Date and Time field query - sql-server

Question

If Date and Time field is having date entry like '2017-12-04 21:30:00.000' and Duration is '1800' and '2017-12-04 21:30:22.000' has '22' then our query should show record as '2017-12-04 21:30:00.000' as '1800' but 22 seconds should come at '2017-12-04 21:30:00.000' but my query is showing at 2017-12-04 21:00:00.000 with Duration as '1822' (sum of 1800+22). I have this question is this link in different manner but didn't get a proper answer hence asking this question here as I'm not able to modify in proper way.
Query:
SELECT Interval=(CASE WHEN datepart(MINUTE,[DateTime]) = 0 and datepart(SECOND,DateTime)=0 THEN
CAST(CONVERT(VARCHAR(30),DATEADD(HOUR,-1,[DateTime]),101) + ' '+ cast(format(DATEPART(HOUR,DATEADD(HOUR,-1,[DateTime])),'0#') as varchar)+':30:00' as DateTime)
ELSE (CAST(CONVERT(VARCHAR(30),[DateTime],101) +' ' + (case when datepart(MINUTE,[DateTime])<=30 and
datepart(SECOND,[DateTime])<59
then cast(format(DATEPART(HOUR,[DateTime]),'0#') as varchar)+':00:00'
else cast(format(DATEPART(HOUR,[DateTime]),'0#') as varchar)+':30:00' end) as DateTime)) END),
ID,Code,Duration=SUM(Duration) FROM Table
WHERE [DateTime] >= '2017-12-04 00:00:00' and [DateTime] <= '2017-12-04 23:59:59'
GROUP BY (CASE WHEN datepart(MINUTE,[DateTime]) = 0 and datepart(SECOND,DateTime)=0 THEN
CAST(CONVERT(VARCHAR(30),DATEADD(HOUR,-1,[DateTime]),101) + ' '+ cast(format(DATEPART(HOUR,DATEADD(HOUR,-1,[DateTime])),'0#') as varchar)+':30:00' as DateTime)
ELSE (CAST(CONVERT(VARCHAR(30),[DateTime],101) +' ' + (case when datepart(MINUTE,[DateTime])<=30 and
datepart(SECOND,[DateTime])<59 then cast(format(DATEPART(HOUR,[DateTime]),'0#') as varchar)+':00:00'
else cast(format(DATEPART(HOUR,[DateTime]),'0#') as varchar)+':30:00' end) as DateTime)) END),
ID,Code
Order by Interval
Actual table data.
DateTime ID Code Duration
2017-12-12 00:30:00 1 12 1800
2017-12-12 00:30:37 1 12 37
2017-12-12 01:00:00 1 12 1793
2017-12-12 01:30:00 1 12 1800
2017-12-12 01:30:59 1 12 59
If I run the query then expected result is,
DateTime ID Code Duration
2017-12-12 00:00:00 1 12 1837
2017-12-12 00:30:00 1 12 1800
2017-12-12 01:00:00 1 12 1800
2017-12-12 01:30:00 1 12 59
DateTime ID Code Duration
2017-12-12 00:00:00 1 12 1800
2017-12-12 00:30:00 1 12 1800
2017-12-12 01:00:00 1 12 1800
2017-12-12 01:30:00 1 12 59

Answer 1

You can use date functions to round [DateTime] into 30 minute intervals, but the result does not match your expected result, which appears to be wrong
DateTime ID Code Duration
2017-12-12 00:30:00 1 12 1800 1800 + 337 = 1837 2017-12-12 00:30
2017-12-12 00:30:37 1 12 37
2017-12-12 01:00:00 1 12 1793 1793 2017-12-12 01:00
2017-12-12 01:30:00 1 12 1800 1800 + 59 = 1859 2017-12-12 01:30
2017-12-12 01:30:59 1 12 59
SQL Fiddle
MS SQL Server 2014 Schema Setup:
CREATE TABLE Table1
([DateTime] datetime, [ID] int, [Code] int, [Duration] int)
;
INSERT INTO Table1
([DateTime], [ID], [Code], [Duration])
VALUES
('2017-12-12 00:30:00', 1, 12, 1800),
('2017-12-12 00:30:37', 1, 12, 37),
('2017-12-12 01:00:00', 1, 12, 1793),
('2017-12-12 01:30:00', 1, 12, 1800),
('2017-12-12 01:30:59', 1, 12, 59)
;
Query 1:
select
dateadd(minute, (datediff(minute, [DateTime], 0) / 30) * 30, 0)
, sum(duration)
from table1
group by
dateadd(minute, (datediff(minute, [DateTime], 0) / 30) * 30, 0)
Results:
| | |
|----------------------|------|
| 1782-01-19T22:30:00Z | 1859 |
| 1782-01-19T23:00:00Z | 1793 |
| 1782-01-19T23:30:00Z | 1837 |