e.g. simple DDL audit trigger

e.g. DDL audit trigger

CREATE TABLE SYSTEM.audit_ddl_history
(
osuser varchar2(50),
session_user varchar2(50),
host varchar2(50),
terminal varchar2(50),
object_owner varchar2(50),
obejct_type varchar2(50),
object_name varchar2(50),
sysevent varchar2(50),
audit_date date
);

CREATE OR REPLACE TRIGGER SYSTEM.ALPERDB_AUDIT_HISTORY
   AFTER DDL
   ON DATABASE
begin
if (ora_sysevent='GRANT')
  then
  NULL; -- don't care to grant!
  else
    insert into SYSTEM.audit_ddl_history(osuser, session_user, host, terminal, object_owner, obejct_type, object_name, sysevent,audit_date)
    values(
      sys_context('USERENV','OS_USER') ,
      sys_context('USERENV','SESSION_USER') , 
      sys_context('USERENV','HOST') , 
      sys_context('USERENV','TERMINAL') ,
      ora_dict_obj_owner,
      ora_dict_obj_type,
      ora_dict_obj_name,
      ora_sysevent,
    sysdate
    );
  end if;
end;
/

e.g.
SQL>
SELECT SYS_CONTEXT ('USERENV', 'SESSION_USER') FROM DUAL;

Ref: https://docs.oracle.com/cd/B10501_01/appdev.920/a96590/adg14evt.htm

SYS_CONTEXT function parameters and examples

Active parameters
ACTION, AUDITED_CURSORID, AUTHENTICATED_IDENTITY, AUTHENTICATION_DATA, AUTHENTICATION_METHOD, BG_JOB_ID, CLIENT_IDENTIFIER, CLIENT_INFO, CURRENT_BIND, CURRENT_SCHEMA, CURRENT_SCHEMAID, CURRENT_SQL, CURRENT_SQLn, CURRENT_SQL_LENGTH, DB_DOMAIN, DB_NAME, DB_UNIQUE_NAME, ENTRYID, ENTERPRISE_IDENTITY, FG_JOB_ID, GLOBAL_CONTEXT_MEMORY, GLOBAL_UID, HOST, IDENTIFICATION_TYPE, INSTANCE, INSTANCE_NAME, IP_ADDRESS, ISDBA, LANG, LANGUAGE, MODULE, NETWORK_PROTOCOL, NLS_CALENDAR, NLS_CURRENCY, NLS_DATE_FORMAT, NLS_DATE_LANGUAGE, NLS_SORT, NLS_TERRITORY, OS_USER, POLICY_INVOKER, PROXY_ENTERPRISE_IDENTITY, PROXY_GLOBAL_UID, PROXY_USER, SERVER_HOST, SERVICE_NAME, SESSION_USER, SESSION_USERID,  SESSIONID, SID, STATEMENTID, TERMINAL

e.g.
SQL> select SYS_CONTEXT ('USERENV', 'SESSION_USER') from dual;
-- HR
e.g.
SQL> select SYS_CONTEXT ('USERENV', 'CURRENT_SCHEMA') from dual;
-- HR

Deprecated parameters
AUTHENTICATION_TYPE, CURRENT_USER, CURRENT_USERID, EXTERNAL_NAME

Extra for sys_context
Link

Ref: http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions165.htm

How to manage logon mechanism with trigger ?

CREATE OR REPLACE TRIGGER SYS.DENY_LOGIN

   AFTER LOGON

   ON DATABASE

BEGIN

   IF     TO_CHAR (SYSDATE, 'hh24') BETWEEN 08 AND 22

      AND SYS_CONTEXT ('USERENV', 'SESSION_USER') = 'HR'

   THEN

      raise_application_error (

         -20001,

         'You cannot login between 08 AM and 06 PM. Please contact with Alper!');

   END IF;

END deny_login;

/

Error message:

ORA-00604: error occurred at recursive SQL level 1

ORA-20001: You cannot login between 08 AM and 06 PM. Please contact with Alper!

ORA-06512: at line 5