转移密码中的@符号

有用户问到这样一个问题，在进行导出操作时如何转义口令中的@符号？
由于缺省的Oracle会将@符号后面的字串当作服务名来解析，所以不加处理是不行的。
有的企业因为安全规则的需要，口令中都会加入@符号。

假定用户口令如下：

SQL> alter user antiper identified by "";

User altered.

如果缺省导出会出现如下错误：

[oracle@jumper oracle]$ exp file=antiper.dmp tables=test

Export: Release 9.2.0.4.0 - Production on Fri Jan 4 11:17:48 2008
Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

EXP-00056: ORACLE error 12154 encountered
ORA-12154: TNS:could not resolve service name
EXP-00000: Export terminated unsuccessfully

通过转义，可以成功导出：

[oracle@jumper oracle]$ exp antiper/\"" file=antiper.dmp tables=test

Export: Release 9.2.0.4.0 - Production on Fri Jan 4 11:12:10 2008
Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

Connected to: Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production
Export done in ZHS16GBK character set and AL16UTF16 NCHAR character set

About to export specified tables via Conventional Path ...
. . exporting table                          TEST      4136 rows exported