SELECT temp2.customer_id, it_temp2.product_id, temp2.order_date
FROM SALES_ORDER temp2, ITEM it_temp2
WHERE (
    SELECT COUNT(temp.order_id)
    FROM SALES_ORDER temp, ITEM it_temp
    WHERE temp.customer_id = temp2.customer_id
    AND ABS(DATEDIFF(DAY, temp.order_date, temp2.order_date)) <= 7
    AND temp.order_id != temp2.order_id
    AND it_temp.order_id = temp.order_id
    AND it_temp.product_id = it_temp2.product_id
    ) > 0
AND it_temp2.order_id = temp2.order_id