题解 | #计算25岁以上和以下的用户数量#

select "25岁以下" as age_cut ,
      count(device_id) as number
from user_profile
where age < 25 or age is null

union all

select "25岁及以上" as age_cut ,
      count(device_id) as number
from user_profile
where age>=25