Query for spesific children in a tree structure

Question

Hi,
My data is organized in a tree structure.
I need a sql statement that returns a parent that
have a set of children corresponding to some demands.
I provide a very simplified description of my data, but it covers my problem.
Can anyone please help me write a select statement that gives me all featureids
that have a GID attribute with children GNR=123 AND BNR=456?
Regards
gv
create table attributetype( id number, name varchar2(8), parentid number );
insert into attributetype( id, name ) values ( 1, 'GIDLIST' );
insert into attributetype( id, name, parentid ) values ( 2, 'GID', 1 );
insert into attributetype( id, name, parentid ) values( 3, 'GNR', 2 );
insert into attributetype( id, name, parentid ) values ( 4, 'BNR', 2 );
create table attribute( featureid number, id number, parentid number, atttypeid number, intvalue number );
--attributes for feature1
insert into attribute( featureid, id, parentid, atttypeid ) values( 1, 1, 0, 1 );
insert into attribute( featureid, id, parentid, atttypeid ) values( 1, 2, 1, 2 );
insert into attribute( featureid, id, parentid, atttypeid, intvalue ) values( 1, 3, 2, 3, 123 );
insert into attribute( featureid, id, parentid, atttypeid, intvalue ) values( 1, 4, 2, 4, 456 );
insert into attribute( featureid, id, parentid, atttypeid ) values( 1, 5, 1, 2 );
insert into attribute( featureid, id, parentid, atttypeid, intvalue ) values( 1, 6, 5, 3, 12 );
insert into attribute( featureid, id, parentid, atttypeid, intvalue ) values( 1, 7, 5, 4, 456 );
--attributes for feature 2
insert into attribute( featureid, id, parentid, atttypeid ) values( 2, 8, 0, 1 );
insert into attribute( featureid, id, parentid, atttypeid ) values( 2, 9, 8, 2 );
insert into attribute( featureid, id, parentid, atttypeid, intvalue ) values( 2, 10, 9, 3, 678 );
insert into attribute( featureid, id, parentid, atttypeid, intvalue ) values( 2, 11, 9, 4, 456 );
insert into attribute( featureid, id, parentid, atttypeid ) values( 2, 12, 8, 2 );
insert into attribute( featureid, id, parentid, atttypeid, intvalue ) values( 2, 13, 12, 3, 876 );
insert into attribute( featureid, id, parentid, atttypeid, intvalue ) values( 2, 14, 12, 4, 456 );
commit;
column name format a15
select a.featureid featureid, lpad(' ', (level - 1) * 2) || b.name name, a.id attid, a.parentid parentid, a.intvalue
from attribute a, attributetype b
where a.atttypeid=b.id
connect by prior a.id=a.parentid
start with a.parentid=0;
FEATUREID NAME ATTID PARENTID INTVALUE
1 GIDLIST 1 0
1 GID 2 1
1 GNR 3 2 123
1 BNR 4 2 456
1 GID 5 1
1 GNR 6 5 12
1 BNR 7 5 456
2 GIDLIST 8 0
2 GID 12 8
2 GNR 13 12 876
2 BNR 14 12 456
2 GID 9 8
2 GNR 10 9 678
2 BNR 11 9 456

Answer 1

Hi,
Thanks for providing the CREATE TABLE and INSERT statements; that helps a lot.
You want featureids that meet three criteria:
(1) there is a GID attribute
(2) the GID attribute has a GNR child with intvalue=123
(3) the GID attribute has a BNR child with intvalue=456
Since you're looking for immediate children, not distant descendants, it's easiest to do this with a non-hierarrchical query that finds one of these criteria, and does EXISTS sub-queries to test for the other two.
For example:
WITH aat AS
( -- Begin aat: join of attribute and attributetype
     SELECT     a.featureid
     ,     a.id
     ,     a.parentid
     ,     a.intvalue
     ,     t.name
     FROM     attribute     a
     JOIN     attributetype     t     ON     a.atttypeid     = t.id
) -- End aat: join of attribute and attributetype
SELECT DISTINCT     featureid
FROM     aat     m     -- m for main
WHERE     name     = 'GID'
AND     EXISTS     (     -- Begin EXISTS sub-query for GNR=123
          SELECT     NULL
          FROM     aat
          WHERE     parentid     = m.id
          AND     name          = 'GNR'
          AND     intvalue     = 123
          )     -- End EXISTS sub-query for GNR=123
AND     EXISTS     (     -- Begin EXISTS sub-query for BNR=456
          SELECT     NULL
          FROM     aat
          WHERE     parentid     = m.id
          AND     name          = 'BNR'
          AND     intvalue     = 456
          )     -- End EXISTS sub-query for BNR=456
;Alternatively, you could do a three-way self join, and skip the EXISTS sub-queries.
If you were looking for GNR and BNR descendants, any number of levels below the same GID node, it's easy to modify the query above. Just re-write the EXISTS sub-queries to CONNECT BY queries that "START WITH parentid = m.id".
It looks like this application will have a lot of use for a view like aat, above. If you don't already have a permanent view like that, you should create one.