题解 | #分群并计算群体人数#
分群并计算群体人数
https://www.nowcoder.com/practice/24319fd5c03e482c935783107114933d
SELECT ( CASE WHEN age < 20 THEN '20以下' WHEN age >= 20 AND age <= 50 THEN '20-50' WHEN age > 50 THEN '50以上' ELSE '未填写' END ) AS age_group, count(customer_id) AS user_count FROM customers_info GROUP BY age_group