Re: SQL challenge to any gurus out there

"GlenT" <glen.turner_at_bt.com> wrote in message news:bf8cr9$5sv$1_at_pheidippides.axion.bt.co.uk...
> 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
>

Sounds procedural to me. I suggest you produce a PL/SQL procedure to build and populate a temporary table using the tree walking concepts you've already cosnsidered. Received on Fri Jul 18 2003 - 11:59:49 CEST