How to break datetime in 15 minute interval in sql sever 2014 - sql

Question

I have split the below query in 15 minute interval on the basis of Start datetime but this query is not providing the exact result set
as i am expecting.
Below is the example of query i want to execute.
select Date_Stamp,
Case when substring(convert(char(8),starttime,114), 1, 8) between '12:00:01 AM'and '12:15:00 AM' then '0015'
when substring(convert(char(8),starttime,114), 1, 8) between '12:15:01 AM'and '12:30:00 AM' then '0030'
when substring(convert(char(8),starttime,114), 1, 8) between '12:30:01 AM'and '12:45:00 AM' then '0045'
when substring(convert(char(8),starttime,114), 1, 8) between '12:45:01 AM'and '01:00:00 AM' then '0100'
and i want the result as
Date Need result set
12:01 AM '0015'
'12:15:01 '0030'
'12:30:01 '0045'
'12:45:01 '0100'
'01:00:01 '0115'
'01:15:01 '0130'
'01:30:01 '0145'
'01:45:01 '0200'
'02:00:01 '0215'
'02:15:01 '0230'
'02:30:01 '0245'
3:00:00 ' '0015'
'12:30:00 '0030'
'12:45:00 '0045'
'01:00:00 '0100'
'01:15:00 '0115'
'01:30:00 '0130'
'01:45:00 '0145'
'02:00:00 '0200'
'02:15:00 '0215'
'02:30:00 '0230'
'02:45:00 '0245'

Answer 1

Just change #starttime with your column name
DECLARE #starttime datetime = getdate()
SELECT CONCAT(CASE WHEN DATEPART(HH, #starttime) <= 9
THEN '00'+ CAST(DATEPART(HH, #starttime) AS VARCHAR(2))
ELSE '0'+CAST(DATEPART(HH, #STARTTIME) AS VARCHAR(2))
END,
CASE WHEN DATEPART(MINUTE, #STARTTIME) BETWEEN 1 AND 15
THEN 15
WHEN DATEPART(MINUTE, #STARTTIME) BETWEEN 16 AND 30
THEN 30
WHEN DATEPART(MINUTE, #STARTTIME) BETWEEN 31 AND 45
THEN 45
WHEN DATEPART(MINUTE, #STARTTIME) BETWEEN 46 AND 59 OR DATEPART(MINUTE, #STARTTIME) = 0
THEN 00
END)

Answer 2

You can use this date generator:
DEMO
DECLARE #Break INT = 15
;WITH Numbers (n) as
(
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL))-1
FROM (VALUES (0),(0),(0),(0),(0),(0),(0),(0)) a(n)
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) b(n)
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) c(n)
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) d(n)
)
,Dates as
(
SELECT dt
FROM Numbers
CROSS APPLY
(
VALUES (DATEADD(MINUTE , n, CAST(CAST(GETDATE() AS DATE) AS DATETIME)))
) X(Dt)
WHERE N % #Break = 0
AND CAST(DT AS DATE) = CAST(GETDATE() AS DATE) --Only for today's date
)
SELECT CONVERT(VARCHAR(10),Dt,108) [Time] , REPLACE(CONVERT(VARCHAR(5),ISNULL(Lead(Dt) OVER (ORDER BY Dt) , DATEADD(MINUTE,#Break,Dt)),108), ':','') Grp
FROM Dates

Answer 3

It appears you're using datetime and have only taken the substring of the time. A string cannot be compared to a time, without being casted to the time datatype.
For example:
DECLARE #mytable TABLE (starttime datetime)
INSERT INTO #mytable VALUES ('2018-03-13 00:00:01'), ('2018-03-15 00:00:01')
SELECT * FROM #mytable
select CAST(starttime as time(0)) AS [thetime],
Case when CAST(starttime as time) between '12:00:01 AM'and '12:15:00 AM' then '0015'
when CAST(starttime as time) between '12:15:01 AM'and '12:30:00 AM' then '0030'
when CAST(starttime as time) between '12:30:01 AM'and '12:45:00 AM' then '0045'
when CAST(starttime as time) between '12:45:01 AM'and '01:00:00 AM' then '0100'
END AS [Interval]
FROM #mytable
Produces:
thetime Interval
00:00:01 0015
00:15:01 0030