题解 | #截取出年龄#

select
    age,
    count(user_age.age)as number
from
    (
        select
            substring_index(substring_index(profile, ',', -2), ',', 1) as age
        from
            user_submit
    ) as user_age
group by age

遇到的小插曲 将substring_index 错写成substring。