613.txt

关于oracle和sql的书籍和ppt教程,非常好,本人珍藏品

/*
create table xuesheng(id int , name varchar2(10),age int);

create table course(id int , name varchar2(20),xuefen int)

 
alter table xuesheng 
add sex char(10);

alter table xuesheng
modify (sex char(2));


select age as nianling from students ;
rename xuesheng to students;
alter table students
add constraint pk_xuesheng_id primary key(id);

 drop table xueshengchengji;
 create table xueshengchengji(sid int ,cid int ,chengji int);



alter table course
add constraint pk_course_id primary key(id);

alter table xueshengchengji
add constraint pk_xuesheng_sid_cid primary key(sid,cid);

alter table xueshengchengji
add constraint fk_xue_sid  foreign key(sid) references students(id);

alter table xueshengchengji
add constraint fk_xue_cid  foreign key(cid) references course(id);

alter table students
add constraint stu_uni_name unique(name); 

alter table students
add constraint check_stu_age check((age > 0) and (age < 100));

alter table students
modify(name not null);

约束 
not null
check
unique
primary key
foreign key
*/
--create table course(id int , name varchar2(20),xuefen int);


--create table temptt(id int primary key,name varchar2(10) primary key);


/*create view stu_tea_view 
as
select t.id tid,t.name tname,s.id sid,s.name sname
from teacher t, student s
where t.id = s.tid */
-- Create sequence 
create sequence SEQ
minvalue 1
maxvalue 999999999999999999999999999
start with 13
increment by 1
cache 20;