SQL 学生 课程 分数

建表

create table course (
  id integer primary key,
  name text not null
);

create table student (
  id integer primary key,
  name text not null
);

create table score (
  id integer primary key,
  course_id integer not null,
  student_id integer not null,
  score integer not null
);

准备数据

insert into course values (1, '语文'), (2, '数学'),(3,'外语');
insert into student values (1, '小张'), (2, '小王'), (3, '小马');

insert into score values (1, 1, 1, 80), (2,2,1,90), (3,3,1,70);
insert into score values (4,1,2,70),(5,2,2,90),(6,3,2,80);
insert into score values (7,1,3,80),(8,2,3,60),(9,3,3,70);