Triggers and message

Question

Hi,
Is it possible to create a message inside a trigger and showing?
Regards
Jomar

Answer 1

I would like to prompt simple alerts ... ou a memo.If this is for viewing in SQL*Plus then you can use DBMS_OUTPUT....
SQL> create or replace trigger emp_i_br before insert on emp for each row
  2  begin
  3      if :new.empno  is null then
  4          select emp_seq.nextval into :new.empno  from dual;
  5      end if;
  6     if :new.sal is null then
  7         dbms_output.put_line(:new.empno||'::'||:new.ename||' has no salary!');
  8      end if;
  9  end;
10  /
Trigger created.
SQL> insert into emp (empno, ename, deptno)
  2  values
  3  (109, 'JOMAR', 30)
  4  /
109::JOMAR has no salary!
1 row created.
SQL> For more sophisticated usages there is DBMS_ALERT, UTL_FILE, UTL_SMTP/UTL_MAIL, etc. It rather depends on what it is you want to do.
On the whole I would prefer to have such communications in the UI layer of the app rather than in the database, especially in triggers. If the INSERT operation is being initiated by a batch PL/SQL program who is there to read all those messages?
Oh, and as a user I find messages such as "Operation succesfully completed" extremely annoying. The successful completion of every operation should be the default state. Only tell me when the operation fails.
Cheers, APC
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