oracle 创建用户和删除用户命令：

drop user yashangbak cascade;

create user yashangbak identified by "yashangbak";
grant dba to yashangbak with admin option;
alter user yashangbak default role dba;

ORACLE 数据库与删除命令：
1、启动数据库：

oracle@suse92:~> sqlplus /nolog

SQL*Plus: Release 9.2.0.4.0 - Production on Fri Jan 20 02:29:37 2006

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

SQL> connect /as sysdba
Connected to an idle instance.
SQL> startup
ORACLE instance started.

Total System Global Area 135352820 bytes
Fixed Size                    455156 bytes
Variable Size              109051904 bytes
Database Buffers            25165824 bytes
Redo Buffers                  679936 bytes
Database mounted.
2、关闭数据库：
oracle@suse92:~> sqlplus /nolog

SQL*Plus: Release 9.2.0.4.0 - Production on Fri Jan 20 02:29:37 2006

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

SQL> connect /as sysdba
Connected to an idle instance.
SQL> shutdwon abort;
3、启动监听器
oracle@suse92:~> lsnrctl start
4、停止监听器
oracle@suse92:~> lsnrctl stop
5、查看监听器状态
　　oracle@suse92:~> lsnrctl
　　LSNRCTL> status
　　LSNRCTL> exit

lsnrctl start
sqlplus '/as sysdba'
sql> startup
emctl start dbconsole
isqlplusctl start