Re: [SQLObject] proxy attributes

[alexander s. <al...@an...>]

jws...@ra... wrote, at 17.02.2004 21:26:

>>(i do not think that you mean "account is a man" inheritance, do you?)
> 
> Actually, I do.

oh, please don't!  using inheritance ("is-a" relationship) instead of
client ("has-a") relationship between classes is highly error-prone and
often difficult to refactor later.

probably the best paper i've seen on the matter is chapter "Using
inheritance well" of the "Object-Oriented Software Construction" book by
Bertrand Meyer.  this chapter may be downloaded from
http://archive.eiffel.com/doc/manuals/technology/oosc/acrobat.html

however, SQLObject inheritance won't work in your case anyway: neither
is it designed for legacy databases nor can it handle many-to-one
relationships.

> Since python has multiple inheritance, you can see a parallel between joins
> and inheritance. Think of it like a mixin class. Not "account IS a man", 
> account has the properties of a man.

this may mean that both account and man *have* same contact info, or
that account *has* a contact person...  but as far as i understand, you
cannot amend the database structure, so these considerations do not
apply.  in your case, account has a buyer, and you cannot change that.

best wishes,
alex.