SELECT p.`product_name` AS 'Название товара', o.`product_id` AS 'ID Товара', ROUND( p.`in_price` ) AS 'Входящая цена', ROUND( o.`price` ) AS 'Цена продажи', ROUND( SUM( o.`price` ) ) AS 'Сумма', COUNT( o.`product_id` ) AS 'Количество'
FROM (

SELECT *
FROM `orders`
WHERE `parent_id`
IN (

SELECT `id`
FROM `orders`
WHERE `status` = 'доставлен'
)
)o, `products` p
WHERE p.`product_id` = o.`product_id`
AND p.`developer` =42
GROUP BY o.`product_id`
ORDER BY COUNT( o.`product_id` ) DESC