说说sys_context函数

ACTION

Identifies the position in the module (application name) and is set through the DBMS_APPLICATION_INFO package or OCI.

SELECT sys_context('USERENV', 'ACTION') FROM dual;

exec dbms_application_info.set_action('INSERTING');

SELECT sys_context('USERENV', 'ACTION') FROM dual;

AUDITED_CURSORID

Returns the cursor ID of the SQL that triggered the audit. This parameter is not valid in a fine-grained auditing environment. If you specify it in such an environment, Oracle Database always returns NULL.

AUTHENTICATED_IDENTITY

Returns the identity used in authentication. In the list that follows, the type of user is followed by the value returned:

• Kerberos-authenticated enterprise user: kerberos principal name
• Kerberos-authenticated external user : kerberos principal name; same as the schema name
• SSL-authenticated enterprise user: the DN in the user's PKI certificate
• SSL-authenticated external user: the DN in the user's PKI certificate
• Password-authenticated enterprise user: nickname; same as the login name
• Password-authenticated database user: the database username; same as the schema name
• OS-authenticated external user: the external operating system user name
• Radius/DCE-authenticated external user: the schema name
• Proxy with DN : Oracle Internet Directory DN of the client
• Proxy with certificate: certificate DN of the client
• Proxy with username: database user name if client is a local database user; nickname if client is an enterprise user
• SYSDBA/SYSOPER using Password File: login name
• SYSDBA/SYSOPER using OS authentication: operating system user name

AUTHENTICATION_DATA

Data being used to authenticate the login user. For X.503 certificate authenticated sessions, this field returns the context of the certificate in HEX2 format.

Note: You can change the return value of the AUTHENTICATION_DATA attribute using the length parameter of the syntax. Values of up to 4000 are accepted. This is the only attribute of USERENV for which Oracle implements such a change.

AUTHENTICATION_METHOD

Returns the method of authentication. In the list that follows, the type of user is followed by the method returned.

• Password-authenticated enterprise user, local database user, or SYSDBA/SYSOPER using Password File; proxy with username using password: PASSWORD
• Kerberos-authenticated enterprise or external user: KERBEROS
• SSL-authenticated enterprise or external user: SSL
• Radius-authenticated external user: RADIUS
• OS-authenticated external user or SYSDBA/SYSOPER: OS
• DCE-authenticated external user: DCE
• Proxy with certificate, DN, or username without using password: NONE

BG_JOB_ID

Job ID of the current session if it was established by an Oracle background process. Null if the session was not established by a background process.

CLIENT_IDENTIFIER

Returns an identifier that is set by the application through the DBMS_SESSION.SET_IDENTIFIER procedure, the OCI attribute OCI_ATTR_CLIENT_IDENTIFIER, or the Java class Oracle.jdbc.OracleConnection.setClientIdentifier. This attribute is used by various database components to identify lightweight application users who authenticate as the same user.

SELECT sys_context('USERENV', 'CLIENT_IDENTIFIER') FROM dual;

exec dbms_session.set_identifier(USER || ' ' || SYSTIMESTAMP);

SELECT sys_context('USERENV', 'CLIENT_IDENTIFIER') FROM dual;

CLIENT_INFO

Returns user session information that can be stored by an application using the DBMS_APPLICATION_INFO package.

SELECT sys_context('USERENV', 'CLIENT_INFO') FROM dual;

exec dbms_application_info.set_client_info('TEST');

SELECT sys_context('USERENV', 'CLIENT_INFO') FROM dual;

CURRENT_BIND

The bind variables for fine-grained auditing

CURRENT_EDITION_ID

The name of the current edition

SELECT sys_context('USERENV', 'CURRENT_EDITION_ID') FROM dual;

CURRENT_EDITION_NAME

The name of the current edition

SELECT sys_context('USERENV', 'CURRENT_EDITION_NAME') FROM dual;

CURRENT_SCHEMA

Name of the default schema being used in the current schema. This value can be changed during the session with an ALTER SESSION SET CURRENT_SCHEMA statement.

SELECT sys_context('USERENV', 'CURRENT_SCHEMA') FROM dual;

CURRENT_SCHEMAID

Identifier of the default schema being used in the current session.

SELECT sys_context('USERENV', 'CURRENT_SCHEMAID') FROM dual;

SELECT user#
FROM sys.user$
WHERE name = USER;

CURRENT_SQL

Returns the first 4K bytes of the current SQL that triggered the fine-grained auditing event.

CURRENT_SQLn

CURRENT_SQLn attributes return subsequent 4K-byte increments, where n can be an integer from 1 to 7, inclusive. CURRENT_SQL1 returns bytes 4K to 8K; CURRENT_SQL2 returns bytes 8K to 12K, and so forth. You can specify these attributes only inside the event handler for the fine-grained auditing feature.

CURRENT_SQL_LENGTH

The length of the current SQL statement that triggers fine-grained audit or row-level security (RLS) policy functions or event handlers. Valid only inside the function or event handler.

DB_DOMAIN

Domain of the database as specified in the DB_DOMAIN initialization parameter.

SELECT sys_context('USERENV', 'DB_DOMAIN') FROM dual;

DB_NAME

Name of the database as specified in the DB_NAME initialization parameter.

SELECT sys_context('USERENV', 'DB_NAME') FROM dual;

SELECT name, value
FROM gv$parameter
where name LIKE 'db%name';

DB_UNIQUE NAME

Name of the database as specified in the DB_UNIQUE_NAME initialization parameter.

SELECT sys_context('USERENV', 'DB_UNIQUE_NAME') FROM dual;

SELECT name, value
FROM gv$parameter
where name LIKE 'db%name';

ENTRYID

The available auditing entry identifier. You cannot use this option in distributed SQL statements. To use this keyword in USERENV, the initialization parameter AUDIT_TRAIL must be set to true.

ENTERPRISE_IDENTITY

Returns the user's enterprise-wide identity:

• For enterprise users: the Oracle Internet Directory DN.
• For external users: the external identity (Kerberos principal name, Radius and DCE schema names, OS user name, Certificate DN).
• For local users and SYSDBA/SYSOPER logins: NULL.

The value of the attribute differs by proxy method:

• For a proxy with DN: the Oracle Internet Directory DN of the client
• For a proxy with certificate: the certificate DN of the client for external users; the Oracle Internet Directory DN for global users
• For a proxy with username: the Oracle Internet Directory DN if the client is an enterprise users; NULL if the client is a local database user.

FG_JOB_ID

Job ID of the current session if it was established by a client foreground process. Null if the session was not established by a foreground process.

GLOBAL_CONTEXT_MEMORY

The number used in the System Global Area by the globally accessed context.

SELECT sys_context('USERENV', 'GLOBAL_CONTEXT_MEMORY') FROM dual;

GLOBAL_UID

Returns the global user ID from Oracle Internet Directory for Enterprise User Security (EUS) logins; returns null for all other logins.

HOST

Name of the host machine from which the client has connected.

SELECT sys_context('USERENV', 'HOST') FROM dual;

IDENTIFICATION_TYPE

Returns the way the user's schema was created in the database. Specifically, it reflects the IDENTIFIED clause in the CREATE/ALTER USER syntax. In the list that follows, the syntax used during schema creation is followed by the identification type returned:

• IDENTIFIED BY password: LOCAL
• IDENTIFIED EXTERNALLY: EXTERNAL
• IDENTIFIED GLOBALLY: GLOBAL SHARED
• IDENTIFIED GLOBALLY AS DN: GLOBAL PRIVATE

SELECT sys_context('USERENV', 'IDENTIFICATION_TYPE') FROM dual;

INSTANCE

The instance identification number of the current instance.

SELECT sys_context('USERENV', 'INSTANCE') FROM dual;

INSTANCE_NAME

The name of the instance.

SELECT sys_context('USERENV', 'INSTANCE_NAME') FROM dual;

IP_ADDRESS

IP address of the machine from which the client is connected.

ISDBA

TRUE if the session is SYS

SELECT sys_context('USERENV', 'ISDBA') FROM dual;

LANG

The ISO abbreviation for the language name, a shorter form. than the existing 'LANGUAGE' parameter.

SELECT sys_context('USERENV', 'LANG') FROM dual;

LANGUAGE

The language and territory currently used by your session, along with the database character set, in the form.:

language_territory.characterset.

SELECT sys_context('USERENV', 'LANGUAGE') FROM dual;

MODULE

The application name (module) set through the DBMS_APPLICATION_INFO package or OCI.

SELECT sys_context('USERENV', 'MODULE') FROM dual;

NETWORK_PROTOCOL

Network protocol being used for communication, as specified in the 'PROTOCOL=protocol' portion of the connect string.

NLS_CALENDAR

The current calendar of the current session.

SELECT sys_context('USERENV', 'NLS_CALENDAR') FROM dual;

NLS_CURRENCY

The currency of the current session.

SELECT sys_context('USERENV', 'NLS_CURRENCY') FROM dual;

NLS_DATE_FORMAT

The date format for the session.

SELECT sys_context('USERENV', 'NLS_DATE_FORMAT') FROM dual;

NLS_DATE_LANGUAGE

The language used for expressing dates.

SELECT sys_context('USERENV', 'NLS_DATE_LANGUAGE') FROM dual;

NLS_SORT

BINARY or the linguistic sort basis.

SELECT sys_context('USERENV', 'NLS_SORT') FROM dual;

NLS_TERRITORY

The territory of the current session.

SELECT sys_context('USERENV', 'NLS_TERRITORY') FROM dual;

OS_USER

Operating system username of the client process that initiated the database session.

SELECT sys_context('USERENV', 'OS_USER') FROM dual;

POLICY_INVOKER

The invoker of row-level security (RLS) policy functions.

PROXY_ENTERPRISE_IDENTITY

Returns the Oracle Internet Directory DN when the proxy user is an enterprise user.

PROXY_GLOBAL_UID

Returns the global user ID from Oracle Internet Directory for Enterprise User Security (EUS) proxy users; returns NULL for all other proxy users.

PROXY_USER

Name of the database user who opened the current session on behalf of SESSION_USER.

PROXY_USERID

Identifier of the database user who opened the current session on behalf of SESSION_USER.

SERVER_HOST

The host name of the machine on which the instance is running.

SELECT sys_context('USERENV', 'SERVER_HOST') FROM dual;

SERVICE_NAME

The name of the service to which a given session is connected.

SELECT sys_context('USERENV', 'SERVICE_NAME') FROM dual;

SESSION_USER

Database user name by which the current user is authenticated. This value remains the same throughout the duration of the session.

SELECT sys_context('USERENV', 'SESSION_USER') FROM dual;

SESSION_USERID

Identifier of the database user name by which the current user is authenticated.

SELECT sys_context('USERENV', 'SESSION_USERID') FROM dual;

SESSIONID

The auditing session identifier. You cannot use this option in distributed SQL statements. This is the equivalent to the AUDSID column in gv$session.

SELECT sys_context('USERENV', 'SESSIONID') FROM dual;

SID

The session number (different from the session ID).

SELECT sys_context('USERENV', 'SID') FROM dual;

STATEMENTID

The auditing statement identifier. STATEMENTID represents the number of SQL statements audited in a given session.

TERMINAL

The operating system identifier for the client of the current session. In distributed SQL statements, this option returns the identifier for your local session. In a distributed environment, this is supported only for remote SELECT statements, not for remote INSERT, UPDATE, or DELETE operations. (The return length of this parameter may vary by operating system.)

SELECT sys_context('USERENV', 'TERMINAL') FROM dual;