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