SELECT
    SUM(total)
FROM
    (SELECT
       DISTINCT (order_id), total_item_count AS total
    FROM
        zzz_sales
    WHERE
        ((created_at BETWEEN '2011-12-01 05:00:00' AND '2012-01-01 04:59:59') AND (STATUS IN ('processing','complete'))) AND (product_type IN ('simple','giftcard'))) AS t;



SELECT SUM(qty_ordered) FROM `zzz_sales` WHERE ((created_at BETWEEN '2011-12-01 05:00:00' AND '2012-01-01 04:59:59') AND (STATUS IN ('processing', 'complete'))) AND (product_type IN ('simple', 'giftcard'));