Create table Student
(
Sno varchar(7) primary key,
Sname varchar(10) not null,
Ssex char (2) check(Ssex=‘男’or Ssex=’女’),
Sage int check(Sage between 15 and 45),
Sdept varchar(20) default ‘计算机系’
);
Create table course
(
Cno varchar(10) primary key,
Cname varchar(20) not null,
Ccredit int check(Sctedit>0),
Semester int check(Semester>0),
Period int check(Period>0)
);
Create table SC
(
Sno varchar(7) foreign key references student(Sno),
Cno varchar(10) foreign key references course(Cno),
Grade int check(Grade between 0 and 100),
Primary key (Sno,Cno)
);
前兩個可以成功的建表,但是第三個建表報錯誤:
#更改第三個:
Create table SC
(
Sno varchar(7),
Cno varchar(10),
Grade int check(Grade between 0 and 100),
foreign key (Sno) references student(Sno),
foreign key (Cno) references course(Cno),
Primary key (Sno,Cno),
);
還是報錯:
#求解答,謝謝大佬!
創建外鍵的寫法錯誤吧,