· 8 years ago · Nov 26, 2017, 12:22 PM
1/*外键是自己本身该如何处ç†æ’入问题*/
2 create table if not exists Course(
3 Cno varchar(10) primary key,
4 Cname varchar(100) not null,
5 Cpno varchar(10),
6 Ccredit tinyint,
7
8 foreign key (cpno) references course(cno)
9);
10/* the under sql will across error */
11insert into Course(cno,cname,cpno,ccredit) value("1","æ•°æ®åº“","5",4);
12insert into Course(cno,cname,cpno,ccredit) value("2","æ•°å¦",null,2);
13insert into Course(cno,cname,cpno,ccredit) value("3","ä¿¡æ¯ç³»ç»Ÿ","1",4);
14insert into Course(cno,cname,cpno,ccredit) value("4","æ“作系统","6",3);
15insert into Course(cno,cname,cpno,ccredit) value("5","æ•°æ®ç»“æž„","7",4);
16insert into Course(cno,cname,cpno,ccredit) value("6","æ•°æ®å¤„ç†",null,2);
17insert into Course(cno,cname,cpno,ccredit) value("7","PASCALè¯è¨€","6",4);