Return statment for dynamic LOV - exception handling

Question

Hello All,
Good Morning.
Oracle 11g, apex 3.2.1
I am having an dynamic LOV with a return statement.
code :-
==========================
declare
owner varchar2(12) :='';
stmt varchar2(4000) :='';
No_Records_Exception exception ;
phase varchar2(30);
year varchar2(30);
month_quarter varchar2(30);
begin
stmt :='select distinct famid d, famid r from '
||:P1_SCHEMA||'.'||'FMLY';
return stmt;
exception
when No_Records_Exception then
raise_application_error (-20998 , ' Schema does not exist ' );
when OTHERS then
raise_application_error (-20999,' Select the schema first ' );
end;
===================
My question is - why the exception is not handled when there are no table found.
Am getting the following errr ..
Error: ORA-06550: line 1, column 120: PL/SQL: ORA-00903: invalid table name ORA-06550: line 1, column 7: PL/SQL: SQL Statement ignored performing List of Values query: "select distinct famid d, famid r from .FMLY".
Pls let me know how to handle this error.. if the table is invalid.
scenario for poping this error:-
==================
I am having three "select list with redirect" items and one radio group ( having two Radion buttons - Relation , Famid )
The requirement is when the user selects Famid radio then the lov is suppose to populate the multiselect list with famid values from table P2D2008M05.FMLY and the schema P2D2008M05 is selected from three list items
P2D, 2008 , M05 one from each item .
If the schema is not selected and the user selects radio famid , then the error is coming , I need to put a validation or error handling mechanism when in which ,if the user selects famid radio and the schema is not selected , I need to raise an exception with proper error message to the user saying that the schema is not selected.
Pls helpin this regard.
Thanks/kumar.

Answer 1

Hi,
Your exception is for function that return select.
Error is raised when Apex procedures try use select your function returns.
You need test your select inside function or create validations
Your function could look something like this
DECLARE
  stmt    VARCHAR2(4000);
  l_count NUMBER;
BEGIN
  IF NVL(:P1_SCHEMA,'%'||'null%') = '%'||'null%' THEN
    raise_application_error (-20999,' Select the schema first ' );
  END IF;
  SELECT COUNT(1) INTO l_count FROM all_users WHERE username = :P1_SCHEMA ;
  IF l_count = 0 THEN
    raise_application_error (-20998 , ' Schema does not exist ' );
  END IF;
  stmt :='select distinct famid d, famid r from ' ||:P1_SCHEMA ||'.' ||'FMLY';
  RETURN stmt;
END;That is just example, I did not test it. And I think it is not good idea raise errors inside LOV function.
You should use Apex after submit validations
Br,Jari