MySQL FOREIGN KEY 約束報錯
問題描述
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 ‘計算機系’);
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:
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!
問題解答
回答1:創(chuàng)建外鍵的寫法錯誤吧,
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