Execute this Spit function in you DB:
create FUNCTION [dbo].[Split]
(
@String NVARCHAR(4000),
@Delimiter NCHAR(1)
)
RETURNS TABLE
AS
RETURN
(
WITH Split(stpos,endpos)
AS(
SELECT 0 AS stpos, CHARINDEX(@Delimiter,@String) AS endpos
UNION ALL
SELECT endpos+1, CHARINDEX(@Delimiter,@String,endpos+1)
FROM Split
WHERE endpos > 0
)
SELECT 'Id' = ROW_NUMBER() OVER (ORDER BY (SELECT 1)),
'Data' = SUBSTRING(@String,stpos,COALESCE(NULLIF(endpos,0),LEN(@String)+1)-stpos)
FROM Split
)
and Alter your Sp like this,
alter PROCEDURE sp_fuelmargin @storeid varchar(50),@fromdate datetime,@todate datetime
AS
select storeid,businessDate,fuelGrade,fuelGradeDesc,SUM(sales) as Sales,sum(Volume)as Volume from FuelSaleSummary where storeid in (select data from dbo.split(@storeid,',')) and businessDate between @fromdate and @todate
group by StoreId,businessDate,fuelGrade,fuelGradeDesc
order by StoreId
GO
now exec your Sp:
EXEC sp_fuelmargin 'tx001-strb,TX000-IFFI','2014-01-01','2014-05-30'