题解 | #计算25岁以上和以下的用户数量#

还是严格遵守规则好一点

select 
    case 
        when age < 25 or age is null then '25岁以下'
        when age >= 25 then '25岁及以上'
    end as age_cut,
    count(*) as number
from user_profile
group by
    case 
        when age < 25 or age is null then '25岁以下'
        when age >= 25 then '25岁及以上'
    end