题解 | #统计每种性别的人数#
统计每种性别的人数
https://www.nowcoder.com/practice/f04189f92f8d4f6fa0f383d413af7cb8
select SUBSTRING_INDEX(profile, ',', -1) as gender, count(*) as number from user_submit group by gender
SUBSTRING_INDEX(profile, ',', -1)
:根据第count个字符对字符串进行分割,如果是正数就是选前边的,是负数则选后边的