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;