SELECT OID FROM clause not working

Question

The following statements gets ORA-00904: "OID": invalid identifier.
The SELECT OID FROM clause is intended to pull in a REF to the MANAGER with MGR_ID= 000001.
Oracle seems to think there are no OIDs for the entries in the MANAGERS table.
INSERT INTO STORES VALUES (
100001,
ADDRESS(888, 'Main_Street', 'Rancho_Alegre', 'CA', '94049'),
COF_ARRAY('Colombian', 'French_Roast', 'Espresso', 'Colombian_Decaf', 'French_Roast_Decaf'),
(SELECT OID FROM MANAGERS WHERE MGR_ID = 000001)
Here is how the MANAGER, MANAGERS, ans STORES were defined.
CREATE TYPE MANAGER AS OBJECT (
MGR_ID INTEGER,
LAST_NAME VARCHAR(40),
FIRST_NAME VARCHAR(40),
PHONE char(10)
CREATE TABLE MANAGERS OF MANAGER OBJECT IDENTIFIER IS SYSTEM GENERATED;
CREATE TABLE STORES (
STORE_NO INTEGER,
LOCATION ADDRESS,
COF_TYPES COF_ARRAY,
MGR REF MANAGER
My questions:
1. I don't see any OIDs when I display the MANAGERS table with the Object Browser. That is normal it isn't it? Aren't they always hidden?
2. Can anyone tell me what I am doing wrong?

Answer 1

[Documentation Says....|http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28371/adobjdes.htm]
The object identifier column is a hidden column that Oracle uses to construct references to the row objects. *Oracle provides no access to the internal structure of object identifiers*. This structure can change at any time. Applications are only concerned with using object references for fetching and navigating objects.
In the above mentioned link is a link to what i think you're attempting...
http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28371/adobjint.htm#i458258