Re: Heirarchical Data Structures. MS Access. Together?
Date: 24 Jul 2003 14:14:03 -0700
Message-ID: <6dae7e65.0307240543.52963da6_at_posting.google.com>
"Jace Harker" <jharker_at_marlboro.edu> wrote in message news:<vhuhvgjqr27d83_at_corp.supernews.com>...
> "--CELKO--" <71062.1056_at_compuserve.com> wrote in message
> news:c0d87ec0.0307220645.2ccab82f_at_posting.google.com...
[...]
> Very nice! Once I saw what you were getting at, the strategy made perfect
> sense to me. It certainly adds efficiency in several nifty ways, especially
> in finding removed parents of children.
>
In most cases - IMHO - one should not allow removal of a parent (i.e. someone that has children). Instead add functionlity that prevents removal of such nodes. Dont know how that is done in the "pure" nested set approach, but it is quite easy if you add parentid to the relation. Also, if you are interested in another aproach dealing with hierarchies, drop me a note and I can send you some links.
/Lennart
-- the above email no longer works due to spam. values'lennart'||CHR(46)||'jonsson'||CHR(64)||'enlight'||CHR(46)||'net' [...]Received on Thu Jul 24 2003 - 23:14:03 CEST