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 ;