Return value from function in SQL Server - sql-server

Question

I want to get the last Saturday from today + 21 days.
In order to achieve this, I have written this script shown below. But the problem is that I can't get success to return the value from the result.
I want to create this function in SQL Server and will get this value in a stored procedure where I want.
DECLARE #StartDate DATETIME
DECLARE #EndDate DATETIME
DECLARE #NumOfDays INT
DECLARE #resultDate smalldatetime
SET #StartDate = GETDATE()
SET #EndDate = GETDATE()+21
SET #NumOfDays = DATEDIFF(DD,#StartDate , #EndDate) + 1 ;
WITH Tens AS
(
SELECT 1 N UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1
),
HUNDREDS AS
(
SELECT T1.N FROM TENS T1 CROSS JOIN TENS T2
),
THOUSANDS AS
(
SELECT T1.N FROM HUNDREDS T1 CROSS JOIN HUNDREDS T2
),
Numbers AS
(
SELECT ROW_NUMBER() OVER(ORDER BY (SELECT 0)) RN FROM THOUSANDS
)
SELECT TOP 1
DATEADD(DD, (RN - 1), #StartDate) SaturdayDates
FROM
Numbers
WHERE
RN <= #NumOfDays
AND DATENAME (WEEKDAY, (DATEADD(DD, (RN - 1), #StartDate))) = 'Saturday'
ORDER BY
SaturdayDates DESC
Can you please guide me to achieve my goal? Thanks

Answer 1

Just rewrite it like this table-valued function:
CREATE FUNCTION dbo.Get_NextSaturdayDay()
RETURNS TABLE
AS
RETURN
(
-- Add the SELECT statement with parameter references here
WITH Tens AS
(
SELECT 1 N UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1
),
HUNDREDS AS
(
SELECT T1.N FROM TENS T1 CROSS JOIN TENS T2
),
THOUSANDS AS
(
SELECT T1.N FROM HUNDREDS T1 CROSS JOIN HUNDREDS T2
),
Numbers AS
(
SELECT ROW_NUMBER() OVER(ORDER BY (SELECT 0)) RN FROM THOUSANDS
)
SELECT TOP 1 DATEADD( DD,(RN - 1) , GETDATE() ) as SaturdayDates
FROM
Numbers
WHERE
RN <= (DATEDIFF(DD,GETDATE() , DATEADD(day,21,GETDATE()) ) + 1) AND DATENAME ( WEEKDAY, (DATEADD( DD,(RN - 1) , GETDATE() )) ) = 'Saturday'
ORDER BY SaturdayDates DESC
)
GO
Than do:
SELECT *
FROM dbo.Get_NextSaturdayDay()
Output:
SaturdayDates
2016-10-15 11:02:33.570
If you need scalar-valued function:
CREATE FUNCTION dbo.Get_NextSaturdayDay ()
RETURNS datetime
AS
BEGIN
DECLARE #datetime datetime
;WITH Tens AS
(
SELECT 1 N UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1 UNION ALL
SELECT 1
),
HUNDREDS AS
(
SELECT T1.N FROM TENS T1 CROSS JOIN TENS T2
),
THOUSANDS AS
(
SELECT T1.N FROM HUNDREDS T1 CROSS JOIN HUNDREDS T2
),
Numbers AS
(
SELECT ROW_NUMBER() OVER(ORDER BY (SELECT 0)) RN FROM THOUSANDS
)
SELECT TOP 1 #datetime = DATEADD( DD,(RN - 1) , GETDATE() )
FROM
Numbers
WHERE
RN <= (DATEDIFF(DD,GETDATE() , DATEADD(day,21,GETDATE()) ) + 1) AND DATENAME ( WEEKDAY, (DATEADD( DD,(RN - 1) , GETDATE() )) ) = 'Saturday'
ORDER BY DATEADD( DD,(RN - 1) , GETDATE() ) DESC
-- Return the result of the function
RETURN #datetime
END
GO
Then run:
SELECT dbo.Get_NextSaturdayDay()
Output:
2016-10-15 11:02:33.570