Let\'s say I have a table:
SELECT SUM(quantity) AS items_sold_since_date, product_ID FROM Sales WHERE order_date >= \'01/01/09\' GROUP BY product_
something like this?:
SELECT SUM(quantity) AS items_sold_since_date, total_items_sold = (SELECT SUM(quantity) from Sales GROUP BY product_ID), product_ID FROM Sales WHERE order_date >= '01/01/09' GROUP BY product_ID