解答
143
SQL文(クエリ)
WITH master AS (
SELECT
user_id
, SUM(revenue) AS sum_rev
FROM
sample.sales
GROUP BY
user_id
)
SELECT
IF(is_premium IS TRUE, "premium_users", "standard_users") AS user_category
, MAX(sum_rev) AS max_revenue_by_customer
FROM
master
JOIN sample.customers
USING
(user_id)
GROUP BY
user_category



