解答
209
SQL文(クエリ)
WITH master AS ( SELECT FORMAT_DATETIME("%Y", date_time) AS year , FORMAT_DATETIME("%B", date_time) AS month , SUM(revenue) AS sum_rev FROM sample.sales WHERE FORMAT_DATETIME("%Y", date_time) IN("2017", "2018") GROUP BY year , month ) SELECT month , MAX(sum_rev_2017) AS sum_rev_2017 , MAX(sum_rev_2018) AS sum_rev_2018 , ROUND(MAX(sum_rev_2018) / MAX(sum_rev_2017), 2) AS change FROM ( SELECT month , IF(year = "2017", sum_rev, 0) AS sum_rev_2017 , IF(year = "2018", sum_rev, 0) AS sum_rev_2018 FROM master ) GROUP BY month ORDER BY 4 DESC LIMIT 3