我们在项目开发中,Oracle数据也会不断变化,因此需要定期将开发库数据库导入到测试数据库中。通常的做法是ldquo;三部曲:rdqu
我们在项目开发中,Oracle数据也会不断变化,因此需要定期将开发库数据库导入到测试数据库中。通常的做法是“三部曲:”
1.从开发库中exp导出数据
2.删除测试库用户
3.使用imp把导出数据导入到测试库
今天同事问我可不可以保留之前的用户,比如给用户改个名称。我之前倒没想过这个问题,说应该可以吧,使用alter user *** rename to ***;语句。需要上机验证一下,一操作就傻眼了,Oracle 10g不支持用户重命名,从Oracle 11.2.0.2才开始提供用户重命名的新特性。
Oracle 10g 不支持用户重命名
1.环境准备
我们在Oracle 10g中进行试验。
C:\\Users\\Administrator>sqlplus sys/hoegh as sysdba
SQL*Plus: Release 10.2.0.4.0 - Production on 星期四 5月 14 09:17:02 2015
Copyright (c) 1982, 2007, Oracle. All Rights Reserved.
连接到:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL>
SQL> select * from v$version;
BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bi
PL/SQL Release 10.2.0.4.0 - Production
CORE 10.2.0.4.0 Production
TNS for 64-bit Windows: Version 10.2.0.4.0 - Production
NLSRTL Version 10.2.0.4.0 - Production
SQL>
2.重命名用户报错
执行alter user *** rename to ***;语句,数据库报错,如下所示:
SQL>
SQL> alter user scott rename to tiger;
alter user scott rename to tiger
*
第 1 行出现错误:
ORA-00922: 选项缺失或无效
SQL>
SQL> alter user scott rename to tiger identified by scott;
alter user scott rename to tiger identified by scott
*
第 1 行出现错误:
ORA-00922: 选项缺失或无效
SQL>
SQL>
Oracle 11g用户重命名
1.环境准备
我们在Oracle 11g中进行试验。
SQL>
SQL> select * from v$version;
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production
PL/SQL Release 11.2.0.3.0 - Production
CORE 11.2.0.3.0 Production
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production
SQL>
2.修改Oracle的隐含参数"_enable_rename_user"
通常,在sqlplus中使用show parameter xx可以查看到Oracle定义的参数, 它是通过查询v$parameter获得的。 另外Oracle中还有一些隐含的参数 无法直接通过show parameter的方式查询,,也就是我们接下来使用到的隐含参数。修改隐含参数时, 使用alter system set "parameter_name"=value scope=both;其中有些可以在memory更改而有些仅仅可以通过spfile更改, 试试就知道了。需要注意的是一定要加上双引号, 另外引号内不能有空格, 只能包含参数的名字。
点击(此处)折叠或打开
SQL>
SQL> show parameter process --通过show parameter查看参数
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
aq_tm_processes integer 1
cell_offload_processing boolean TRUE
db_writer_processes integer 1
gcs_server_processes integer 0
global_txn_processes integer 1
job_queue_processes integer 1000
log_archive_max_processes integer 4
processes integer 150
processor_group_name string
SQL>
SQL> show parameter enable_rename --无法通过show parameter查看隐含参数
SQL> show parameter rename
SQL>
SQL>
SQL> alter system set \"_enable_rename_user\"=true scope=spfile;
System altered.
SQL>
3.用RESTRICTED模式启动数据库
用户重命名操作必须在RESTRICTED模式下完成。需要注意的是RESTRICTED模式以后 除了管理员都不能登录,如果需要非管理员登录,必须授予权限GRANT restricted session to username;
点击(此处)折叠或打开
SQL>
SQL> startup restrict force
ORACLE instance started.
Total System Global Area 941600768 bytes
Fixed Size 1348860 bytes
Variable Size 629148420 bytes
Database Buffers 306184192 bytes
Redo Buffers 4919296 bytes
Database mounted.
Database opened.
SQL>
SQL>
SQL> select status from v$instance;
STATUS
------------
OPEN
SQL>
SQL> select open_mode,name from v$database;
OPEN_MODE NAME
-------------------- ---------
READ WRITE HOEGH
SQL>
4.修改用户名
在执行重命名操作时,必须重新指定密码,否则会报错。
SQL>
SQL> alter user scott rename to tiger;
alter user scott rename to tiger
*
ERROR at line 1:
ORA-02000: missing IDENTIFIED keyword
SQL> alter user scott rename to tiger identified by scott;
User altered.
SQL>
5.重启数据库
SQL>
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL>
SQL>
SQL> startup
ORACLE instance started.
Total System Global Area 941600768 bytes
Fixed Size 1348860 bytes
Variable Size 629148420 bytes
Database Buffers 306184192 bytes
Redo Buffers 4919296 bytes
Database mounted.
Database opened.
SQL>
6.确认结果
原来的scott用户已经被重命名为tiger用户,现在,我们验证一下tiger用户是否能够正常登陆,原来的scott用户是否还存在。
SQL> conn scott/tiger
ERROR:
ORA-01017: invalid username/password; logon denied
Warning: You are no longer connected to ORACLE.
SQL>
SQL> conn tiger/scott
Connected.
SQL>
SQL> select * from cat;
TABLE_NAME TABLE_TYPE
------------------------------ -----------
BONUS TABLE
DEPT TABLE
EMP TABLE
HOEGH TABLE
SALGRADE TABLE
SQL>
本文永久更新链接地址:

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