题解 | #截取出年龄#
截取出年龄
https://www.nowcoder.com/practice/b8d8a87fe1fc415c96f355dc62bdd12f
select
substring_index (substring_index (profile, ',', -2), ',', 1) as age,
count(*) as number
from
user_submit
group by
age;
substring_index 也不是那么好用