Ich versuche, die folgende Abfrage auszuführen, erhalte jedoch kein Ergebnis.

ann jemand sagen, was ich falsch mach

DECLARE
  object_types VARCHAR2(200);
  v_object_types VARCHAR2(200);
  l_count number;
BEGIN
  object_types :='TABLE,VIEW';
  select ''''||regexp_replace(object_types, '( )*(,)( )*',''',''')||''''  
         into v_object_types from dual;
  dbms_output.put_line(to_char(v_object_types));
  SELECT count(*) into l_count
    FROM all_objects o where o.object_type IN ('||v_object_types||');
  dbms_output.put_line(l_count);

END;