How to generate minute intervals between two dates in T-SQL? - sql-server

Question

I have a table of startTime and endTimes. I need to generate a table of intervals between those two dates in minutes. Here's some sample data:
declare #intervalMinutes int = 10
declare #myDates table (
myId int primary key identity,
startTime datetime,
endTime datetime
)
insert #myDates (startTime, EndTime) values ('2016-07-10 08:00','2016-07-10 09:00')
insert #myDates (startTime, EndTime) values ('2016-07-12 10:00','2016-07-12 12:00')
insert #myDates (startTime, EndTime) values ('2016-07-14 12:30','2016-07-14 14:30')
What I'd like to see is for each myId a set of dates of interval #intervalMinutes.
So if we had #intervalMinutes set to 10 then I'd see for the first row a list of 6 dates between 2016-07-10 08:00 and 2016-07-10 09:00 in 10 minute increments.

Answer 1

You can use recursive query like this :
declare #intervalMinutes int = 10
declare #myDates table (
myId int primary key identity,
startTime datetime,
endTime datetime
)
DECLARE #startTime DATETIME = '2016-07-10 08:00'
DECLARE #endTime DATETIME = '2016-07-10 09:00'
;WITH CTE AS
(
SELECT #startTime st
UNION ALL
SELECT dateadd(MINUTE,#intervalMinutes,st) st
FROM cte
where dateadd(MINUTE,#intervalMinutes,st) < #endTime
)
INSERT INTO #myDates(startTime,endTime)
SELECT st,dateadd(MINUTE,#intervalMinutes,st) FROM cte
SELECT * FROm #myDates

Answer 2

A numbers/tally table would do the trick as Gordon mentioned. However, I use a UDF to create dynamic date ranges.
For example
Select * from [dbo].[udf-Create-Range-Date]('2016-07-10 08:00','2016-07-10 09:00','MI',10)
Returns
RetVal
2016-07-10 08:00:00.000
2016-07-10 08:10:00.000
2016-07-10 08:20:00.000
2016-07-10 08:30:00.000
2016-07-10 08:40:00.000
2016-07-10 08:50:00.000
2016-07-10 09:00:00.000
The UDF
CREATE FUNCTION [dbo].[udf-Create-Range-Date] (#DateFrom datetime,#DateTo datetime,#DatePart varchar(10),#Incr int)
Returns
#ReturnVal Table (RetVal datetime)
As
Begin
With DateTable As (
Select DateFrom = #DateFrom
Union All
Select Case #DatePart
When 'YY' then DateAdd(YY, #Incr, df.dateFrom)
When 'QQ' then DateAdd(QQ, #Incr, df.dateFrom)
When 'MM' then DateAdd(MM, #Incr, df.dateFrom)
When 'WK' then DateAdd(WK, #Incr, df.dateFrom)
When 'DD' then DateAdd(DD, #Incr, df.dateFrom)
When 'HH' then DateAdd(HH, #Incr, df.dateFrom)
When 'MI' then DateAdd(MI, #Incr, df.dateFrom)
When 'SS' then DateAdd(SS, #Incr, df.dateFrom)
End
From DateTable DF
Where DF.DateFrom < #DateTo
)
Insert into #ReturnVal(RetVal) Select DateFrom From DateTable option (maxrecursion 32767)
Return
End
-- Syntax Select * from [dbo].[udf-Create-Range-Date]('2016-10-01','2020-10-01','YY',1)
-- Syntax Select * from [dbo].[udf-Create-Range-Date]('2016-10-01','2020-10-01','DD',1)
-- Syntax Select * from [dbo].[udf-Create-Range-Date]('2016-10-01','2016-10-31','MI',15)
-- Syntax Select * from [dbo].[udf-Create-Range-Date]('2016-10-01','2016-10-02','SS',1)

Answer 3

A numbers table can solve your problem. Assuming you don't need more than a few thousand rows, then this should work:
with n as (
select row_number() over (order by (select null)) - 1 as n
from master.spt_values
)
select d.*,
dateadd(minute, n.n * #intervalMinutes, d.startTime)
from #myDates d join
n
on dateadd(minute, n.n * #intervalMinutes, d.startTime) <= d.endTime;

Answer 4

To add to #GordonLinoff 's good answer, Jonathan Roberts (from SQLServerCentral.com - See the link in the revision history in the code for the original article) wrote a dandy function that'll handle pretty much anything. The flower box pretty much explains it all along with some example usage Here's his code from his article.
/**********************************************************************************************************************
FUNCTION: DateRange
Returns a table of datetime values based on the parameters
Parameters:
#StartDate :Start date of the series
#EndDate :End date of the series
#DatePart :The time unit for #interval
ns : nanoseconds
mcs : microseconds
ms : milliseconds
ss : seconds
mi : minutes
hh : hours
dd : days
ww : weeks
mm : months
qq : quarters
yy : years
#Interval :The number of dateparts between each value returned
Sample Calls:
SELECT * FROM [dbo].[DateRange]('2011-01-01 12:24:35', '2011-02-01 12:24:35', 'ss', 2);
SELECT COUNT(*) FROM [dbo].[DateRange]('2018-01-01 00:00:00', '2018-01-25 20:31:23.646', 'ms', default);
SELECT * FROM [dbo].[DateRange]('2011-01-01', '2012-02-03', default, default);
SELECT * FROM [dbo].[DateRange]('2012-02-03', '2011-01-01', 'dd', 7);
SELECT DATEDIFF(ns,'2018-01-01 00:00:00.000', value),Value,*
FROM [dbo].[DateRange]('2018-01-01 00:00:00.000', '2018-01-01 00:00:00.00001', 'ns', 100);
-----------------------------------------------------------------------------------------------------------------------
Revision History:
Rev 00 - 29 Aug 2019 - Jonathan Roberts
- Initial release
- Ref: https://www.sqlservercentral.com/scripts/a-daterange-table-valued-function
**********************************************************************************************************************/
CREATE FUNCTION [dbo].[DateRange]
(
#StartDate datetime2,
#EndDate datetime2,
#DatePart nvarchar(3)='dd',
#Interval int=1
)
RETURNS TABLE AS RETURN
WITH A(A) AS (SELECT 0 FROM (VALUES (0),(0),(0),(0),(0),(0),(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) A(A)),
B(RowNum) AS (SELECT TOP(ABS(CASE #DatePart
WHEN 'ns' THEN DATEDIFF(ns, #EndDate, #StartDate)/#Interval
WHEN 'mcs' THEN DATEDIFF(mcs,#EndDate, #StartDate)/#Interval
WHEN 'ms' THEN DATEDIFF(ms, #EndDate, #StartDate)/#Interval
WHEN 'ss' THEN DATEDIFF(ss, #EndDate, #StartDate)/#Interval
WHEN 'mi' THEN DATEDIFF(mi, #EndDate, #StartDate)/#Interval
WHEN 'hh' THEN DATEDIFF(hh, #EndDate, #StartDate)/#Interval
WHEN 'dd' THEN DATEDIFF(dd, #EndDate, #StartDate)/#Interval
WHEN 'ww' THEN DATEDIFF(ww, #EndDate, #StartDate)/#Interval
WHEN 'mm' THEN DATEDIFF(mm, #EndDate, #StartDate)/#Interval
WHEN 'qq' THEN DATEDIFF(qq, #EndDate, #StartDate)/#Interval
WHEN 'yy' THEN DATEDIFF(yy, #EndDate, #StartDate)/#Interval
ELSE DATEDIFF(dd, IIF(#StartDate < #EndDate, #StartDate, #EndDate), IIF(#StartDate < #EndDate, #EndDate, #StartDate))/#Interval
END) + 1)
ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) - 1
FROM A A, A B, A C, A D, A E, A F, A G, A H) -- A maximum of 16^8 (or 2^32) rows could be returned from this inline tally
SELECT CASE #DatePart
WHEN 'ns' THEN DATEADD(ns, T.AddAmount, #StartDate)
WHEN 'mcs' THEN DATEADD(mcs,T.AddAmount, #StartDate)
WHEN 'ms' THEN DATEADD(ms, T.AddAmount, #StartDate)
WHEN 'ss' THEN DATEADD(ss, T.AddAmount, #StartDate)
WHEN 'mi' THEN DATEADD(mi, T.AddAmount, #StartDate)
WHEN 'hh' THEN DATEADD(hh, T.AddAmount, #StartDate)
WHEN 'dd' THEN DATEADD(dd, T.AddAmount, #StartDate)
WHEN 'ww' THEN DATEADD(ww, T.AddAmount, #StartDate)
WHEN 'mm' THEN DATEADD(mm, T.AddAmount, #StartDate)
WHEN 'qq' THEN DATEADD(qq, T.AddAmount, #StartDate)
WHEN 'yy' THEN DATEADD(yy, T.AddAmount, #StartDate)
ELSE DATEADD(dd, T.AddAmount, #StartDate)
END [Value]
FROM B
CROSS APPLY(VALUES (IIF(#StartDate<#EndDate, #interval*RowNum, #interval*-RowNum))) T(AddAmount)
GO