1、 USERENV(OPTION)　　返回当前的会话信息.

OPTION=‘ISDBA‘若当前是DBA角色,则为TRUE,否则FALSE.

OPTION=‘LANGUAGE‘返回数据库的字符集.

OPTION=‘SESSIONID‘为当前会话标识符.

OPTION=‘ENTRYID‘返回可审计的会话标识符.

OPTION=‘LANG‘返回会话语言名称的ISO简记.

OPTION=‘INSTANCE‘返回当前的实例.

OPTION=‘terminal‘返回当前计算机名

SELECT USERENV(‘LANGUAGE‘) FROM DUAL;

2、sys_context

select

SYS_CONTEXT(‘USERENV‘,‘TERMINAL‘) terminal,

SYS_CONTEXT(‘USERENV‘,‘LANGUAGE‘) language,

SYS_CONTEXT(‘USERENV‘,‘SESSIONID‘) sessionid,

SYS_CONTEXT(‘USERENV‘,‘INSTANCE‘) instance,

SYS_CONTEXT(‘USERENV‘,‘ENTRYID‘) entryid,

SYS_CONTEXT(‘USERENV‘,‘ISDBA‘) isdba,

SYS_CONTEXT(‘USERENV‘,‘NLS_TERRITORY‘) nls_territory,

SYS_CONTEXT(‘USERENV‘,‘NLS_CURRENCY‘) nls_currency,

SYS_CONTEXT(‘USERENV‘,‘NLS_CALENDAR‘) nls_calendar,

SYS_CONTEXT(‘USERENV‘,‘NLS_DATE_FORMAT‘) nls_date_format,

SYS_CONTEXT(‘USERENV‘,‘NLS_DATE_LANGUAGE‘) nls_date_language,

SYS_CONTEXT(‘USERENV‘,‘NLS_SORT‘) nls_sort,

SYS_CONTEXT(‘USERENV‘,‘CURRENT_USER‘) current_user,

SYS_CONTEXT(‘USERENV‘,‘CURRENT_USERID‘) current_userid,

SYS_CONTEXT(‘USERENV‘,‘SESSION_USER‘) session_user,

SYS_CONTEXT(‘USERENV‘,‘SESSION_USERID‘) session_userid,

SYS_CONTEXT(‘USERENV‘,‘PROXY_USER‘) proxy_user,

SYS_CONTEXT(‘USERENV‘,‘PROXY_USERID‘) proxy_userid,

SYS_CONTEXT(‘USERENV‘,‘DB_DOMAIN‘) db_domain,

SYS_CONTEXT(‘USERENV‘,‘DB_NAME‘) db_name,

SYS_CONTEXT(‘USERENV‘,‘HOST‘) host,

SYS_CONTEXT(‘USERENV‘,‘OS_USER‘) os_user,

SYS_CONTEXT(‘USERENV‘,‘EXTERNAL_NAME‘) external_name,

SYS_CONTEXT(‘USERENV‘,‘IP_ADDRESS‘) ip_address,

SYS_CONTEXT(‘USERENV‘,‘NETWORK_PROTOCOL‘) network_protocol,

SYS_CONTEXT(‘USERENV‘,‘BG_JOB_ID‘) bg_job_id,

SYS_CONTEXT(‘USERENV‘,‘FG_JOB_ID‘) fg_job_id,

SYS_CONTEXT(‘USERENV‘,‘AUTHENTICATION_TYPE‘) authentication_type,

SYS_CONTEXT(‘USERENV‘,‘AUTHENTICATION_DATA‘) authentication_data

from dual

3.与系统视图v$session组合使用可以获得更多信息(客户端所使用的应用程序等)

select *

from v$session se,

(select SYS_CONTEXT(‘USERENV‘, ‘TERMINAL‘) terminal,

SYS_CONTEXT(‘USERENV‘, ‘LANGUAGE‘) language,

SYS_CONTEXT(‘USERENV‘, ‘SESSIONID‘) sessionid,

SYS_CONTEXT(‘USERENV‘, ‘INSTANCE‘) instance,

SYS_CONTEXT(‘USERENV‘, ‘ENTRYID‘) entryid,

SYS_CONTEXT(‘USERENV‘, ‘ISDBA‘) isdba,

SYS_CONTEXT(‘USERENV‘, ‘NLS_TERRITORY‘) nls_territory,

SYS_CONTEXT(‘USERENV‘, ‘NLS_CURRENCY‘) nls_currency,

SYS_CONTEXT(‘USERENV‘, ‘NLS_CALENDAR‘) nls_calendar,

SYS_CONTEXT(‘USERENV‘, ‘NLS_DATE_FORMAT‘) nls_date_format,

SYS_CONTEXT(‘USERENV‘, ‘NLS_DATE_LANGUAGE‘) nls_date_language,

SYS_CONTEXT(‘USERENV‘, ‘NLS_SORT‘) nls_sort,

SYS_CONTEXT(‘USERENV‘, ‘CURRENT_USER‘) current_user,

SYS_CONTEXT(‘USERENV‘, ‘CURRENT_USERID‘) current_userid,

SYS_CONTEXT(‘USERENV‘, ‘SESSION_USER‘) session_user,

SYS_CONTEXT(‘USERENV‘, ‘SESSION_USERID‘) session_userid,

SYS_CONTEXT(‘USERENV‘, ‘PROXY_USER‘) proxy_user,

SYS_CONTEXT(‘USERENV‘, ‘PROXY_USERID‘) proxy_userid,

SYS_CONTEXT(‘USERENV‘, ‘DB_DOMAIN‘) db_domain,

SYS_CONTEXT(‘USERENV‘, ‘DB_NAME‘) db_name,

SYS_CONTEXT(‘USERENV‘, ‘HOST‘) host,

SYS_CONTEXT(‘USERENV‘, ‘OS_USER‘) os_user,

SYS_CONTEXT(‘USERENV‘, ‘EXTERNAL_NAME‘) external_name,

SYS_CONTEXT(‘USERENV‘, ‘IP_ADDRESS‘) ip_address,

SYS_CONTEXT(‘USERENV‘, ‘NETWORK_PROTOCOL‘) network_protocol,

SYS_CONTEXT(‘USERENV‘, ‘BG_JOB_ID‘) bg_job_id,

SYS_CONTEXT(‘USERENV‘, ‘FG_JOB_ID‘) fg_job_id,

SYS_CONTEXT(‘USERENV‘, ‘AUTHENTICATION_TYPE‘) authentication_type,

SYS_CONTEXT(‘USERENV‘, ‘AUTHENTICATION_DATA‘) authentication_data

from dual) base

where se.AUDSID = base.sessionid;

原文：http://www.jb51.net/article/58755.htm