How to Correctly Trap PL/SQL Errors for APEX

Question

This is probably a simple fix but, I have been at it for a while and can't seem to find the magic combination.
I have a page process that calls back end PL/SQL. I have a page item that is populated by said PL/SQL procedure, P35_PROCESSING_MSG. As you know the Process allows me to specify a message for Success and another for Failure. My desire is that, if there is a back end failure, the error will display in the dialog area, using the built-in "Process Error Message" functionality. Instead, after execution, the page item still has its default value and the following, ugly, error displays in the tabular report region.
report error:
ORA-20001: Error fetching column value: ORA-01403: no data found
ORA-06510: PL/SQL: unhandled user-defined exceptionI just don't get why it displays here instead of in the usual failure area. Moreover, I don't understand why the error is "*+unhandled+* user-defined exception" when, as you will see, I have handled it.
I have a page process to perfom custom MRD for a tabular form. (I don't think this is really germane to the more generic issue but, I bring it up as an explanaintion for the following code sample). I am diliberately causing a DIVIDE BY ZERO error to test the error handling form the back end.
    PROCEDURE PROCESS_MARGIN_CALL_DELETES( as_StatusMsg OUT VARCHAR2 )  
    IS
        lb_InnerErrorOccured    BOOLEAN := FALSE;
        ln_DeleteTargetCnt      NUMBER := 0;
        ln_DeleteTargetRow      NUMBER := 0;
    BEGIN
        ln_DeleteTargetCnt := apex_application.g_f01.COUNT;       
        FOR ln_DeleteTargetIndx IN 1..ln_DeleteTargetCnt
        LOOP
            ln_DeleteTargetRow := apex_application.g_f01(ln_DeleteTargetIndx);
            BEGIN
                If ( apex_application.g_f14.EXISTS(ln_DeleteTargetRow) ) Then
select 1/0 into ln_DeleteTargetCnt from dual;
                    DELETE FROM RISKDM2.INTRADAY_ECS_RSKALYST_MRGCALL
                    WHERE RISK_MARGCALL_ID = apex_application.g_f14(ln_DeleteTargetRow);
                End If;                     
            EXCEPTION
               WHEN OTHERS THEN
                    as_StatusMsg := as_StatusMsg || SQLERRM;
                    lb_InnerErrorOccured := TRUE;
            END;
        END LOOP;
        If ( lb_InnerErrorOccured = TRUE ) Then
            RAISE INNER_EXCEPTION;    
        Else
            as_StatusMsg := 'Successfully Processed';                  
        End If;
    EXCEPTION
        WHEN INNER_EXCEPTION THEN       
            RAISE_APPLICATION_ERROR( -20001, as_StatusMsg );
        WHEN OTHERS THEN
            as_StatusMsg := as_StatusMsg || SQLERRM;
            RAISE_APPLICATION_ERROR( -20000, as_StatusMsg );
    END; The associated code in APEX is short and sweet:
BEGIN
   MBRDATA.MEMBER_MGR.PROCESS_MARGIN_CALL_DELETES( :P35_PROCESSING_MSG );
EXCEPTION
   WHEN OTHERS THEN
      RAISE_APPLICATION_ERROR( -20002, :P35_PROCESSING_MSG );
END;What I am missing?
-Joe

Answer 1

Joe Upshaw wrote:
This is probably a simple fix but, I have been at it for a while and can't seem to find the magic combination.
I have a page process that calls back end PL/SQL. I have a page item that is populated by said PL/SQL procedure, P35_PROCESSING_MSG. As you know the Process allows me to specify a message for Success and another for Failure. My desire is that, if there is a back end failure, the error will display in the dialog area, using the built-in "Process Error Message" functionality. Instead, after execution, the page item still has its default value and the following, ugly, error displays in the tabular report region.
report error:
ORA-20001: Error fetching column value: ORA-01403: no data found
ORA-06510: PL/SQL: unhandled user-defined exceptionI just don't get why it displays here instead of in the usual failure area. Moreover, I don't understand why the error is "*+unhandled+* user-defined exception" when, as you will see, I have handled it.<Jedi>These are not the errors you are looking for.</Jedi>
Anything included under a "report error" during page rendering is not displaying errors associated with a page process, but with the rendering of that report region, in this case clearly:
ORA-20001: Error fetching column value: ORA-01403: no data foundThe ORA-06510 user-defined exception error relates to this (ORA-20001 being a user-defined error), but it is coming from the APEX framework rather than your code. Often these prove to be untraceable, unrecoverable problems caused by corruption of report metadata, only "fixable" by dropping and recreating the region.
This may or may not be related to the setting of the page item "by said PL/SQL procedure", but the exceptions reported in the region are not being raised by the procedure.
What does the debug trace show to be going on?
Edited by: fac586 on 15-Aug-2012 08:35
Added "...reported in the region..." for clarity