REF to an object in a relational table

Question

Hi!
I try do create a DB for TINs made of triangles. Because of the topology a triangles ist made of three edges and each edge is made of two nodes. The nodes contain the geometry (x,y,z coordinates).
I created object types for each element.
In order to fasten the request of geometry data I build Spatial objects, too.
My tables look like the following
CREATE OR REPLACE TYPE node_objtyp AS OBJECT (
node_Id NUMBER(10,0),
xValue NUMBER(7,3),
yValue NUMBER(7,3),
zValue NUMBER(7,3)
CREATE TABLE nodes_reltab(
node_Id NUMBER(10,0),
node_Ref node_objtyp,
node_Shape mdsys.sdo_geometry
CREATE OR REPLACE TYPE edge_objtyp AS OBJECT (
edge_Id NUMBER(10,0),
from_Node_Ref REF node_objtyp,
to_Node_Ref REF node_objtyp,
is_Fold     NUMBER(1,0)
CREATE TABLE edges_reltab(
edge_Id NUMBER(10,0),
edge_Ref edge_objtyp,
edge_Shape mdsys.sdo_geometry
How do I insert data into edges_reltab if from_Node_Ref and to_Node_Ref in edge_objtyp should refer to two existing node_objtyps in nodes_reltab node_Ref column??
I tried
INSERT INTO edges_reltab VALUES(
1,
edge_objtyp(
1,
(SELECT REF(n)
FROM (
SELECT node_ref
FROM nodes_reltab
WHERE node_Id = 1
)n
(SELECT REF(n)
FROM (
SELECT node_ref
FROM nodes_reltab
WHERE node_Id = 2
)n
0
mdsys.sdo_geometry(
3002,
NULL,
NULL,
mdsys.sdo_elem_info_array(1,2,1),
mdsys.sdo_ordinate_array(
2,4,0,
3,4,0,
2,4,0
But just got a ORA-00904 error!
In my first DB I used object tables. It worked fine, but it was impossible to create an Spatial index an these tables. So I've been forced to use relational tables.
Thank you for your help!
Joerg

Answer 1

Hi Joerg
It is only possible to use REF with object tables and object views.
Creating an object view over the relational table will probably not solve your problem (see error ORA-22979).
Therefore, since you are using a relational model, you should use a foreign key.
Chris