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 eygle identified by "eygle@com";
User altered.
如果缺省导出会出现如下错误：
[oracle@jumper oracle]$ exp eygle/eygle@com file=eygle.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 eygle/"eygle@com" file=eygle.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
-The End-