記一道群友的數(shù)據(jù)分析面試真題，你會(huì)嗎？

老黃博客：https://blog.csdn.net/weixin_41261833/article/details/105739549?utm_source=app

create table student (      id varchar(20),      name varchar(20),      gender char(1),      birth varchar(20),      department varchar(20),      address varchar(20)) charset = utf8;

insert into student values("201901","張大佬","男","1985","計(jì)算機(jī)系","北京市海淀區(qū)"),("201902","郭大俠","男","1986","中文系","北京市昌平區(qū)"),("201903","張三","女","1990","中文系","湖南省永州市"),("201904","李四","男","1990","英語(yǔ)系","遼寧市阜新市"),("201905","王五","女","1991","英語(yǔ)系","福建省廈門市"),("201906","王六","男","1988","計(jì)算機(jī)系","湖南省衡陽(yáng)市");

select     department 院系,    case gender when "男" then 1 else 0 end 男,    case gender when "女" then 1 else 0 end 女from student;

select       院系,      sum(男) 男,      sum(女) 女,      sum(男) + sum(女) as 總計(jì)from(    select department 院系,    case gender when "男" then 1 else 0 end 男,    case gender when "女" then 1 else 0 end 女    from student) agroup by 院系;