PL/SQL中文为乱码，原因是服务器端和客户端编码不一致，解决方法：
1、检查服务器编码：

SQL> select * from v$nls_parameters;

PARAMETER VALUE

---------------------------------------------------------------- ----------------------------------------------------------------

NLS_LANGUAGE SIMPLIFIED CHINESE

NLS_TERRITORY CHINA

NLS_CURRENCY RMB

NLS_ISO_CURRENCY CHINA

NLS_NUMERIC_CHARACTERS .,

NLS_CALENDAR GREGORIAN

NLS_DATE_FORMAT DD-MON-RR

NLS_DATE_LANGUAGE SIMPLIFIED CHINESE

NLS_CHARACTERSET AL32UTF8

NLS_SORT BINARY

NLS_TIME_FORMAT HH.MI.SSXFF AM

NLS_TIMESTAMP_FORMAT DD-MON-RR HH.MI.SSXFF AM

NLS_TIME_TZ_FORMAT HH.MI.SSXFF AM TZR

NLS_TIMESTAMP_TZ_FORMAT DD-MON-RR HH.MI.SSXFF AM TZR

NLS_DUAL_CURRENCY RMB

NLS_NCHAR_CHARACTERSET AL16UTF16

NLS_COMP BINARY

NLS_LENGTH_SEMANTICS BYTE

NLS_NCHAR_CONV_EXCP FALSE

2) 得到服务器端编码为：NLS_LANGUAGE = SIMPLIFIED CHINESE；

3) 进入注册表：HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\HOME0；

4) 修改NLS_LANG = SIMPLIFIED CHINESE；