CREATE TABLE student
(SNO Varchar(20),
Name Varchar(10),
Age Integer,
College Varchar(30));

CREATE TABLE Course
(CourseID Varchar(15),
CourseNAME Varchar(30),
CourseBeforeID Varchar(15));

CREATE TABLE Choose
(SNO Varchar(20),
CourseID Varchar(30),
Score DECIMAL(5,2));

INSERT
INTO student(SNO,Name,Age,College)
VALUES('S00001','张三',20,'计算机学院');

INSERT
INTO student(SNO,Name,Age,College)
VALUES('S00002','李四',19,'通信学院');

INSERT
INTO student(SNO,Name,Age,College)
VALUES('S00003','张三',21 ,'计算机学院');

INSERT
INTO Course(CourseID,CourseName,CourseBeforeID)
VALUES('C1','计算机引论',NULL);

INSERT
INTO Course(CourseID,CourseName,CourseBeforeID)
VALUES('C2','C 语言 ','C1');

INSERT
INTO Course(CourseID,CourseName,CourseBeforeID)
VALUES('C3','数据结构 ','C2');

INSERT
INTO Choose(SNO,CourseID,Score)
VALUES('S00001','C1 ','95');

INSERT
INTO Choose(SNO,CourseID,Score)
VALUES('S00001','C2 ','80');

INSERT
INTO Choose(SNO,CourseID,Score)
VALUES('S00001','C3 ','84');