Something like this?
SELECT DISTINCT
CustId
FROM
(
SELECT
CustId
FROM
product_details
WHERE
ProdId = 1
AND CustId IN (SELECT DISTINCT CustId FROM product_details WHERE ProdId = 4)
EXCEPT
SELECT CustId
FROM
product_details
WHERE
ProdId = 0
) AS A
Andy
==========================================================================================================================
A computer lets you make more mistakes faster than any invention in human history - with the possible exceptions of handguns and tequila. Mitch Ratcliffe