题解 | #截取出年龄#
截取出年龄
http://www.nowcoder.com/practice/b8d8a87fe1fc415c96f355dc62bdd12f
select SUBSTRING_INDEX(SUBSTRING_INDEX(profile,',',-2),',',1) as age, count(device_id) as number From user_submit Group by age #subtring_index左右两边限制需要嵌套 #也可用substring(profile,12,2)