create view v_emp_10_liqi
as
select empno, ename, sal, deptno from emp_liqi where deptno = 10
desc v_emp_10_liqi
select * from v_emp_10_liqi
create or replace view v_emp_10_liqi
as
select empno id, ename name, sal salary, deptno
from emp_liqi where deptno = 10
with read only
insert into v_emp_10_liqi values (8088, 'BOSS', 100, 10)
delete from v_emp_10_liqi where id = 8088 and name = 'BOSS'
WITH CHECK OPTION
select object_name from user_objects
create view v_emp_salary_liqi
as
select d.dname, avg(e.sal) avg_sal, sum(e.sal) sum_sal, max(e.sal) max_sal,
min(e.sal) min_sal
from emp_liqi e join dept_liqi d
on e.deptno = d.deptno
group by d.dname
select * from v_emp_salary_liqi
create sequence emp_seq_liqi
start with 100
increment by 10
select emp_seq_liqi.nextval from dual
select * from user_sequen
insert into emp_liqi(empno, ename, sal, deptno)values
(emp_seq_liqi.nextval,'LISI',3000,10)
select * from emp_liqi
create index idx_emp_liqi_ename on emp_liqi(ename)
create index emp_liqi_ename_upper_idx on emp_liqi(upper(ename))
drop index emp_liqi_ename_upper_idx
alter table emp_liqi
modify (ename varchar2(10) not null)
desc emp_liqi
insert into emp_liqi(empno, ename)
values(7499,'xxxx')
alter table emp_liqi
add constraint emp_liqi_ename_uk unique(ename)
alter table emp_liqi drop constraint constraint_ename
--uuid 生成32位的字符串
select sys_guid() from dual