oracle sys_ Context() function

The first parameter is zero 'USERENV', Is constant , The second parameter is also fixed , But it's multiple choice fixed , The optional values are as follows ：

select sys_context('USERENV','AUTHENTICATION_TYPE') from dual;-- User's authentication type

select sys_context('USERENV','AUTHENTICATION_DATA') from dual;-- Unknown

select sys_context('USERENV','BG_JOB_ID') from dual;-- Current assignment id Whether your session is oracle Background program establishment , If not, return to null

select sys_context('USERENV','CLIENT_INFO') from dual;-- adopt dbms_application_info Packages can store up to 64 Bytes of user session information

select sys_context('USERENV','CURRENT_SCHEMA') from dual;-- default schema Will be treated as the current schema. When used in the current session ALTER SESSION SET CURRENT_SCHEMA At the time of statement , Its query return value will be changed

select sys_context('USERENV','CURRENT_SCHEMAID') from dual;-- At present schema Of id

select sys_context('USERENV','CURRENT_USER') from dual;-- Current login user

select REPLACE(SUBSTR(sys_context('USERENV','HOST'),1,30),'\',':') from dual;-- Current session host operating system name

select sys_context('USERENV','CURRENT_USERID') from dual;-- Of the currently logged in user id

select sys_context('USERENV','DB_DOMAIN') from dual;-- Specify initialization parameters for the domain of the database

select sys_context('USERENV','DB_NAME') from dual;-- Database instance name

select sys_context('USERENV','ENTRYID') from dual;-- Available audit identifiers . No more sql Statement . Use USERENV Keyword must be set to AUDIT_TRAIL The initialization parameter of is true .

select sys_context('USERENV','EXTERNAL_NAME') from dual;-- The extension of the database user

select sys_context('USERENV','FG_JOB_ID') from dual;-- Return job id When this session is created by a client process . otherwise , return null

select sys_context('USERENV','INSTANCE') from dual;-- The identifier of the current database instance id

select sys_context('USERENV','ISDBA') from dual;-- Whether the current user is based on dba Identity login

select sys_context('USERENV','LANG') from dual;--iso Yes ‘LANGUAGE’ For short , The parameters of the query are smaller than “LANGUAGE” short

select sys_context('USERENV','LANGUAGE') from dual;-- The result is the storage language used by the current database , The meaning of the query above is the same

select sys_context('USERENV','NETWORK_PROTOCOL') from dual;-- Network protocol for communication

select sys_context('USERENV','NLS_CALENDAR') from dual;-- The current session uses , GMT

select sys_context('USERENV','NLS_CURRENCY') from dual;-- Localized currency symbols , If RMB is ￥, The dollar sign is $

select sys_context('USERENV','NLS_DATE_FORMAT') from dual;-- Current date format , Generally, China is dd-mon-rr

select sys_context('USERENV','NLS_DATE_LANGUAGE') from dual;-- The language of the date , Such as simplified Chinese SIMPLIFIED CHINESE

select sys_context('USERENV','NLS_TERRITORY') from dual;-- The region where the database server is located , Such as China CHINA

select sys_context('USERENV','OS_USER') from dual;-- The user name of the operating system

select sys_context('USERENV','PROXY_USER') from dual;-- Whether to use proxy user . No return null

select sys_context('USERENV','PROXY_USERID') from dual;-- Proxy user id

select sys_context('USERENV','SESSION_USER') from dual;-- The currently authenticated database user name

select sys_context('USERENV','SESSION_USERID') from dual;-- The currently authenticated database user name id

select sys_context('USERENV','SESSIONID') from dual;-- Current session id

select sys_context('USERENV','TERMINAL') from dual;-- Operating system user group

select sys_context('USERENV','IP_ADDRESS') from dual;-- Current session host ip

select sys_context('USERENV','HOST') from dual;-- Current session host operating system name