select s.stuid,s.stuname,s.stuage,s.gender,cl.classesname
from student s,classes cl
where s.classesid = cl.classesid
;select s.stuid,s.stuname,s.stuage,s.gender,cl.classesname
from student s inner join classes cl on(s.stuid = cl.classesid)
where gender='男'
;
create
table student(
stuid number(6) primary
key,
stuname nvarchar2(50) not
null,
stugender nvarchar2(4) not
null,
stuage number(4) default
18, address number(6),
phone number(11),
classesid number(6)
);create
table classes(
classesid number(6) primary
key,
classesname nvarchar2(50) not
null
);create
table address(
addid number(6),
addstreet nvarchar2(20),
addnum nvarchar2(20),
constraint address_pk primary
key (addid)
);alter
table student add
constraint student_classes_fk
foreign
key (classesid) references classes(classesid);
alter
table student add
constraint student_address_fk
foreign
key (address) references address(addid);
commit;
drop sequence stu_seq;
create sequence stu_seq
start
with
1increment by
1nomaxvalue
nocycle
cache 10;
drop sequence class_seq;
create sequence class_seq
start
with
1increment by
1nomaxvalue
nocycle
cache 10;
create sequence add_seq
start
with
1increment by
1nomaxvalue
nocycle
cache 10;
insert
into classes values(class_seq.nextval,'書法班');
insert
into classes values(class_seq.nextval,'鋼琴班');
insert
into classes values(class_seq.nextval,'跆拳道班');
insert
into classes values(class_seq.nextval,'舞蹈班');
insert
into classes values(class_seq.nextval,'小主持人');
commit;
select * from classes;
insert
into address
values(add_seq.nextval,'蓮花街',null);
insert
into address
values(add_seq.nextval,'科學大道',null);
insert
into address
values(add_seq.nextval,'雪松路',null);
insert
into address
values(add_seq.nextval,'銀屏路',null);
insert
into address
values(add_seq.nextval,'石南路',null);
insert
into address
values(add_seq.nextval,'瑞達路',null);
commit;
select * from address;
insert
into student values(stu_seq.nextval,'tom','男',22,3,'123456',1);
insert
into student values(stu_seq.nextval,'jerry','男',23,6,'123456',3);
insert
into student values(stu_seq.nextval,'sanmao','男',18,1,'123456',1);
insert
into student values(stu_seq.nextval,'ruhua','女',19,5,'123456',2);
insert
into student values(stu_seq.nextval,'mray','女',24,3,'123456',3);
commit;
select * from student;
select st.stuid stuid,st.stuname sname,st.stugender sgen,st.stuage age,
ad.addstreet adds,st.phone ph,cl.classesname cname
from student st,classes cl,address ad
where st.classesid = cl.classesid and st.address = ad.addid;
select st.stuid stuid,st.stuname sname,st.stugender sgen,st.stuage age,
ad.addstreet adds,st.phone ph,cl.classesname cname
from classes cl inner
join student st
on(cl.classesid=st.classesid)
inner
join address ad
on(ad.addid=st.address);
--左外鏈結--
select st.stuid stuid,st.stuname sname,ad.addstreet adds
from address ad left
outer
join student st
on(ad.addid=st.address);
select st.stuid stuid,st.stuname sname,ad.addstreet adds
from address ad,student st
where ad.addid = st.address(+);
--右外連線--
select st.stuid stuid,st.stuname sname,ad.addstreet adds
from student st right
outer
join address ad
on(ad.addid=st.address);
select st.stuid stuid,st.stuname sname,ad.addstreet adds
from student st,address ad
where st.address(+)=ad.addid;
select cid,cname from(
select cl.classesid cid,cl.classesname cname,st.stuid stuid
from classes cl left
outer
join student st
on(cl.classesid = st.classesid)
) where stuid is
null;
--行號和行標示--
select rowid from student;
select rownum from student;
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