SELECT
    IF (`profile` LIKE '%female', 'female', 'male') AS gender,
    COUNT(device_id) AS `number`
FROM
    user_submit
GROUP BY
    gender;

题目:统计每个性别的用户分别有多少参赛者

题解思路:

1.使用LIKE和通配符%匹配出以female结尾的profile并别名为gender

2.以gender来分组,使用统计函数COUNT()计算出各性别分别有多少用户