Re: [Modeling-users] Execute arbitrary SQL within an EditingContext

[Sebastien B. <sbi...@us...>]

Matt Goodall <ma...@po...> writes:
> >>    * maintaining a hierarchy of objects stored as a nested set
> >>
> >Could you elaborate on that?
> >
> Nested sets are a reasonably common way of describing a hierarchy of obje=
cts
> using a relational model. Here's a link to one article about it,
> http://www.intelligententerprise.com/001020/celko.shtml, but there are pl=
enty
> of others.
>=20
> The nested set example in the article is somewhat simplified since everyt=
hing
> is in one table. It is quite reasonable to have the left and right node
> information in one table (nested set), the object's "real" data in another
> table (object) and a foreign key to connect them. In this configuration it
> makes more sense to me to maintain the nested set table with direct SQL b=
ut
> let the ORM handle the object.

Wow, I remember having applied this to trees when I was doing some
discrete math., but didn't ever apply it to data structures. Nice,
indeed, thanks for the link, now I have two more things, formerly
separated, connected in my brain ;)

  Roaming around the web to read more about this, I've found this
  article you may find interseting as well:=20
  http://www.dbazine.com/tropashko4.html

        Regards,

-- S=E9bastien.