Understanding how Error handling works in transformation

Question

Hi Experts,
I am trying to achieve error handling in Start and End Routine by writing the error log to the monitor and also raising the exception in case a match is not found.
I understand the code below achieves what I am looking for, but I want to know how this works
  if sy-subrc ne 0.
        monitor_rec-msgid = 'BI'.
        monitor_rec-msgty = 'E'.
        monitor_rec-msgno = '001'.
        monitor_rec-msgv1 = 'No entry for ZTYPE in source '.
        monitor_rec-msgv2 =  .
        append monitor_rec to MONITOR.
        raise exception type CX_RSROUT_ABORT.
      endif.
Can someone please explain how the above code works?
I am not sure how these messages get written to the monitor and how to check these error records. Also if a load is scheduled in the process chains, does the DTP error log show the exception CX_RSROUT_ABORT?

Answer 1

proper exception handling is one of the most important thing to consider in your pl/sql code.
One basic principle is to trap/handle only those exceptions that you expect. In general this means you should NOT use the when other execption (only at the outermost call structure)
I guess this is oracle FORMS pl/sql, so we have to be careful with some assupmtions.
But this should work. See also how indenting the ode helps to improve readability. Here in the forum you need to use {<b></b>code} tages before and after your code to preserve indention and to enable basic highlighting
untested
/* fetch the primary account */
begin
   select customer_code into cust from primary_account where pc.customer_code=:import_can.consignee_code;
exception
   when no_data_found then
      j:='Customer ('||:import_can.consignee_code||') not found. Account is not created for this consignee ';
      raise_application_error(-20001,j); /* might be raise form_trigger_error here or something like that */
   when too_many_rows then
      j:='Customer ('||:import_can.consignee_code||') has several Accounts!';
      raise_application_error(-20001,j);
end;
begin
     select customer_code into cust from cust_details where customer_code=:import_can.consignee_code;
exception
    when no_data_found then
        h:='consignee_code is not exist in customer code';
       raise_application_error(-20001,h);
end;
COMMIT_FORM;
:GLOBAL.ADDCAN:=0;
SA:=SHOW_ALERT('SAVE');
ENAB;