Trigger with Condition problem - insert only when not exists

Question

Hello experts!
I have a problem with a trigger I'm trying to create. It compiles but I receive an error message when the trigger fires.
The scenario is as follows:
I have a table TBL_PUNKTDATEN. Whenever the status for a record in that table is changed to 3 or 4 I need the trigger to insert a dataset into my target table (TBL_ARBEIT_ZU_GEBIET).
However, the trigger must only insert data when there's no existing record in the target table. The condition that specifies whether there is a dataset or not, is the field LNG_GEBIET, which exists in the source as well as in the target table. Hence, for each LNG_GEBIET there can be only one dataset in the target table!
I created a trigger using the following code. However it doesn't work.
Maybe you'll see what I want to achieve when having a look at my code.
Can you please help me out on this one?
Thanks a lot!
Sebastian
create or replace
TRIGGER set_status_arbeit_zu_gebiet AFTER
  UPDATE ON TBL_PUNKTDATEN FOR EACH ROW WHEN(new.INT_STATUS=3 or new.INT_STATUS=4)
declare
    cursor c is select LNG_GEBIET from TBL_ARBEIT_ZU_GEBIET where PNUM = 1114 and LNG_GEBIET=:new.LNG_GEBIET;
    x number;
begin
    open c;
    fetch c into x;
    if c%NOTFOUND  then 
    INSERT INTO TBL_ARBEIT_ZU_GEBIET
        LNG_GEBIET,
          LNG_ARBEITSSCHRITT,
          PNUM,
          INT_BEARBEITER,
          DATE_DATUM,
          GEPL_DATUM
        VALUES
        (:new.LNG_GEBIET,
         52,
         1114,
         895,
         sysdate,
         to_date('01.01.1990', 'DD.MM.YYYY')
    end if;
end;Well, on the first insert the code works properly and inserts the recordset as expected. However, if there is an existing recordset where :new.LNG_GEBIET matches LNG_Gebiet in my target table, I receive the ORA-06502 error!
Maybe that spcifies it a little bit???
Hope you can help me!
Thank you!
Edited by: skahlert on 23.09.2009 10:26
Edited by: skahlert on 23.09.2009 10:28

Answer 1

Thank you very much Peter G!
That %Rowtype mod did the trick! Great solution! Thanks! The trigger works principally if there wasn't the fact that it fires also when the status of one individual record is 3 or 4.
I need it to fire only when all records with the same attribute LNG_GEBIET (by the way, you guess was right - it's not a number) are of status 3 or 4.
Is it possible to use the cursor function for the trigger's when condition?
Such as:
declare
    cursor c3 is select COUNT(*) from TBL_PUNKTDATEN where LNG_GEBIET=:new.LNG_GEBIET;and
declare
    cursor c4 is select COUNT(*) from TBL_PUNKTDATEN where INT_STATUS = 3 and  LNG_GEBIET=:new.LNG_GEBIET or INT_STATUS = 4 and  LNG_GEBIET=:new.LNG_GEBIET;
  And then subsequently somehow compare the results of both cursors?
... WHEN c3=c4
declare
    cursor c2 is select LNG_GEBIET from TBL_ARBEIT_ZU_GEBIET where PNUM = 1114 and LNG_GEBIET=:new.LNG_GEBIET;
    v_c2  c2%ROWTYPE;
begin
open c2;
fetch c2 into v_c2;
if c2%notfound then
        INSERT INTO TBL_ARBEIT_ZU_GEBIET
        LNG_GEBIET,
          LNG_ARBEITSSCHRITT,
          PNUM,
          INT_BEARBEITER,
          DATE_DATUM,
          GEPL_DATUM
        VALUES
        (:new.LNG_GEBIET,
         52,
         1114,
         895,
         sysdate,
         to_date('01.01.1990', 'DD.MM.YYYY')
        end if;
        close c2;
end;Please excuse me if the attempt is simply stupid!
Sebastian
Edited by: skahlert on 23.09.2009 15:36
I just saw your reply Max! Thank you! Now I understand far better! Seems to be a successful day! I'm learning a lot! Will also test that method!
If we could find a solution to the problem I described above it would make it a perfect day! I'm continously trying different attempts to have the trigger only fire when all records are 3 or 4.
Not that you think I'm just waiting for your answers! That's not the case!
Thank you all!
Edited by: skahlert on 23.09.2009 17:30