题解 | #计算25岁以上和以下的用户数量#
计算25岁以上和以下的用户数量
https://www.nowcoder.com/practice/30f9f470390a4a8a8dd3b8e1f8c7a9fa
select '25岁以下' as age_cut,count(device_id) from user_profile where age <25 or age is null union (select '25岁及以上' as age_cut,count(device_id) from user_profile where age >=25)