Hierarchical sys_connect_by_path query needing to process child results

Question

Application Express 4.0.2.00.06 - DB 10.2
Hello all!
I work for an organization having rooms, each with a defined relationship to some or all of the other rooms (some higher, some lower) which must be observed by personnel moving between them.
I've been tasked with writing an page(extending an existing app in which the relationships are managed) in which if a user provide a list of rooms they wish to visit, a list of hierarchy options will be provided based on the relationship rules between rooms.
It is implied that given a sourcename/destname pair, sourcename can go to destname and the inverse is also true (destname can come/receive from sourcename)
This is my sample data set (heavily filtered from actual data);
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME
28          Ax1          76          G3A
28          Ax1          27          FGB44
58          MP23          27          FGB44
58          MP23          104          MP22
58          MP23          76          G3A
76          G3A          27          FGB44
104          MP22          76          G3A
104          MP22          58          MP23Using this query, I'm able to build the beginning of my hierarchy.
SELECT DISTINCT source_roomid,
                sourcename,
                dest_roomid,
                destname,
                sourcename|| ',' ||REVERSE(sys_connect_by_path(REVERSE(destname),',')) path,
                (REVERSE(sys_connect_by_path(REVERSE(sourcename),',')))parents,
                (REVERSE(sys_connect_by_path(REVERSE(destname),',')))children
FROM           (SELECT source_roomid, A.NAME AS sourcename, dest_roomid, b.NAME AS destname
                FROM   rm_approved_room_state, rm_room A, rm_room b
                WHERE  source_roomid IN (27, 28, 58, 76, 104)
                AND    dest_roomid IN (27, 28, 58, 76, 104)
                AND    a.roomid = source_roomid
                AND    b.roomid = dest_roomid)
--START WITH     source_roomid IN (27, 28, 58, 76, 104)
CONNECT BY NOCYCLE PRIOR source_roomid = dest_roomid
order by 1And my initial result set is:
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME     PATH               PARENTS          CHILDREN     
28          Ax1          27          FGB44          Ax1,FGB44,          Ax1,          FGB44,
28          Ax1          76          G3A          Ax1,G3A,          Ax1,          G3A,
28          Ax1          76          G3A          Ax1,G3A,FGB44,          Ax1,G3A,     G3A,FGB44,
58          MP23          27          FGB44          MP23,FGB44,          MP23,          FGB44,
58          MP23          76          G3A          MP23,G3A,          MP23,          G3A,
58          MP23          76          G3A          MP23,G3A,FGB44,          MP23,G3A,     G3A,FGB44,
58          MP23          104          MP22          MP23,MP22,          MP23,          MP22,
58          MP23          104          MP22          MP23,MP22,G3A,          MP23,MP22,     MP22,G3A,
58          MP23          104          MP22          MP23,MP22,G3A,FGB44,     MP23,MP22,G3A,     MP22,G3A,FGB44,
58          MP23          104          MP22          MP23,MP22,MP23,          MP23,MP22,     MP22,MP23,
76          G3A          27          FGB44          G3A,FGB44,          G3A,          FGB44,
104          MP22          58          MP23          MP22,MP23,          MP22,          MP23,
104          MP22          58          MP23          MP22,MP23,FGB44,     MP22,MP23,     MP23,FGB44,
104          MP22          58          MP23          MP22,MP23,G3A,          MP22,MP23,     MP23,G3A,
104          MP22          58          MP23          MP22,MP23,G3A,FGB44,     MP22,MP23,G3A,     MP23,G3A,FGB44,
104          MP22          58          MP23          MP22,MP23,MP22,          MP22,MP23,     MP23,MP22,
104          MP22          76          G3A          MP22,G3A,          MP22,          G3A,
104          MP22          76          G3A          MP22,G3A,FGB44,          MP22,G3A,     G3A,FGB44,The challenge for me is that for the hierarchy to be correct, every hierarchy row where level >= 2 needs a check to determine if the latest child can receive from the previous child otherwise filter those lines out. Also, paths where there is duplicated data needs to be removed leaving the longest heirarchy intact.
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME     PATH               PARENTS          CHILDREN     
28          Ax1          27          FGB44          Ax1,FGB44,          Ax1,          FGB44,
  (****THE NEXT LINE IS NOT NECESSARY BECAUSE THE NEXT LINE ALREADY CONTAINS THIS HIERARCHY DATA****)
28          Ax1          76          G3A          Ax1,G3A,          Ax1,          G3A,
28          Ax1          76          G3A          Ax1,G3A,FGB44,          Ax1,G3A,     G3A,FGB44,I also need to pull out instances of where rooms related to each other as in this case.
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME     PATH               PARENTS          CHILDREN
104          MP22          58          MP23          MP22,MP23,MP22,          MP22,MP23,     MP23,MP22,Leaving this as the anticipated output.
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME     PATH               PARENTS          CHILDREN     
28          Ax1          27          FGB44          Ax1,FGB44,          Ax1,          FGB44,
28          Ax1          76          G3A          Ax1,G3A,FGB44,          Ax1,G3A,     G3A,FGB44,
58          MP23          27          FGB44          MP23,FGB44,          MP23,          FGB44,
58          MP23          76          G3A          MP23,G3A,FGB44,          MP23,G3A,     G3A,FGB44,
58          MP23          104          MP22          MP23,MP22,G3A,          MP23,MP22,     MP22,G3A,
76          G3A          27          FGB44          G3A,FGB44,          G3A,          FGB44,
104          MP22          58          MP23          MP22,MP23,G3A,          MP22,MP23,     MP23,G3A,
104          MP22          76          G3A          MP22,G3A,          MP22,          G3A,Any thoughts on how I might get these last three things done in my hierarchy example?
Many thanks in advance!
Paul
Edited by: pgtaviator on Nov 9, 2011 4:34 PM

Answer 1

Hi, Paul,
Sorry, it's unclear what you want.
pgtaviator wrote:
Application Express 4.0.2.00.06 - DB 10.2
Hello all!
I work for an organization having rooms, each with a defined relationship to some or all of the other rooms (some higher, some lower) which must be observed by personnel moving between them.
I've been tasked with writing an page(extending an existing app in which the relationships are managed) in which if a user provide a list of rooms they wish to visit, a list of hierarchy options will be provided based on the relationship rules between rooms.
It is implied that given a sourcename/destname pair, sourcename can go to destname and the inverse is also true (destname can come/receive from sourcename)If "the inverse is also true", why don't the desired results include any paths such as
G3A,Ax1     or
FGB44,MP23,MP22     ?
This is my sample data set (heavily filtered from actual data);
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME
28          Ax1          76          G3A
28          Ax1          27          FGB44
58          MP23          27          FGB44
58          MP23          104          MP22
58          MP23          76          G3A
76          G3A          27          FGB44
104          MP22          76          G3A
104          MP22          58          MP23
Please post CREATE TABLE and INSERT statements for the sample data.
Is this de-normalized data? That is, does roomid=28 always correspond to name='Ax1', and name='Ax1' always correspond to roomid=28? If not, include examples in your sample data and results, and explain.
Using this query, I'm able to build the beginning of my hierarchy.
SELECT DISTINCT source_roomid,
sourcename,
dest_roomid,
destname,
sourcename|| ',' ||REVERSE(sys_connect_by_path(REVERSE(destname),',')) path,
(REVERSE(sys_connect_by_path(REVERSE(sourcename),',')))parents,
(REVERSE(sys_connect_by_path(REVERSE(destname),',')))children
FROM           (SELECT source_roomid, A.NAME AS sourcename, dest_roomid, b.NAME AS destname
FROM   rm_approved_room_state, rm_room A, rm_room b
WHERE  source_roomid IN (27, 28, 58, 76, 104)
AND    dest_roomid IN (27, 28, 58, 76, 104)
AND    a.roomid = source_roomid
AND    b.roomid = dest_roomid)
--START WITH     source_roomid IN (27, 28, 58, 76, 104)
CONNECT BY NOCYCLE PRIOR source_roomid = dest_roomid
order by 1
Thanks for posting the existing query; that's very helpful.
REVERSE is not a documented Oracle function. Using undocumneted functions isn't a very good idea. In this case, can't you just change the CONNECT BY clause to:
CONNECT BY NOCYCLE       source_roomid = PRIOR dest_roomidto get the results you want?
And my initial result set is:
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME     PATH               PARENTS          CHILDREN     
28          Ax1          27          FGB44          Ax1,FGB44,          Ax1,          FGB44,
28          Ax1          76          G3A          Ax1,G3A,          Ax1,          G3A,
28          Ax1          76          G3A          Ax1,G3A,FGB44,          Ax1,G3A,     G3A,FGB44,
58          MP23          27          FGB44          MP23,FGB44,          MP23,          FGB44,
58          MP23          76          G3A          MP23,G3A,          MP23,          G3A,
58          MP23          76          G3A          MP23,G3A,FGB44,          MP23,G3A,     G3A,FGB44,
58          MP23          104          MP22          MP23,MP22,          MP23,          MP22,
58          MP23          104          MP22          MP23,MP22,G3A,          MP23,MP22,     MP22,G3A,
58          MP23          104          MP22          MP23,MP22,G3A,FGB44,     MP23,MP22,G3A,     MP22,G3A,FGB44,
58          MP23          104          MP22          MP23,MP22,MP23,          MP23,MP22,     MP22,MP23,
76          G3A          27          FGB44          G3A,FGB44,          G3A,          FGB44,
104          MP22          58          MP23          MP22,MP23,          MP22,          MP23,
104          MP22          58          MP23          MP22,MP23,FGB44,     MP22,MP23,     MP23,FGB44,
104          MP22          58          MP23          MP22,MP23,G3A,          MP22,MP23,     MP23,G3A,
104          MP22          58          MP23          MP22,MP23,G3A,FGB44,     MP22,MP23,G3A,     MP23,G3A,FGB44,
104          MP22          58          MP23          MP22,MP23,MP22,          MP22,MP23,     MP23,MP22,
104          MP22          76          G3A          MP22,G3A,          MP22,          G3A,
104          MP22          76          G3A          MP22,G3A,FGB44,          MP22,G3A,     G3A,FGB44,The challenge for me is that for the hierarchy to be correct, every hierarchy row where level >= 2 needs a check to determine if the latest child can receive from the previous child otherwise filter those lines out.I don't understand the requirement above at all.
Also, paths where there is duplicated data needs to be removed leaving the longest heirarchy intact.
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME     PATH               PARENTS          CHILDREN     
28          Ax1          27          FGB44          Ax1,FGB44,          Ax1,          FGB44,
(****THE NEXT LINE IS NOT NECESSARY BECAUSE THE NEXT LINE ALREADY CONTAINS THIS HIERARCHY DATA****)
28          Ax1          76          G3A          Ax1,G3A,          Ax1,          G3A,
28          Ax1          76          G3A          Ax1,G3A,FGB44,          Ax1,G3A,     G3A,FGB44,
Are you using "THE NEXT LINE" to mean 2 different things? Do you mean "The line with Ax1,G3A is not wanted because it is a sub-path of Ax1,G3A,FGB44"?
Why do the desired results include
MP22,G3A     (which is a sub-path of MP23.MP22,G3A) and
G3A,FGB44     (which is a sub-path of both Ax1,G3A,FGB44 and MP23,G3A,FGB44)?
I also need to pull out instances of where rooms related to each other as in this case.
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME     PATH               PARENTS          CHILDREN
104          MP22          58          MP23          MP22,MP23,MP22,          MP22,MP23,     MP23,MP22,
When you way "rooms related to each other", do you mean "rooms related to themselves"? It looks like you're saying that no room can occur 2 (or more) times in any path.
Leaving this as the anticipated output.
SOURCE_ROOMID     SOURCENAME     DEST_ROOMID     DESTNAME     PATH               PARENTS          CHILDREN     
28          Ax1          27          FGB44          Ax1,FGB44,          Ax1,          FGB44,
28          Ax1          76          G3A          Ax1,G3A,FGB44,          Ax1,G3A,     G3A,FGB44,
58          MP23          27          FGB44          MP23,FGB44,          MP23,          FGB44,
58          MP23          76          G3A          MP23,G3A,FGB44,          MP23,G3A,     G3A,FGB44,
58          MP23          104          MP22          MP23,MP22,G3A,          MP23,MP22,     MP22,G3A,
76          G3A          27          FGB44          G3A,FGB44,          G3A,          FGB44,
104          MP22          58          MP23          MP22,MP23,G3A,          MP22,MP23,     MP23,G3A,
104          MP22          76          G3A          MP22,G3A,          MP22,          G3A,
Why do 3 of the paths end at G3A? Why don't they continue to FGB44 as 2 of the paths do?
Why is MP23,G3A,FGB44 in the desired output, and not MP22,MP23,G3A,FGB44 (which is longer)?
Why isn't MP22,MP23,FGB44 in the desired results, but its sub-path MP23,FGB44 is?
Try describing what you're trying to show in this query, and what each row of the desired result set represents. As far as possible, avoid repeating the explanation you're already used. (Not that there's anything wrong with what you've said so far; it's just that I need all the help I can get to understand the probhlem.)
Any thoughts on how I might get these last three things done in my hierarchy example?It looks like CONNECT_BY_ISLEAF, and maybe CONNECT_BY_ISCYCLE could help in this problem.
Regular expressions, or perhaps LIKE, might help in detecting if one path contains another.
Many thanks in advance!
Paul
Edited by: pgtaviator on Nov 9, 2011 4:34 PM