日常我们可能需要限制一些客户端或者IP 访问某个用户

则可以通过trigger的方式实现

1.trigger内容

这边通过建立一个Trigger来限制登陆

CREATE OR REPLACE TRIGGER global_logon_trg AFTER logon ON DATABASE

DECLARE

p_session_user varchar2(64);

p_ip varchar2(64);

BEGIN

SELECT UPPER(SYS_CONTEXT('USERENV', 'SESSION_USER')) INTO p_session_user FROM DUAL;

SELECT UPPER(SYS_CONTEXT('USERENV', 'IP_ADDRESS')) INTO p_ip FROM DUAL;

DBMS_SESSION.SET_IDENTIFIER(p_session_user || '-' || p_ip);

IF ((p_session_user = 'FWASSY') AND (p_ip IN ('10.65.5.189'))) THEN

DBMS_SESSION.SET_IDENTIFIER('about to raise app_error..');

RAISE_APPLICATION_ERROR(-20003,'You are not allowed to connect to the database');

END IF;

END;

/

2. SYS_CONTEXT

如下为一些可用的参数，大家可以根据需求来进行指定

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,

from dual ;

3.注意事项

该trigger对sys用户不生效

对具有dba权限的用户不生效