mysql - 子查询作为列 : Nested Subquery

Question

我有两个表“学生”和“团队”。我想根据团队名称显示学生人数，团队的 Team_id 是主键。

我试过这样

(SELECT(SELECT team,count(*) as team 
            FROM student GROUP BY team) AS total,
     (SELECT team_name 
          from team WHERE team_id IN (SELECT team 
              FROM student GROUP BY team)) as team)

我想要输出为

Team Name      Total Student
-----------------------------
Team 1           25
Team 2           10

表“学生”

CREATE TABLE IF NOT EXISTS `student` (
  `id` int(255) NOT NULL AUTO_INCREMENT,
  `rid` varchar(200) NOT NULL,
  `sid` varchar(200) NOT NULL,
  `name` varchar(600) NOT NULL,
  `age` varchar(200) NOT NULL,
  `dob` varchar(200) NOT NULL,
  `sex` varchar(200) NOT NULL,
  `weight` varchar(200) NOT NULL,
  `height` varchar(200) NOT NULL,
  `team` varchar(600) NOT NULL,
  `age_group` varchar(200) NOT NULL,
  `weight_group` varchar(500) NOT NULL,
  `belt` varchar(200) NOT NULL,
  `black_belt` varchar(200) NOT NULL,
  `ikata` varchar(20) NOT NULL,
  `ikumite` varchar(20) NOT NULL,
  `team_kata` varchar(20) NOT NULL,
  `special_entry` varchar(20) NOT NULL,
  `challange` varchar(50) NOT NULL,
  `state` varchar(200) NOT NULL,
  `weapon` varchar(200) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=6 DEFAULT CHARSET=latin1;

表“团队”

CREATE TABLE IF NOT EXISTS `team` (
  `id` int(20) NOT NULL AUTO_INCREMENT,
  `team_id` varchar(500) NOT NULL,
  `team_name` varchar(500) NOT NULL,
  `address` varchar(500) NOT NULL,
  `coach_name` varchar(500) NOT NULL,
  `coach_number` varchar(500) NOT NULL,
  `coach_email` varchar(500) NOT NULL,
  `gold` varchar(200) NOT NULL,
  `state` varchar(500) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=4 DEFAULT CHARSET=latin1;

Answer 1

看来你正在寻找这个

 select a.team_name, count(*) 
 from  team as a
 inner join student as b on a.id = b.team
 group by a.team_name

(使用合适的列加入)