题解 | #查看不同年龄段的用户明细#

SELECT device_id, gender, '20岁以下' AS age_cut
FROM user_profile
WHERE age<20
UNION ALL
SELECT device_id, gender, '20-24岁' AS age_cut
FROM user_profile
WHERE age between 20 AND 24
UNION ALL
SELECT device_id, gender, '25岁及以上' AS age_cut
FROM user_profile
WHERE age>=25
UNION ALL
SELECT device_id, gender, '其他' AS age_cut
FROM user_profile
WHERE age is NULL
ORDER BY device_id