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

虽然勉强通过
看了大佬们的写的代码，我发现我写的十分的笨拙，竟然想不到用case 或者 if函数！！！ 我恨！！