题解 | #重点@when+分组：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 is null then '未填写'
when age > 50 then '50以上'
when age >= 20 and age<=50 then '20-50'
else '20以下'
end
) as age_group,
count(*) as user_count
from
customers_info
group by
age_group
投递新东方等公司10个岗位