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'
            WHEN age IS NULL THEN '其他'
        END
    ) AS age_cut
FROM
    user_profile

CASE分支语句过滤出对应年龄范围的人员