本篇文章主要介绍了"ORACLE基础语句-建表"，主要涉及到方面的内容，对于Oracle感兴趣的同学可以参考一下：
oracle建表语法为：create table 表名( 列名 数据类型 是否非空 约束信息,列名 数据类型 是否非空 约束信息,列名 数据类型 是否非空 约束...
select * from xsxk
create view classstu as select s.id,c.classname,s.stu_name from students s,classes c where c.id=s.class_id;
drop view classstu; --删除视图
select * from classstu;
create view stu_couse_view as select s.id ,c.couse_name from stu_couse sc,students s,couse c where s.id=sc.stu_id and sc.couse_id=c.couse_id;
select * from stu_couse_view;
create view csc as select cs.classname,cs.stu_name,scv.couse_name from classstu cs,stu_couse_view scv where cs.id=scv.id;
select * from csc;
select * from classes cross join students; --全连接，相当于select * from classes,students;
select * from classes cl left join students s on cl.id=s.class_id; --左连接 不管左表有没有 都显示出来
select * from classes cl right join students s on cl.id=s.class_id; --右连接
select * from classes cl full join students s on cl.id=s.class_id; --全连接
insert into classes values(class_seq.nextval,'软件四班');
create table sales(
nian varchar2(4),
yeji number(5)
);
insert into sales values('2001',200);
insert into sales values('2002',300);
insert into sales values('2003',400);
insert into sales values('2004',500);
commit;
select * from sales;
drop table sale;
select s1.nian,sum(s2.yeji) from sales s1,sales s2 where s1.nian>=s2.nian group by s1.nian order by s1.nian desc;
select s1.nian,sum(s2.yeji) from sales s1,sales s2 where s1.nian>=s2.nian group by s1.nian;
s
年 年业绩总和
2001 200
2002 500
2003 900
2004 1400
