题解 | #截取出年龄#
截取出年龄
https://www.nowcoder.com/practice/b8d8a87fe1fc415c96f355dc62bdd12f
select age,count(*) as number from (select substring_index(profile,',',-1) as age from (select substring_index(profile,',',3) as profile from user_submit) p ) t group by age