Execute stored procedure with a nullable parameter from SQL server - sql-server

Question

I have a stored procedure, MYTASK1, with several parameters. It gets called something like this:
EXECUTE MYTASK1 '2021' , '1','1'
How do I run the stored procedure if the parameter is null. I tried
EXECUTE MYTASK1 '2021' , '' ,''
but it doesn't do anything.
my stored procedure
ALTER PROC MYTASK1 #Year varchar(6) = NULL,
#quarter varchar(6) = NULL,
#month varchar(6) = NULL
AS
BEGIN
SELECT 'Sell Out' AS name,
'Total Sales Amount' AS Description,
'down' AS status,
CAST(SUM(NetValue) AS decimal(9, 2)) AS amount
FROM SalesAndReturns_RPT
GROUP BY YEAR(Call_ActualStartDate),
DATEPART(QUARTER, Call_ActualStartDate),
MONTH(Call_ActualStartDate)
HAVING YEAR(Call_ActualStartDate) = #Year
AND DATEPART(QUARTER, Call_ActualStartDate) = #quarter
AND MONTH(Call_ActualStartDate) = #month;
END;

Answer 1

This is a guess, but I assume this is what you want:
ALTER PROC dbo.MYTASK1 #Year int = NULL, --Makes no sense as a varchar(6)
#Quarter int = NULL, --Makes no sense as a varchar(6)
#Month int = NULL --Makes no sense as a varchar(6)
AS
BEGIN
SELECT 'Sell Out' AS name,
'Total Sales Amount' AS Description,
'down' AS status,
CAST(SUM(NetValue) AS decimal(9, 2)) AS amount
FROM dbo.SalesAndReturns_RPT
WHERE ((Call_ActualStartDate >= DATEFROMPARTS(#Year, 1, 1) AND Call_ActualStartDate < DATEFROMPARTS(#Year+1, 1, 1)) OR #Year IS NULL)
AND (DATEPART(QUARTER, Call_ActualStartDate) = #Quarter OR #Quarter IS NULL)
AND (DATEPART(MONTH,Call_ActualStartDate) = #Month OR #Month IS NULL)
OPTION (RECOMPILE);
END;
I have made the clause for #Year SARGable, however, with no information about on how #month and #quarter should be handled if #Year is NULL then this will likely make little difference, as those clauses are not SARGable. I have assumed that if #Year is NULL but #Month isn't, you would want the SUM for all rows in that month, regardless of the year it falls in.
If you do want a SARGable solution for this requirement, you'll need to implement a Calendar table.

Answer 2

The code which you are executing: EXECUTE MYTASK1 '2021' , '' ,'' triggers procedure MYTASK1 with empty strings as parameters. Please note that empty string is it a different value than null... NULL is lacks of value, while empty string is totally valid string ;)
You can try
EXECUTE MYTASK1 '2021' , NULL ,NULL
In your case NULL is a defoult value, so you can also use:
EXECUTE MYTASK1 '2021'

Answer 3

Since you have NULL as default, you can just not provide a parameter value at all
EXECUTE MYTASK1 '2021'
is the same as
EXECUTE MYTASK1 '2021', NULL, NULL
You can also use named parameters like so:
EXECUTE MYTASK1 #quarter='Q1'
However, going by other answers and comments, you have substantial issues with the contect of the stored proc.