JOIN technique

Create Procedure dbo.sp_JoinTechnique

@BrandId_List varchar = ''-- for all brands the list would be empty

AS 
BEGIN
/* Execution sample
exec dbo.sp_JoinTechnique ',2,3,5,6,' 

*/-- Using the function developed by my friend, CVMichael, and me,  the dbo.fn_SplitStringToTable
DECLARE @tbl_Brands TABLE (BrandID INT)

INSERT INTO @tbl_Brands
SELECT ItemData 
FROM dbo.fn_SplitStringToTable (ISNULL(@BrandId_List,''),',') your_Brands

--I can do it like this:

SELECT *
FROM 
Sales s
INNER JOINProducts p on c.customerId = p.customerId
INNER JOINBrands b on p.BrandId = b.BrandId -- do the LEFT JOIN Brands if you have products without brands
LEFT JOIN@tbl_Brands tb on b.brandId = tb.BrandId
WHERE
@BrandId_List = '' 
OR 
tb.BrandId is NOT NULL

--OR I can do it like this (the way I RECOMMEND):

SELECT *
FROM 
Sales s
INNER JOINProducts p on c.customerId = p.customerId
LEFT JOINBrands b 
INNER JOIN@tbl_Brands tb on b.brandId = tb.BrandId
on p.BrandId = b.BrandId
WHERE
@BrandId_List = '' 
OR 
b.BrandId is NOT NULL

--You can use this technique instead of:
/*
...INNER JOINProducts p on c.customerId = p.customerId
LEFT JOIN (SELECT br.* FROM Brands br INNER JOIN@tbl_Brands tb on br.brandId = tb.BrandId) b
on p.BrandId = b.BrandId
*/END