解答
189
SQL文(クエリ)
WITH master AS ( SELECT user_id , SUM(revenue) AS sr FROM sample.sales GROUP BY user_id ) SELECT gender_name , ROUND(STDDEV_POP(sr), 0) AS std_dev FROM ( SELECT CASE gender WHEN 1 THEN "男性" WHEN 2 THEN "女性" ELSE NULL END AS gender_name , sr FROM master LEFT JOIN sample.customers USING (user_id) ) GROUP BY gender_name