解答
200
SQL文(クエリ)
WITH master AS ( SELECT product_id , SUM(quantity) AS sum_qty , SUM(revenue) AS sum_rev FROM sample.sales GROUP BY product_id ) SELECT * , unit_cost * sum_qty AS sum_cost , (avg_rev - unit_cost) * sum_qty AS sum_profit , ((avg_rev - unit_cost) * sum_qty) / sum_rev AS avg_profit_rate FROM ( SELECT product_name , sum_rev / sum_qty AS avg_rev , cost AS unit_cost , sum_qty , sum_rev FROM master JOIN sample.products USING (product_id) ) ORDER BY 8 DESC LIMIT 3