted to share it with you as it produces the desired result of 133.75
DECLARE #x table (
timefrom datetime
, timeto datetime
, price decimal(14,4)
);
INSERT INTO #x (timefrom, timeto, price)
VALUES ('1900-01-01T00:00:00', '1900-01-01T07:00:00', 20.00)
, ('1900-01-01T07:00:00', '1900-01-01T19:00:00', 15.00)
, ('1900-01-01T19:00:00', '1900-01-02T00:00:00', 20.00)
;
-- You should have your own, physical tally table!
DECLARE #numbers table (
number tinyint
);
INSERT INTO #numbers (number)
SELECT DISTINCT
number
FROM master.dbo.spt_values
WHERE number BETWEEN 0 AND 255
;
DECLARE #start datetime = '2016-11-04T10:50:00'
, #end datetime = '2016-11-04T19:25:00'
;
-- first, let's do some rounding of our inputs
DECLARE #rounded_start_time time
, #rounded_end_time time
;
-- Illustrate the steps to round the time to quarters... this might not be the simplest method; but it works!
/*
SELECT #start AS start
, DateAdd(hh, DateDiff(hh, 0, #start), 0) AS truncate_hour
, Round(DatePart(mi, #start) / 15.0, 0) * 15 AS rounded_mins
, DateAdd(mi, Round(DatePart(mi, #start) / 15.0, 0) * 15, DateAdd(hh, DateDiff(hh, 0, #start), 0)) AS truncate_hour_then_add_mins
;
*/
SET #rounded_start_time = DateAdd(mi, Round(DatePart(mi, #start) / 15.0, 0) * 15, DateAdd(hh, DateDiff(hh, 0, #start), 0));
SET #rounded_end_time = DateAdd(mi, Round(DatePart(mi, #end ) / 15.0, 0) * 15, DateAdd(hh, DateDiff(hh, 0, #end ), 0));
PRINT 'Start: ' + Format(#rounded_start_time, 'HH:mm');
PRINT 'End: ' + Format(#rounded_end_time , 'HH:mm');
--SELECT *
--FROM #x
--;
; WITH intervals AS (
SELECT number * 15 AS minute_increments
, DateAdd(mi, number * 15, 0) AS interval_start
, DateAdd(mi, (number + 1) * 15, 0) AS interval_end
FROM #numbers
WHERE number >= 0
AND number < 24 * 4 --number of 15 minute increments in a day
)
, costed_intervals AS (
SELECT intervals.interval_start
, intervals.interval_end
, Cast(intervals.interval_start AS time) As interval_start_time
, Cast(intervals.interval_end AS time) As interval_end_time
, x.price / 4.0 AS interval_price
FROM #x AS x
INNER
JOIN intervals
ON intervals.interval_end <= x.timeto
AND intervals.interval_start >= x.timefrom
)
, applicable_intervals AS (
SELECT interval_start
, interval_end
, interval_start_time
, interval_end_time
, interval_price
FROM costed_intervals
WHERE interval_start_time < #rounded_end_time
AND interval_end_time > #rounded_start_time
)
SELECT Sum(interval_price) AS total_price
FROM applicable_intervals
;
This could use a lot of cleaning up and optimising.
It also only works when the start and end times are within the same day, among other bugs and fun stuff.

Answer 2

thanks to everyones contribution I could find my way and corrected my Duration and the two updates.
Duration:
set #Dauer=datediff(hh, DateAdd(hh, DateDiff(hh, 0, #Datumvon+#Zeitvon), 0),DateAdd(hh, DateDiff(hh, 0, #datumbis+#Zeitbis), 0))
Update the first record
update #t1 set Anzstunden =Anzstunden + (datediff(mi,DateAdd(mi, Round((DatePart(mi, #Zeitvon)-7) / 15.0, 0) * 15, DateAdd(hh, DateDiff(hh, 0, #Zeitvon), 0)),DateAdd(hh, DateDiff(hh, 0, #Zeitvon), 0))/60.00)
-- case when CONVERT(DECIMAL(6, 2), ROUND(((datediff(minute,[dbo].[sfRoundToHourParts](#AnfangsDatumZeit,1), [dbo].[sfRoundToHourParts](#AnfangsDatumZeit,4)) + 7) / 60.00) / 25, 2) * 25) *-1 > 0 then
-- CONVERT(DECIMAL(6, 2), ROUND(((datediff(minute,[dbo].[sfRoundToHourParts](#AnfangsDatumZeit,1), [dbo].[sfRoundToHourParts](#AnfangsDatumZeit,4)) + 7) / 60.00) / 25, 2) * 25) *-1 else Anzstunden end
from #t1 c where c.Prüfzeit=(SELECT Top 1 Prüfzeit from #t1 order by Prüfzeit)
Update the last record
--Prüft und korrigiert den LETZTEN Datensatz der #t1 auf 15 Minuten-Takt
update #t1 set Anzstunden= Anzstunden + ((datediff(mi,DateAdd(mi, Round((DatePart(mi, #Zeitbis)+7) / 15.0, 0) * 15, DateAdd(hh, DateDiff(hh, 0, #Zeitbis), 0)),DateAdd(hh, DateDiff(hh, 0, #Zeitbis), 0))/60.00)*-1)
from #t1 c where c.Prüfzeit=(SELECT Top 1 Prüfzeit from #t1 order by Prüfzeit DESC)
now everything is correct.
Thx to everyone.
Michael