The purpose is to send extra information to triggers like current user id from a web application. Since a connection pool is used, and same user id is used for all connections how do I pass the original web user id to trigger? This I need to implement without touching application code. It is a java based application.
John
You can use the client_identifier session variable to pass an application user to a trigger.
Set it after connecting to the database like this:
CALL dbms_session.set_identifier('<<username>>');
and retrieve it inside the trigger:
SELECT sys_context('USERENV','CLIENT_IDENTIFIER') INTO username FROM DUAL;
More info can be found in the Oracle docs
you could use Oracle Contexts:
SQL> CREATE OR REPLACE PACKAGE test_pkg AS
2 PROCEDURE set_context(p_attribute VARCHAR2, p_value VARCHAR2);
3 END test_pkg;
4 /
Package created
SQL> CREATE OR REPLACE PACKAGE BODY test_pkg AS
2 PROCEDURE set_context(p_attribute VARCHAR2, p_value VARCHAR2) IS
3 BEGIN
4 dbms_session.set_context('test_ctx', p_attribute, p_value);
5 END;
6 END test_pkg;
7 /
Package body created
SQL> create context test_ctx using test_pkg;
Context created
SQL> exec test_pkg.set_context ('user_id', 'Vincent');
PL/SQL procedure successfully completed
SQL> select sys_context('test_ctx', 'user_id') from dual;
SYS_CONTEXT('TEST_CTX','USER_I
--------------------------------------------------------------------------------
Vincent
You can use a package to keep track of the web user:
create package web_user_pkg is
procedure set_username (p_username varchar2);
function username return varchar2;
end;
create package body web_user_pkg is
g_username varchar2(30);
procedure set_username (p_username varchar2)
is
begin
g_username := p_username;
end;
function username return varchar2 is
begin
return g_username;
end;
end;
In the web page call web_user_pkg.set_username with the current user's ID before performing any DML or other package calls.
In the trigger use web_user_pkg.username to get the web user name.
