Re: Hierarchical Subquery must omit nodes

From: Chris L. <diversos_at_uol.com.ar>
Date: Thu, 17 Apr 2008 08:09:48 -0700 (PDT)
Message-ID: <ad68ae98-35f2-41d9-803d-e5e9fcccf524@26g2000hsk.googlegroups.com>


On Apr 16, 6:43 pm, Urs Metzger <u..._at_ursmetzger.de> wrote:
> fitzjarr..._at_cox.net schrieb:
>
> > On Apr 16, 2:21 pm, "Shakespeare" <what..._at_xs4all.nl> wrote:
> >> "fitzjarr..._at_cox.net" <orat..._at_msn.com> schreef in berichtnews:57056886-02e4-4188-9b29-b7ddf517bbb7_at_a70g2000hsh.googlegroups.com...
> >> On Apr 16, 12:16 pm, "Chris L." <diver..._at_uol.com.ar> wrote:
>
> >>> Hi all,
> >>> I thought this would be easy but it's turning out to be pretty
> >>> difficult.
> >>> I need a hierarchical query to omit nodes present in a EXCLUDED_NODES
> >>> table.
> >>> Omitted nodes' children should be omitted too.
> >>> See this example taken
> >>> fromhttp://download.oracle.com/docs/cd/B10501_01/server.920/a96540/functi...
> >>> SELECT LPAD(' ', 2*level-1)||SYS_CONNECT_BY_PATH(last_name, '/')
> >>> "Path"
> >>> FROM employees
> >>> START WITH last_name = 'Kochhar'
> >>> CONNECT BY PRIOR employee_id = manager_id;
> >>> Path
> >>> ---------------------------------------------------------------
> >>> /Kochhar
> >>> /Kochhar/Greenberg
> >>> /Kochhar/Greenberg/Faviet
> >>> /Kochhar/Greenberg/Chen
> >>> /Kochhar/Greenberg/Sciarra
> >>> /Kochhar/Greenberg/Urman
> >>> /Kochhar/Greenberg/Popp
> >>> /Kochhar/Whalen
> >>> /Kochhar/Mavris
> >>> /Kochhar/Baer
> >>> /Kochhar/Higgins
> >>> /Kochhar/Higgins/Gietz
> >>> If I have Greenberg in EXCLUDED_NODES then output should be
> >>> Path
> >>> ---------------------------------------------------------------
> >>> /Kochhar
> >>> /Kochhar/Whalen
> >>> /Kochhar/Mavris
> >>> /Kochhar/Baer
> >>> /Kochhar/Higgins
> >>> /Kochhar/Higgins/Gietz
> >>> Excluded node can be in any depth of the hierarchy (i.e. it could be
> >>> Gietz and then Gietz and all of its dependent sub-tree should be
> >>> pruned)
> >>> I've tried filtering the START WITH and works great but doesn't help
> >>> when the excluded node is somewhere deep in the hierarchy.
> >>> I've tried filtering the CONNECT BY but it cannot contain subqueries
> >>> (manual states this).
> >>> I've tried using the SYS_CONNECT_BY_PATH to parse it and see if it
> >>> contains an excluded node but I got an Ora-00600 error.
> >>> ORA-00600: internal error code, arguments: [rworupo.2], [26670], [1],
> >>> [], [], [], [], []
> >>> Oracle version is 9i
> >>> Thanks in advance!
> >>> Chris
> >> Why wouldn't this work:
>
> >> -- Your original example
> >> SQL> SELECT LPAD(' ', 2*level-1)||SYS_CONNECT_BY_PATH(last_name, '/')
> >> "Path"
> >> 2 FROM employees
> >> 3 START WITH last_name = 'Kochhar'
> >> 4 CONNECT BY PRIOR employee_id = manager_id;
>
> >> Path
> >> ---------------------------------------------------------------------------ญ-----
> >> /Kochhar
> >> /Kochhar/Greenberg
> >> /Kochhar/Greenberg/Faviet
> >> /Kochhar/Greenberg/Chen
> >> /Kochhar/Greenberg/Sciarra
> >> /Kochhar/Greenberg/Urman
> >> /Kochhar/Greenberg/Popp
> >> /Kochhar/Whalen
> >> /Kochhar/Mavris
> >> /Kochhar/Baer
> >> /Kochhar/Higgins
> >> /Kochhar/Higgins/Gietz
>
> >> 12 rows selected.
>
> >> -- 'Filtered' example
> >> SQL> select "Path"
> >> 2 from
> >> 3 (SELECT LPAD(' ', 2*level-1)||SYS_CONNECT_BY_PATH(last_name,
> >> '/') "Path"
> >> 4 FROM employees
> >> 5 START WITH last_name = 'Kochhar'
> >> 6 CONNECT BY PRIOR employee_id = manager_id)
> >> 7 where instr("Path", 'Greenberg') = 0;
>
> >> Path
> >> ---------------------------------------------------------------------------ญ-----
> >> /Kochhar
> >> /Kochhar/Whalen
> >> /Kochhar/Mavris
> >> /Kochhar/Baer
> >> /Kochhar/Higgins
> >> /Kochhar/Higgins/Gietz
>
> >> 6 rows selected.
>
> >> SQL>
>
> >> David Fitzjarrell
>
> >> --------------------------------
> >> This will go wrong if you want to exclude 'Green' but include 'Greenberg'
>
> >> Shakespeare- Hide quoted text -
>
> >> - Show quoted text -
>
> > A valid concern. I must admit this was a quick and dirty attempt.
>
> > And this is with 10.2.0.3.
>
> > David Fitzjarrell
>
> SQL> create table excluded_nodes(last_name varchar2(25));
>
> Tabelle wurde erstellt.
>
> SQL> insert into excluded_nodes values('Greenberg');
>
> 1 Zeile wurde erstellt.
>
> SQL> commit;
>
> SQL> SELECT LPAD(' ', 2*level-1)||SYS_CONNECT_BY_PATH(last_name, '/') "Path"
> 2 FROM (select *
> 3 from employees
> 4 where last_name not in (select last_name
> 5 from excluded_nodes))
> 6 START WITH last_name = 'Kochhar'
> 7 CONNECT BY PRIOR employee_id = manager_id;
>
> Path
> --------------------------------------------------------------------------------
> /Kochhar
> /Kochhar/Whalen
> /Kochhar/Mavris
> /Kochhar/Baer
> /Kochhar/Higgins
> /Kochhar/Higgins/Gietz
>
> hth,
> Urs Metzger

Thanks Urs, working with a filtered subset and then applying the "connect by" to it is a good idea.
Since I would work with employee_id to exclude, do you think it would be best to filter out both employee_id and manager_id? Or is this a non-issue?

What do you think of this...? sorry about the column name "last_name", it would really contain ids.

> SQL> SELECT LPAD(' ', 2*level-1)||SYS_CONNECT_BY_PATH(last_name, '/') "Path"
> 2 FROM (select *
> 3 from employees
> 4 where not exists (select *
> 5 from excluded_nodes where last_name in (employee_id, manager_id) ))
> 6 START WITH last_name = 'Kochhar'
> 7 CONNECT BY PRIOR employee_id = manager_id;

Appreciate it!
Chris Received on Thu Apr 17 2008 - 10:09:48 CDT

Original text of this message