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 gender,count(*) AS number
FROM
(
SELECT MID(profile,15) AS gender
FROM user_submit
) AS NEWTABLE
GROUP BY gender
运用嵌套查询，先将性别信息建立一个新表，再从新表中查询
