> Recently I found an Oracle extension, START WITH .. CONNECT BY, which
> greatly eases parsing of n-way tree structures stored in table format.
>
> I'd prefer implementing this myself, but alas, I feel I need something
> which is a bit easier, to get accustomed to the code base.
>
Hi,
I am currently porting business application from Oracle to PG, for one of our
customers.
I work hardly on migrating CONNECT BY queries, using the really good libraries
from OpenACS project (version 4).
It a kind of 1 day/man to enable tree structure in PG for one table accessed
with a CONNECT BY query.
So I'll be really glad to you if you enable CONNECT BY statments in PG!!
So, what you want to know about connect by statment?
read:
http://www.arsdigita.com/books/sql/trees.html
and:
http://openacs.org/bboard/q-and-a-fetch-msg.tcl?msg_id=0000j6&topic_id=12&topic=OpenACS%204%2e0%20Design
download OpenACS source code for version 4.x and :
We're using this extensively in openacs4. If you download the latest code, you
can find the tree encoding table and some tree-utility routines in
openacs-4/packages/acs-kernel/sql/postgresql/postgresql.sql.For
corresponding trigger routines look at openacs-4/packages/acs-kernel/sql/postgresql/acs-objects-create.sql -
specifically look at the acs_objects table definition and its associated triggers.
With regards to inheritance, we looked seriously at prior to starting the
opeancs4 porting activities and we opted not to use it because it was deficient in serveral areas.
-- Dan Wickstrom, September 7, 2001
Hope this helps
--
Jean-Paul ARGUDO IDEALX S.A.S
Consultant bases de données 15-17, av. de Ségur
http://IDEALX.com/ F-75007 PARIS
