Oracle关键表创建

 

--"一对一"关系表的创建
--主表
create table tab_student
(
id number,
name varchar2(32),
address varchar2(32),
primary key(id)
);
--从表
create table tab_IdCard
(
sid number primary key,
num number unique not null,
foreign key(sid) reference tab_primary(id)
);

--"一对多"关系表的创建
--一方
create table tab_class
(
cid number primary key,
classname varchar2(20),
desc varchar2(50)
);
--多方
create table tab_student
(
stuid number primary key,
claid number,
name varchar2(32),
address varchar2(32),
foreign key(claid) reference tab_class(cid)
);

--"多对多"关系表的创建
create table tab_class
(
id number primary key,
name varchar2(20)
);

create table tab_course
(
id number primary key,
name varchar2(20)
);

create table tab_class_course
(
classid number not null,
courseid number not null,
primary key(classid,courseid);
);

alter table tab_class_course
add constraint fk_class
foreign key(classid)
reference tab_class(id);

alter table tab_class_course
add constraint fk_course
foreign key(courseid)
reference tab_course(id);