[SQLObject] Fwd: [TurboGears] Re: How to create tables with cyclic references?

[Kevin D. <da...@gm...>]

Hi JP,

I'm forwarding your message on to the SQLObject list for further review.

Does your patch include unit tests?

Kevin

---------- Forwarded message ----------
From: Jo=E3o Paulo Fernandes Farias <jpa...@gm...>
Date: Oct 2, 2005 9:09 AM
Subject: [TurboGears] Re: How to create tables with cyclic references?
To: tur...@go...


Hi!

 I've patched SQLObject to do late reference on creation of tables.

 It is no 100%, but it is a starting point.

 I've attached the patch.

 --
 JP


On 10/1/05, Ian Bicking <ia...@co...> wrote:
>
> Jo=E3o Paulo Fernandes Farias wrote:
> > Hi!
> >
> > How do I create tables with cyclic references?
> >
> > As an example, suppose we have two classes:
> >
> > class A(SQLObject):
> >     b =3D ForeignKey('B')
> >
> > class B(SQLObject):
> >     a =3D ForeignKey('A')
> >
> >
> > /me using turbogears...
> >
> > I issue a: turbogears-admin.py sql create
> >
> > It gives me some erros because it tries to create table A but B does no=
t
> > exists, so it cannot be referenced.
> >
> > My suggestion is: Create all tables and then issue all the "alter table
> > add constraint" as necessary.
>
> This is kind of hard.  Technically you can do it like:
>
> class A(SQLObject):
>     b =3D ForeignKey('B')
>
> class B(SQLObject):
>     pass
>
> def create():
>     B.createTable()
>     A.createTable()
>     B.sqlmeta.addColumn(ForeignKey(name=3D'a', foreignKey=3D'A'),
> changeSchema=3DTrue)
>
>
> However, this won't work with sqlobject-admin (and thus
> turbogears-admin.py).
>




--
Kevin Dangoor
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