Tricky query with multiple hierarchial sub queries

Question

Here's a pussle that I cannot solve. Who can help me?
Given table F (records form a binary tree with levels 0, 1, and
2):
Id IdParent
F1 null
F2 F1
F3 F2
F4 F2
F5 F1
F6 F5
F7 F5
and given table D (records form a similar binary tree with
levels 0, 1, and 2):
Id IdParent
D1 null
D2 D1
D3 D2
D4 D2
D5 D1
D6 D5
D7 D5
and given table P (cross referencing tables F and D):
IdF IdD
F2 D6
F3 D2
F5 D7
and given table S (which holds the seed to the query):
IdF
F3
and given table I (just any collection of records that reference
table D which we want to select records from):
Id IdD
I1 D1
I2 D2
I3 D3
I4 D4
I5 D5
I6 D6
I7 D7
I8 D1
I9 D5
all together being related like in figure 1:
S.IdF =>> F.Id
F.Id <- P.IdF
P.IdD -> D.Id
D.Id <<= I.IdD
where =>> denotes 'is or is a descenden of'
and -> denotes 'is'
I want to build a query that lets me select all records from
table I, which reference table D, such that the referenced
records in table D are hierarchial descendents of any record
that is referenced by records in table P, for which they
reference records in table F, which are ancestors to records
referenced by records in table S.
If it wasn't for the hierarchial approach on both sides of the
cross referencing table, matters would have been easy. Then the
releational map would have been like in figure 2:
S.IdF <- P.IdF
P.IdD -> I.IdD
and the query would have been:
SELECT I.Id
FROM I, P, S
WHERE I.IdD = P.IdD
AND P.IdF = S.IdF
So in what I am looking for, you may say that the '='-signs in
this select statement should denote 'is or is a descenden of'
going towards the side of table P.
Given the tables listed above and given the query I am seeking,
I expect to retrieve the following result set:
I.Id
I2
I3
I4
I6
Tricky, eh? I belive the figures are the best angles to
understand this problem.

Answer 1

You do this with subqueries and hierarchical queries...
First the hierarchal subquery on F...
SQL> SELECT f.id
  2    FROM f
  3   CONNECT BY PRIOR f.idp = f.id
  4   START WITH f.id IN ( SELECT idf FROM s )
  5       ;
ID
F3
F2
F1
Then join with the cross reference table...
SQL> SELECT p.idd
  2    FROM p
  3       , (  SELECT f.id
  4              FROM f
  5             START WITH f.id IN ( SELECT idf FROM s )
  6             CONNECT BY PRIOR f.idp = f.id
  7         ) s
  8   WHERE s.id = p.idf
  9       ;
ID
D6
D2
Use this as a subquery in a hierarchial query for the
descendents in D...
SQL> SELECT d.id
  2    FROM d
  3   START WITH d.idd IN ( SELECT p.idd
  4                         FROM p
  5                            , ( SELECT f.id
  6                                  FROM f
  7                                 START WITH f.id IN ( SELECT
idf FROM s )
  8                                 CONNECT BY PRIOR f.idp = f.id
  9                             ) s
10                        WHERE s.id = p.idf
11                      )
12   CONNECT BY PRIOR d.id = d.idp
13       ;
ID
D2
D3
D4
D6
Then use that as a subquery to return the I result set...
SQL> SELECT i.id
  2    FROM i
  3   WHERE i.idd  IN  ( SELECT d.id
  4                        FROM d
  5                       START WITH d.id IN ( SELECT p.idd
  6                                             FROM p
  7                                                , ( SELECT
f.id
  8                                                      FROM f
  9                                                     START
WITH f.id IN ( SELECT idf FROM s )
10                                                     CONNECT
BY PRIOR f.idp = f.id
11                                                 ) s
12                                            WHERE s.id = p.idf
13                                          )
14                       CONNECT BY PRIOR d.id = d.idp
15                    )
16       ;
ID
I2
I3
I4
I6Good Luck...