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 between 20 and 50 then '20-50' when age > 50 then '50以上' else '未填写' end as age_group, count(customer_id) user_count from customers_info group by age_group