解答
190
SQL文(クエリ)
WITH master AS ( SELECT order_id , quantity , revenue / quantity AS unit_revenue , cost FROM sample.sales JOIN sample.products USING (product_id) ) SELECT order_id , SUM(profit) AS profit_by_order FROM ( SELECT order_id , quantity , (unit_revenue - cost) * quantity AS profit FROM master ) GROUP BY order_id ORDER BY 2 DESC LIMIT 1