Trigger - find triggering statement

Question

Heyho there,
I have a question: can a trigger somehow find out, which statement caused the trigger to fire? And if so, is it possible to find out the session?
thx for your help in advance
René

Answer 1

Hello
Within a trigger, you can access the session id via SYS_CONETEXT('USERENV','SESSIONID') - that will give you the audsid value that you'd find in v$session.audsid. You could use this to query v$session if you wanted to get sid and serial#.
In terms of finding out which statement caused the trigger to fire, that's a little more difficult. The issue is that the statement could have been as a result of someone connecting via a development tool and issuing a dml statement, or it could be as a result of calling a stored procedure. When it's the result of a procedure call, you could find the caller details like so
X>create table dt_test
  2  (id number)
  3  /
Table created.
Elapsed: 00:00:01.09
X>create or replace trigger dt_test_trg
  2  before insert or update on dt_test
  3  for each row
  4  declare
  5
  6      v_Owner         VARCHAR2(30);
  7      v_Name          VARCHAR2(30);
  8      v_Line          NUMBER;
  9      v_Caller        VARCHAR2(30);
10
11  BEGIN
12
13      owa_util.who_called_me
14      (   v_Owner ,
15          v_Name  ,
16          v_Line  ,
17          v_Caller
18      );
19
20      dbms_output.put_line('Owner '||v_Owner);
21      dbms_output.put_line('Name '||v_Name);
22      dbms_output.put_line('Line '||v_Line);
23      dbms_output.put_line('Caller '||v_Caller);
24
25
26  end;
27  /
Trigger created.
Elapsed: 00:00:00.57
X>create or replace procedure p_test
  2  is
  3
  4  begin
  5
  6      insert into dt_test values(1);
  7
  8  end;
  9  /
Procedure created.
Elapsed: 00:00:00.35
X>set serveroutput on
X>
X>ev_ec p_test;
Owner SWAPP_OWNER
Name P_TEST
Line 6
Caller PROCEDURE
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.25But note that if it is a package that contains the stored procedure, you'll get the line number and the name of the package, not the name of the procedure...
X>create or replace package pkg_test
  2  is
  3
  4      procedure p_test;
  5
  6  end;
  7  /
Package created.
Elapsed: 00:00:00.07
X>
X>create or replace package body pkg_test
  2  is
  3
  4      procedure p_test
  5      is
  6
  7      begin
  8
  9          insert into dt_test values(1);
10
11      end;
12  end;
13  /
Package body created.
Elapsed: 00:00:00.10
X>exec pkg_test.p_test;
Owner SWAPP_OWNER
Name PKG_TEST
Line 9
Caller PACKAGE BODYand if this is just a stand alone SQL statement that's not being called from a stored procedure, you won't get any caller info...
X>insert into dt_test values(1);
Owner
Name
Line
Caller
1 row created.
Elapsed: 00:00:00.00Hope that helps
David
Edited by: 950453 on Sep 10, 2012 10:37 AM
Just saw the link to the solution that searches the shared pool for the triggering statement which will give a much more detailed view of what's caused the statement to fire. Bravo.