Question

I have the following table: compare. I need to do an inner join with a products table:

idCompare idProduct dateStamp
1         1         2011-12-12
2         1         2011-12-10
3         1         2012-01-05

I want to exclude the idproduct’s from my results if any of them have a date within say 7 days.

I’ve tried using the NOT IN and NOT EXISTS without success

SELECT     products.idProduct
FROM         products INNER JOIN
             compare ON products.idProduct = compare.idProduct
WHERE
(products.idProduct = '1') AND (products.idProduct 
    NOT IN
    (SELECT     idProduct
    FROM          compare
    WHERE      (products.idProduct = compare.idProduct) AND
    (dateStamp < DATEADD(DAY, - 7, GETDATE())))) 

Answer 1

Could look like this:

SELECT p.idProduct
FROM   products AS p
WHERE  NOT EXISTS (
   SELECT *
   FROM   compare AS c
   WHERE  c.idProduct = p.idProduct
   AND    c.dateStamp BETWEEN DATEADD(DAY, - 7, GETDATE()) AND GETDATE()
   )

Don’t JOIN to the table compare in addition. Checking with NOT EXISTS is enough according to your description.