How to display a logon message using login trigger?

Question

Hello,
I have created a logon trigger similar to Tom's guide in his thread - http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:3236035522926. The guideline in the thread disables a user login, but I need the trigger to prompt a message that the logon schema has been changed to XYZ schema. Trying to use the same code format, I am able to publish the message, but at the end the connection is getting disconnected similar to Tom's example:
ops$[email protected]>
ops$[email protected]>
ops$[email protected]> connect scott/tiger
ERROR:
ORA-00604: error occurred at recursive SQL level 1
ORA-20001: You are not allowed to logon from this terminal!!!
ORA-06512: at line 7
Warning: You are no longer connected to ORACLE.
ops$[email protected]> connect /
Connected.I want the user to establish a session after login and still prompt the message. How can do that?
The trigger I am trying is -
CREATE OR REPLACE TRIGGER ABC_DBA.USER_LOGON
after logon on database
DISABLE
declare
v_user varchar2(30);
v_base_user varchar2(30);
begin
select SYS_CONTEXT ('USERENV', 'SESSION_USER') into v_user from dual;
dbms_output.enable;
dbms_output.put_line(v_user);
execute immediate 'alter session set current_schema=XYZ';
-- RAISE_APPLICATION_ERROR (-20001, 'Welcome');
end;Thanks in advance
aBBy
PS: Forgot to mention - this is a 11gR2 RAC on Linux env.
Edited by: AB007 on Oct 12, 2012 11:29 AM

Answer 1

After user is logged in without an error, the Oracle Client does not expect any message from DB.
It is up to Client Application to expect such a message.
For example if the Client Application is SQL*Plus, you can issue
SET SERVEROUTPUT ON
After that SQL*Plus will read from DBMS_OUTPUT buffer and print on the screen.
Others applications have to be programmed to do similar.