dereferencing nested objects

Hi,

I am quite new to object-relational databases. This is how the object Types look like:

CREATE OR REPLACE TYPE port_typ AS OBJECT( device_id NUMBER,
portnummer NUMBER
);
CREATE OR REPLACE TYPE port_tab_typ AS OBJECT( port port_typ,
gegenport REF port_tab_typ
);

I built an object table of type "port_tab_typ" and inserted some rows.
> Select port , DEREF(gegenport) from ports
behaves just as it should do I get:

PORT:                            DEREF(gegenport)
PORT_TYP(33,1)          PORT_TAB_TYP(PORT_TYP(30,2))

How can I use the device_id (30) of the object port_typ in Port_tab_typ for e.g. a where-clause?
I want to get all rows that are referenced by gegenport AND have a device_id of 30.

I hope i was able to explain it clear I not too familiar with this object stuff.

Thanks in advance
Thomas Received on Mon Oct 08 2001 - 04:05:29 CDT