oracle10g里怎么样重命名表名，列名

最近整天弄mysql，oracle语法都生疏了，正好练练，复习，再学习的过程。
但愿是帮你，不是害你。

1.---
alter user sys identified by orcale;
alter user system identified by orcale;

2.---
create tablespace ts_estore 
datafile 'filespec' size 1m 
autoextend on next 500k
extent management local uniform size 128k;

3.---
create user estore identified by estore 
default tablespace ts_estore;

4.---
grant connect,resource 8 privs,create any table,alter any table,delete any table,
create any view,delete any view to estore;
--resource 8 privs 具有程序开发最的权限 (??)

5.---
connect estore/estore

create table users ( 
id number not null primary key,
username varchar2(30),
userpass varchar2(8),
useraddr varchar2(80),
useremail varchar2(60),
created date default sysdate);

create sequence s_users start with 1 increment by 1;

create or replace triggrt users_id_trigger 
before insert on users for each now
declare
next_no number;
begin
select s_users.nextval into next_no from dual;
:new.id :=next_no;
end;

6.---
insert into users (username,userpass,useraddr,useremail) values ("张三","zhang3","师大","zhang3@sina.com");
insert into users (username,userpass,useraddr,useremail) values ("李四","li4","师大","li4@sina.com");
insert into users (username,userpass,useraddr,useremail) values ("王五","wang5","师大","li4@sina.com");

7.---
set serveroutput on

declare
uid users.id%type;
uname users.username%type;
upass users.userpass%type;
uaddr users.useraddr%type;
umail users.useremail%type;
ucreatedtime users.created%type;
cursor mycur is select * from users;
begin

open mycur;
fetch mycur into uid,uname,upass,uaddr,umail,ucreatedtime;
dbms_output.put_line("loop循环输出:");
loop
dbms_output.put_line(uid||" "||uname||" "||upass||" "||uaddr||" "||umail||" "||ucreatedtime);
exit when mycur%notfound;
end loop;
close mycur;

open mycur;
fetch mycur into uid,uname,upass,uaddr,umail,ucreatedtime;
dbms_output.put_line("while循环输出:");
while mycur%found loop
dbms_output.put_line(uid||" "||uname||" "||upass||" "||uaddr||" "||umail||" "||ucreatedtime);
end loop;
close mycur;

end;

8.---
set serveroutput on

declare
begin
dbms_output.put_line("for语句隐式游标循环输出:");
for my_record in (select * from users) loop
dbms_output.put_line(my_record.uid||" "||my_record.uname||" "||my_record.upass||" "||my_record.uaddr||" 

"||my_record.umail||" "||my_record.ucreatedtime);
end loop;
end;

9.---
set serveroutput on

create or replace p_login (userid in users.id%type,password in users.userpass%type)
as
user_count number;
user_not_exist exception;
user_pass_error exception;
begin
select count(1) into user_count from users where id = userid;
if user_count = 0 then raise user_not_exist;
elsif user_count<>0 then
select count(1) into user_count from users where id = userid and userpass = password;
if user_count = 0 then raise user_pass_error;
elsif user_count <> 0 then 
dbms_output.put_line("用户名密码正确!!");
endif;
endif;
exception
when user_not_exist then dbms_output.put_line("用户不存在");
when user_pass_error then dbms_output.put_line("用户密码错误");
end;

10.---
create table user_log
(op varchar2(10),
id number,
oldid number,
newid number
updatedtime date);

create sequence s_user_log start with 1 increment by 1;

create or replace triggrt users_op_trigger 
after insert or update or delete on users 
for each now
begin
if inserting then
insert into user_log values ("insert",s_user_log.nextval,old.id,new.id,sysdate);
elsif updating then 
insert into user_log values ("update",s_user_log.nextval,old.id,new.id,sysdate);
elsif deleting then 
insert into user_log values ("delete",s_user_log.nextval,old.id,old.id,sysdate);
endif;
end;

all。。
呃，手都冻僵了。谁帮我呵一下。。。