表名称:course_trainer_combination
创建表查询语句:
create table `course_trainer_combination` (
`id` double ,
`course` varchar (150),
`trainer` varchar (150),
`distance` float
);
insert into `course_trainer_combination` (`id`, `course`, `trainer`, `distance`) values('1','Course A','Trainer A','110.00');
insert into `course_trainer_combination` (`id`, `course`, `trainer`, `distance`) values('2','Course A','Trainer B','105.00');
insert into `course_trainer_combination` (`id`, `course`, `trainer`, `distance`) values('3','Course A','Trainer C','115.00');
insert into `course_trainer_combination` (`id`, `course`, `trainer`, `distance`) values('4','Course B','Trainer A','112.00');
insert into `course_trainer_combination` (`id`, `course`, `trainer`, `distance`) values('5','Course B ','Trainer B','108.00');
insert into `course_trainer_combination` (`id`, `course`, `trainer`, `distance`) values('6','Course B','Trainer C','109.00');
insert into `course_trainer_combination` (`id`, `course`, `trainer`, `distance`) values('7','Course C','Trainer A','124.00');
insert into `course_trainer_combination` (`id`, `course`, `trainer`, `distance`) values('8','Course C','Trainer B','128.00');
insert into `course_trainer_combination` (`id`, `course`, `trainer`, `distance`) values('9','Course C','Trainer C','121.00');
我的表格长这样
期望的结果:
2 | Course A | Trainer B | 105
6 | Course B | Trainer C | 109
7 | Course C | Trainer A | 124