Join inheritance is a bit of a new one to me, so there may be more possible
than I thought. But in that scheme, it looks to me as if the resultant
object is a composite of fetches from a number of tables. The core of that
object, though, seems to be a single table, a "root" table. It is that table
that holds the discriminator.

In the scheme you posted, you're trying to use *two* roots, each with its
own discriminator column. I think that is the,  um,   "root" of your
problem.



On Jan 10, 2008 10:08 PM, Alexandre da Silva <[EMAIL PROTECTED]> wrote:

>
>
> Em Qui, 2008-01-10 às 21:20 -0500, Rick Morrison escreveu:
> > You're mixing single-table inheritance (using the discriminator
> > column), with concrete inheritance (using multiple tables).
> >
> > You have to pick one scheme or the other. Either use a single
> > inheritance chain, or separate the two class hierarchies into two
> > separate chains that don't inherit from each other. In the separate
> > scheme, each chain can use it's own discriminator column, but you
> > cannot combine two class hierarchies that each use a different
> > discriminator column.
> >
>
> In fact I am doing what is sugested here:
>
> http://www.sqlalchemy.org/docs/04/mappers.html#advdatamapping_mapper_inheritance_joined
> It works fine with one level inheritance  class->subclass
> but the third subclassing don't working, it was because objects was in
> cache... savint to db and tryin to load again the identity is lost.
>
> how do you suggest to I do this? or I cannot?
>
> --
> Alexandre da Silva
> Analista de Sistemas - Bacharel em Sistemas de Informação (2003-2007)
>
>
> >
>

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