Generate 15 minute date intervals and join matching rows - sql

Question

What I would like to do is get the 15 minute intervals based on a date range in a row and insert them into another table.
Given the following code gets me the date range which is part of my goal:
DECLARE #Table1 TABLE (ID INT IDENTITY(0,1), TIMEVALUE DATETIME, TIMEVALUE2 DATETIME);
DECLARE #start DATETIME2(7) = '2018-01-04 10:55:00'
DECLARE #end DATETIME2(7) = '2018-01-05 03:55:00'
SELECT #start = dateadd(minute, datediff(minute,0,#start) / 15 * 15, 0);
WITH CTE_DT AS
(
SELECT #start AS DT
UNION ALL
SELECT DATEADD(MINUTE,15,DT) FROM CTE_DT
WHERE DT< #end
)
INSERT INTO #Table1
SELECT DT, DATEADD(minute,14,dt) FROM CTE_DT
OPTION (MAXRECURSION 0);
SELECT * FROM #Table1
result:
ID TIMEVALUE TIMEVALUE2
0 2018-01-04 10:45:00.000 2018-01-04 10:59:00.000
1 2018-01-04 11:00:00.000 2018-01-04 11:14:00.000
2 2018-01-04 11:15:00.000 2018-01-04 11:29:00.000
3 2018-01-04 11:30:00.000 2018-01-04 11:44:00.000
4 2018-01-04 11:45:00.000 2018-01-04 11:59:00.000
5 2018-01-04 12:00:00.000 2018-01-04 12:14:00.000
6 2018-01-04 12:15:00.000 2018-01-04 12:29:00.000
7 2018-01-04 12:30:00.000 2018-01-04 12:44:00.000
8 2018-01-04 12:45:00.000 2018-01-04 12:59:00.000
..
..
What I want to accomplish is the apply the same logic above i from a record source.
So if my SourceData is
Col1 Col2 StartDate EndDate
AA AA 2018-01-01 13:25 2018-01-02 13:00
AA BB 2018-01-02 13:25 2018-01-03 13:00
so with a query somehow use the start and endate to produce this result with just a query
Col1 Col2 TIMEVALUE TIMEVALUE2
AA AA 2018-01-01 13:15:00 2018-01-01 13:29:00
AA AA 2018-01-01 13:30:00 2018-01-01 13:44:00
AA AA 2018-01-01 13:45:00 2018-01-01 13:59:00
...
...
AA AA 2018-01-02 12:30:00 2018-01-02 12:44:00
AA AA 2018-01-02 12:45:00 2018-01-02 12:59:00
AA AA 2018-01-02 13:00:00 2018-01-02 13:14:00
AA BB 2018-01-02 13:15:00 2018-01-02 13:29:00
AA BB 2018-01-02 13:30:00 2018-01-02 13:44:00
AA BB 2018-01-02 13:45:00 2018-01-02 13:59:00
...
...
AA BB 2018-01-03 12:30:00 2018-01-03 12:44:00
AA BB 2018-01-03 12:45:00 2018-01-03 12:59:00
AA BB 2018-01-03 13:00:00 2018-01-03 13:14:00
I would like to avoid using a cursor if I can. I have managed to make this work with a User Defined Function by passing the required columns with the select statement. I am hoping I can avoid using that if I can.

Answer 1

Change the end of the first query so that instead of
SELECT * FROM #Table1
It says:
SELECT * FROM #Table1 d
INNER JOIN SourceData sd
ON NOT(d.timevalue2 < sd.startdate OR d.timevalue1 > sd.enddate)
Consider taking your first query that generates the dates, and just run it for now until year 2030 and insert the dates into an actual table. Keep the query hanging around so it can be used again in ~11 years to add some more rows to the calendar table

Answer 2

Rather than using a rCTE (which is a form of RBAR), I would use a virtual tally table to generate your dates:
--; is a statement terminator, not a "beginninator". It goes at the end, for the start.
WITH N AS(
SELECT NULL AS N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL)) N(N)),
Tally AS (
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1 AS I
FROM N N1 --10
CROSS JOIN N N2 --100
CROSS JOIN N N3 --1000
CROSS JOIN N N4 --10000
)
SELECT DATEADD(MINUTE,15*I,#Start)
FROM Tally
WHERE DATEADD(MINUTE,15*I,#Start) < #End;
If you want to generate 15 minute intervals for a combination of columns, you can then do a further CROSS JOIN. For example:
--Assume CTEs are already declared
SELECT V.Col1, V.Col2,
DATEADD(MINUTE,15*T.I,#Start)
FROM Tally T
CROSS JOIN (VALUES('AA','AA'),('AA','BB')) V(Col1, Col2) --This could be a CROSS APPLY to a DISTINCT, or similar is you wish
WHERE DATEADD(MINUTE,15*T.I,#Start) < #End;