oracle命令建立主键外键

1、创建一张学生表

SQL> create table t_stu(
  2  stuid number(10) primary key,
  3  stuname varchar2(20) not null,
  4  stusex varchar2(2) default '男' check(stusex in('男','女')));
 
Table created
 
Executed in 0.547 seconds

2、创建一张课程表

SQL> create table t_couse(
  2  couseid number(10) primary key,
  3  cousename varchar2(20) not null,
  4  cousetype varchar2(4));
 
Table created
 
Executed in 0.062 seconds

3、创建一张学生课程成绩表（包括主外键）

SQL> create table t_score(
  2  scoreid number(10) primary key,
  3  stuid number(10) references t_stu(stuid),
  4  couseid number(10),
  5  constraint fk_couseid foreign key(couseid)
  6  references t_couse(couseid)
  7  on delete cascade);
 
Table created