Getting REF from object

Question

Hi guys !
There is a part of code:
declare
p1 tp_permission; -- my type !
p1_ref ref tp_permission;
begin
select treat(t.p as tp_permission) into p1 from tbl_permissions t where t.p.id = 1; -- OK !!!!!
select ref(p1) into p1_ref from dual; -- here rises
exception !!!
end;
Exception like that:
"inconsistent datatypes: expected TP_PERMISSION got
REF TP_PERMISSION".
Why !? I need in REF.
Thanx in advance.

Answer 1

Dirk, yes, it's clear ...
But difficult is that;
Here my types inheritance:
1.
create or replace type TP_SYS_ABSTRACT_OBJECT as object (
     id                    number,               obj_name          varchar2(1024),      descr               varchar2(1024)
) not final not instantiable
2.
create or replace type TP_PERMISSION3 under TP_SYS_ABSTRACT_OBJECT (
And for polymorphism I create table for storing
all inherited types ...
create table tbl_permissions of TP_SYS_ABSTRACT_OBJECT;
and now i have problem with type casting.
But I found just now !
declare
p1_ref ref tp_permission;
p1 tp_permission;
p2_ref ref tp_sys_abstract_object;
begin
select ref(t) into p2_ref from tbl_permissions3 t where t.id = 1;
select treat(p2_ref as ref tp_permission) into p1_ref from dual;
end;
It's compiled ...
How about it, Dirk ?