SQL challenge to any gurus out there

Question

Hi,
I am trying to create a view which shows inheritence but cannot get this right. I have provided the table and data to assist anyone kind enough to help us plus details of what we are trying to achieve.
CREATE TABLE GLEN_TEST (
TYPE VARCHAR2 (10),
PARENT VARCHAR2 (10),
PROPERTY NUMBER);
INSERT INTO GLEN_TEST ( TYPE, PARENT, PROPERTY ) VALUES ( 'A', NULL, 1);
INSERT INTO GLEN_TEST ( TYPE, PARENT, PROPERTY ) VALUES ( 'A', NULL, 2);
INSERT INTO GLEN_TEST ( TYPE, PARENT, PROPERTY ) VALUES ( 'B', 'A', 3);
INSERT INTO GLEN_TEST ( TYPE, PARENT, PROPERTY ) VALUES ( 'B', 'A', 4);
INSERT INTO GLEN_TEST ( TYPE, PARENT, PROPERTY ) VALUES ( 'C', 'B', 5);
INSERT INTO GLEN_TEST ( TYPE, PARENT, PROPERTY ) VALUES ( 'D', 'B', 6);
COMMIT;
We can see that this is a simple child-parent relationship.
If we do a select * we would get the following result:
TYPE PARENT PROPERTY
A null 1
A null 2
B A 3
B A 4
C B 5
D B 6
What we are trying to achieve would look like this:
TYPE PARENT PROPERTY
A null 1
A null 2
B A 1
B A 2
B null 3
B null 4
C A 1
C A 2
C B 3
C B 4
C null 5
D A 1
D A 2
D B 3
D B 4
D null 6
What we are trying to achieve is for every type to show all it's inheritance i.e. type B inherits from type A because A is it's parent so the properties for type B are 3 and 4 plus the properties for type A which are 1 and 2. Type C would have it's own properties (5) plus those from type B (3,4) which is it's parent plus those of type A (1,2) which is B's parent.
I have tried using the connect by prior but with no success as the inheritence could be n layers deep. If anyone out there likes a challenge and can help - we would be extremely grateful.
Regards
Glen

Answer 1

Ups... a little mistake.
This one works...
SELECT DISTINCT glen_test.type type,
       DECODE(level_type.ty,glen_test.type,'null',level_type.ty) parent,
       level_type.property property
  FROM glen_test,
       (SELECT level lev, type ty, property
      FROM glen_test
     START WITH parent is null
     CONNECT BY PRIOR type = parent) level_type,
       (SELECT level lev, type ty
      FROM glen_test
     START WITH parent is null
     CONNECT BY PRIOR type = parent) level_type_1
WHERE glen_test.type = level_type_1.ty
   AND (level_type.lev < level_type_1.lev
   AND level_type.ty IN (SELECT gl_test.type
                  FROM glen_test gl_test
                  START WITH gl_test.type = level_type_1.ty
                  CONNECT BY PRIOR gl_test.parent = gl_test.type))
   OR (glen_test.type = level_type.ty and level_type.lev = level_type_1.lev);
DC