题解 | 截取出年龄
截取出年龄
https://www.nowcoder.com/practice/b8d8a87fe1fc415c96f355dc62bdd12f
select substring(substring_index(profile,',',-2),1,2) 'age',count(device_id) 'number' from user_submit group by age;
先使用substring_index(profile,',',-2)提取出来后面两个整体数据,再使用substring提取出年龄