SQL Server time interval to multiple rows - sql-server

Question

I have this record with StartDateTime and EndDateTime and I want the result to be in rows with 15 minutes interval:
Sample data:
FName | StartDateTime | EndDateTime
:----- | -----------: | :--------------:
Juan | 08/01/2017 1:00| 08/01/2017 8:00
Result:
FName | Interval
:----- | -----------:
Juan | 08/01/2017 1:00
Juan | 08/01/2017 1:15
Juan | 08/01/2017 1:30
Juan | 08/01/2017 1:45
Juan | 08/01/2017 2:00
Until it reaches to its EndDateTime, how can I achieve this in SQL. I'm thinking using looping statement or cte.

Answer 1

If you are open to a TVF (Table-Valued Function)
I'll often use this udf to create dynamic date/time ranges. It is faster than a recursive CTE and parameter driven.
The parameters are Date1, Date2, DatePart, and Increment
Example
Declare #YourTable Table ([FName] varchar(50),[StartDateTime] datetime,[EndDateTime] datetime)
Insert Into #YourTable Values
('Juan','08/01/2017 1:00','08/01/2017 8:00')
Select A.FName
,B.*
From #YourTable A
Cross Apply [dbo].[udf-Range-Date](A.StartDateTime,A.EndDateTime,'MI',15) B
Returns
FName RetSeq RetVal
Juan 1 2017-08-01 01:00:00.000
Juan 2 2017-08-01 01:15:00.000
Juan 3 2017-08-01 01:30:00.000
Juan 4 2017-08-01 01:45:00.000
Juan 5 2017-08-01 02:00:00.000
...
Juan 29 2017-08-01 08:00:00.000
The UDF if Interested
CREATE FUNCTION [dbo].[udf-Range-Date] (#R1 datetime,#R2 datetime,#Part varchar(10),#Incr int)
Returns Table
Return (
with cte0(M) As (Select 1+Case #Part When 'YY' then DateDiff(YY,#R1,#R2)/#Incr When 'QQ' then DateDiff(QQ,#R1,#R2)/#Incr When 'MM' then DateDiff(MM,#R1,#R2)/#Incr When 'WK' then DateDiff(WK,#R1,#R2)/#Incr When 'DD' then DateDiff(DD,#R1,#R2)/#Incr When 'HH' then DateDiff(HH,#R1,#R2)/#Incr When 'MI' then DateDiff(MI,#R1,#R2)/#Incr When 'SS' then DateDiff(SS,#R1,#R2)/#Incr End),
cte1(N) As (Select 1 From (Values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N(N)),
cte2(N) As (Select Top (Select M from cte0) Row_Number() over (Order By (Select NULL)) From cte1 a, cte1 b, cte1 c, cte1 d, cte1 e, cte1 f, cte1 g, cte1 h ),
cte3(N,D) As (Select 0,#R1 Union All Select N,Case #Part When 'YY' then DateAdd(YY, N*#Incr, #R1) When 'QQ' then DateAdd(QQ, N*#Incr, #R1) When 'MM' then DateAdd(MM, N*#Incr, #R1) When 'WK' then DateAdd(WK, N*#Incr, #R1) When 'DD' then DateAdd(DD, N*#Incr, #R1) When 'HH' then DateAdd(HH, N*#Incr, #R1) When 'MI' then DateAdd(MI, N*#Incr, #R1) When 'SS' then DateAdd(SS, N*#Incr, #R1) End From cte2 )
Select RetSeq = N+1
,RetVal = D
From cte3,cte0
Where D<=#R2
)
/*
Max 100 million observations -- Date Parts YY QQ MM WK DD HH MI SS
Syntax:
Select * from [dbo].[udf-Range-Date]('2016-10-01','2020-10-01','YY',1)
Select * from [dbo].[udf-Range-Date]('2016-01-01','2017-01-01','MM',1)
*/

Answer 2

You could use a recursive query like this
DECLARE #SampleData AS TABLE
(
FName varchar(20),
StartDatetime datetime,
EndDatetime datetime
)
INSERT INTO #SampleData
(
FName,
StartDatetime,
EndDatetime
)
VALUES
('Juan', '2017-08-01 1:00', '2017-08-01 8:00')
;WITH temp AS
(
SELECT sd.FName, sd.StartDatetime AS Interval, sd.EndDatetime
FROM #SampleData sd
UNION ALL
SELECT t.FName, dateadd(minute, 15, t.Interval) AS Interval, t.EndDatetime
FROM temp t
WHERE dateadd(minute, 15, t.Interval) <= t.EndDatetime
)
SELECT t.FName,
t.Interval
FROM temp t
OPTION (MAXRECURSION 0)
Demo link: http://rextester.com/CELP88345

Answer 3

It is better to use date table but you can generate as below:
Select Fname, RowN as Interval from #dates
cross apply (
Select top(datediff(hh,startdatetime, enddatetime)*4+1) RowN =dateadd(mi, (row_number() over(order by (Select NULL)) -1)*15 ,startdatetime)
from master..spt_values s1, master..spt_values s2 ) a
Output as below:
+-------+-------------------------+
| Fname | Interval |
+-------+-------------------------+
| Juan | 2017-08-01 01:00:00.000 |
| Juan | 2017-08-01 01:15:00.000 |
| Juan | 2017-08-01 01:30:00.000 |
| Juan | 2017-08-01 01:45:00.000 |
| Juan | 2017-08-01 02:00:00.000 |
| Juan | 2017-08-01 02:15:00.000 |
| Juan | 2017-08-01 02:30:00.000 |
| Juan | 2017-08-01 02:45:00.000 |
| Juan | 2017-08-01 03:00:00.000 |
| Juan | 2017-08-01 03:15:00.000 |
| Juan | 2017-08-01 03:30:00.000 |
| Juan | 2017-08-01 03:45:00.000 |
| Juan | 2017-08-01 04:00:00.000 |
| Juan | 2017-08-01 04:15:00.000 |
| Juan | 2017-08-01 04:30:00.000 |
| Juan | 2017-08-01 04:45:00.000 |
| Juan | 2017-08-01 05:00:00.000 |
| Juan | 2017-08-01 05:15:00.000 |
| Juan | 2017-08-01 05:30:00.000 |
| Juan | 2017-08-01 05:45:00.000 |
| Juan | 2017-08-01 06:00:00.000 |
| Juan | 2017-08-01 06:15:00.000 |
| Juan | 2017-08-01 06:30:00.000 |
| Juan | 2017-08-01 06:45:00.000 |
| Juan | 2017-08-01 07:00:00.000 |
| Juan | 2017-08-01 07:15:00.000 |
| Juan | 2017-08-01 07:30:00.000 |
| Juan | 2017-08-01 07:45:00.000 |
| Juan | 2017-08-01 08:00:00.000 |
+-------+-------------------------+

Answer 4

You can use Recursive CTE to achieve the expected results.
Demo - http://sqlfiddle.com/#!6/821a5/11
with cte as
(
select Fname,StartDateTime
from Table1
union all
select Fname,DATEADD(mi,15,StartDateTime) as StartDateTime
from cte
where DATEADD(mi,15,StartDateTime) <= '2017-01-08 08:00:00:000'
)
select Fname, StartDateTime from cte;