CREATE  USER  test  IDENTIFIED  BY  test;
GRANT  CONNECT , CREATE  SYNONYM TO test;
GRANT  SELECT   ON   SCOTT.EMP  TO test;
GRANT  DELETE  ON   SCOTT.EMP TO test;
GRANT  UPDATE  ON  SCOTT.EMP TO test;

CREATE  SYNONYM   staff   FOR  SCOTT.emp;

CREATE   PUBLIC   SYNONYM  pub_emp FOR  SCOTT.emp;

CREATE OR REPLACE PUBLIC SYNONYM  pub_emp FOR SCOTT.emp;

DROP SYNONYM   staff; 
DROP PUBLIC SYNONYM   pub_emp; 

create table  t_testseq
(
    id  number  primary key,
    name varchar2(10)  NOT NULL  
);

create  sequence  seq_value
Start with   1
Increment  by  1;

INSERT INTO  t_testseq 
     VALUES (seq_value.NEXTVAL, ‘tom‘)
INSERT INTO  t_testseq
     VALUES (seq_value.NEXTVAL, ‘jime‘);

SELECT  seq_value.CURRVAL FROM dual;

ALTER SEQUENCE  SEQ_VALUE  MAXVALUE   5000   CYCLE;

DROP   SEQUENCE   SEQ_VALUE;

select dept.deptno,dname,loc,empno,ename,job,mgr,hiredate
from emp,dept
where emp.deptno = dept.deptno  and  dname= ‘ SALES ‘;

--查看当前用户的系统权限
select * from user_sys_privs;
--查看当前用户角色权限
select * from user_role_privs;
--查看某个角色权限
select * from role_sys_privs where role =‘RESOURCE’;

--创建视图
create view dept_emp
as
select dept.deptno,dname,loc,empno,ename,job,mgr,hiredate
from emp,dept
where emp.deptno = dept.deptno;

select * from dept_emp  where dname= ‘ SALES ‘;

create view dept_emp_order
as
select dept.deptno,dname,loc,empno,ename,job,mgr,hiredate
from emp,dept
where emp.deptno = dept.deptno  order by dept.deptno;

create view dept_sal_avg
as
select dname,avg(sal) avg_sal
from dept,emp
where dept.deptno = emp.deptno  group by dname;

update dept_emp
set ename = ‘TOM‘
WHERE empno = 7521;

Select  ename from  dept_emp where empno = 7521

Select  ename from emp where empno = 7521

CREATE  OR REPLACE   [FORCE] VIEW   
  view_name [(alias[, alias]...)] 
  AS  
  select_statement
  [WITH CHECK OPTION]
  [WITH READ ONLY];

DROP VIEW   view_name; 

CREATE  INDEX    索引名    ON   表名 (索引字段)

CREATE  INDEX    idx_ename  ON   emp (ename)

ALTER  INDEX   索引名  REBUILD [REVERSE][NOREVERSE] ; 

ALTER  INDEX  idx_ename  REBUILD;

DROP INDEX   索引名; 

DROP INDEX   idx_ename; 

create table t_testseq
(
  id number,
  name varchar2(10)
);

create sequence seq_value
start with 1
increment by 1;

BEGIN
    FOR  v_temp  in  1..1000000  LOOP
    INSERT  INTO  t_testseq
     values(seq_value.nextval,’abcde’);
    END LOOP;
END;

Set  timing  on;      --sqlplus环境下设置

--常规查询
Select * from t_testseq  where  id = 28900;
--创建索引，再查询
Create  index  idx_testseq_id  on t_testseq(id);

Select  *  from  t_testseq  where  id = 28900;