解答
122
SQL文(クエリ)
SELECT CASE WHEN cost <= 300 THEN "a.300以下" WHEN cost <= 600 THEN "b.301-600" WHEN cost <= 900 THEN "c.601-900" ELSE "d.901以上" END AS cost_category , COUNT(*) AS number_of_products FROM sample.products GROUP BY cost_category ORDER BY 1