数据库怎么通过写代码级联删除，代码尽量简单？

Question

create table student(
sno char(9) primary key,
sname varchar(20),
ssex char(2),
sage smallint,
sdept varchar(20));

create table course(
cno char(4) primary key,
cname varchar(40),
cpno char(4),
ccredit smallint,
foreign key(cpno) references course(cno));

 

create table sc(
sno char(9),
cno char(4),
grade smallint,
primary key(sno,cno),
foreign key(sno) references student(sno),

foreign key(cno) references course(cno));

 

insert into student values('200215121','李勇','男',20,'CS');
insert into student values('200215122','刘晨','女',19,'CS');
insert into student values('200215123','王敏','女',18,'MA');
insert into student values('200215124','张立','男',19,'IS');

insert into COURSE values('0002','数学',NULL,2);
insert into COURSE values('0006','数据处理',NULL,2);
insert into COURSE values('0007','PASCAL语言','0006',4);
insert into COURSE values('0005','数据结构','0007',4);
insert into COURSE values('0001','数据库','0005',4);
insert into COURSE values('0003','信息系统','0001',4);
insert into COURSE values('0004','操作系统','0006',3);

insert into sc values('200215121','0001',92);
insert into sc values('200215121','0002',85);
insert into sc values('200215121','0003',88);
insert into sc values('200215122','0002',90);
insert into sc values('200215122','0003',80);
insert into sc values('200215123','0001',93);
insert into sc values('200215124','0001',90);

 

然后我要删除6号课程记录会报错怎么删除求大神指导

Answer 1

---- 1、删除 USE testdb2 GO IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[student]') AND type IN (N'U')) DROP TABLE [student]; IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[course]') AND type IN (N'U')) DROP TABLE [course]; IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[sc]') AND type IN (N'U')) DROP TABLE [sc]; create table student(sno char(9) primary key,sname varchar(20),ssex char(2),sage smallint,sdept varchar(20)); create table course(cno char(4) primary key,cname varchar(40),cpno char(4),ccredit smallint); create table sc(sno char(9),cno char(4),grade smallint, primary key(sno,cno),foreign key(sno) references student(sno), foreign key(cno) references course(cno) on delete cascade ); insert into student values('200215121','李勇','男',20,'CS'); insert into student values('200215122','刘晨','女',19,'CS'); insert into student values('200215123','王敏','女',18,'MA'); insert into student values('200215124','张立','男',19,'IS'); insert into COURSE values('0002','数学',NULL,2); insert into COURSE values('0006','数据处理',NULL,2); insert into COURSE values('0007','PASCAL语言','0006',4); insert into COURSE values('0005','数据结构','0007',4); insert into COURSE values('0001','数据库','0005',4); insert into COURSE values('0003','信息系统','0001',4); insert into COURSE values('0004','操作系统','0006',3); insert into sc values('200215121','0001',92); insert into sc values('200215121','0002',85); insert into sc values('200215121','0003',88); insert into sc values('200215122','0002',90); insert into sc values('200215122','0003',80); insert into sc values('200215123','0001',93); insert into sc values('200215124','0006',90); DELETE FROM course WHERE cno = '0006' ; select * from course c select * from student s select * from sc

Answer 2

你要先删外建表的记录，如sc 、student表对应的外建记录

Answer 3

触发器试试

Answer 4

你在外键加上 on delete cascade

Answer 5

具体在哪里，说清楚一点谢谢，本人刚学

Answer 6

@米老鬼: 

Answer 7

@刘宏玺: 我用的不是这个软件，是Microsoft sql好像只能写代码吧，能不能说一下怎么通过写代码实现级联删除还有写在什么地方

Answer 8

@米老鬼: …………