题解 | 查看不同年龄段的用户明细

SELECT device_id , gender ,
       (CASE
        WHEN age<20 THEN "20岁以下"
        WHEN age>=20 AND age<=24 THEN "20-24岁"
        WHEN age>=25 THEN "25岁及以上"
        ELSE "其他"
        END) AS age_cut
FROM user_profile;