我有3个表,students,courses,enroll和关系为“学生注册课程”
我以sid作为主键创建了students表
我以cid作为主键创建了courses表
现在我必须创建enroll表,我这样做了,但它显示了一个错误的关键字references,是什么错误?
create table enroll(
grade char(2),
sid int not null,
cid int not null,
primary key(sid,cid),
foreign key cid references courses on delete cascade,
foreign key sid references students on delete cascade
);发布于 2012-04-14 02:04:44
我认为您需要将cid和sid放在大括号中。这是一个样例代码,试一试,让你知道你的结果。请确保引用的大小和数据类型,即课程和学生的主键与注册的主键相同。
CREATE TABLE `enroll` (
`sid` INT(10) NOT NULL,
`cid` INT(10) NOT NULL,
PRIMARY KEY (`sid`, `cid`),
INDEX `FK_enroll_course` (`cid`),
CONSTRAINT `FK_enroll_course` FOREIGN KEY (`cid`) REFERENCES `course` (`id`) ON DELETE CASCADE,
CONSTRAINT `FK_enroll_student` FOREIGN KEY (`sid`) REFERENCES `student` (`id`) ON DELETE CASCADE
)https://stackoverflow.com/questions/10145784
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