1，新建用户
create user username identified by password; //username为用户名，password为密码
2，修改用户密码
alter user sys identified by 123456; //修改oracle用户密码
3，授予用户权限
1).grant dba to user
2).grant create session to test; //赋予create session的权限
3).grant create table,create view,create trigger, create sequence,create procedure to test; //分配创建表，视图，触发器，序列，过程 权限
4).grant unlimited tablespace to test; //授权使用表空间
5).grant connect to user; //(这时候的用户必须是sys或者system或者dba。connect具有的权限：alte session || create cluster || create database link || create sequence || create session || create synonym || create table || create view )