A third alternative is to use a GenericForeignKey. Although this may
add too much complexity. Put the GenericForeignKey in a model called
PhotoTag and create a M2M relationship between it and Photo and use it
to select either a Place or a UserProfile, i.e.
class PhotoTag(models.Model)
content_type = models.ForeignKey(ContentType)
object_id = models.PositiveIntegerField()
tag_object = generic.GenericForeignKey('content_type', 'object_id')
class Meta:
unique_together = ('content_type', 'object_id')
I use this in a similar, but far more complex situation. I have
overidden the save in my relevant models (in this case UserProfile and
Place) to automatically create the the PhotoTag object when creating
new objects.
-richard
On 5/13/08, Scott Moonen <[EMAIL PROTECTED]> wrote:
> Michael, you have two alternatives:
>
> Create ManyToManyField fields in the UserProfile and Place models, pointing
> to Photo. "ManyToManyField" may seem a bit odd since you really have a
> many-to-one relation, but it will work as you expect, creating a join table
> connecting each pair of models.
> Create two ForeignKey fields in Photo, one to UserProfile and one to Photo,
> with null=True. Yes, this is a bit ugly. :)
> -- Scott
>
> On Tue, May 13, 2008 at 2:24 PM, Michael Burton <[EMAIL PROTECTED]> wrote:
> >
> > I have some Places and I have some Users in my database. I'd like to
> > be able to associate some Photos with each.
> >
> > class Photo(models.Model):
> > # a model that represents a photo
> >
> > class UserProfile(models.Model):
> > # has a list of Photos
> >
> > class Place(models.Model):
> > # has a list of Photos
> >
> >
> > Normally, if i were using another ORM framework, I would make my Place
> > have a list of photos, and I'd make my UserProfile have a list of
> > photos, and I'd leave my Photo model alone. However, the Django way
> > of doing things requires that I put a ForeignKey into my Photo model
> > to establish the one-to-many.
> >
> > The problem is, sometimes Photo's ForeignKey will point to a
> > UserProfile and sometimes to an Place. How can I have both my
> > UserProfile and Place models point to Photos?
> >
> > Thanks in advance,
> > Mike
> >
> >
>
>
>
> --
> http://scott.andstuff.org/ | http://truthadorned.org/
>
> >
>
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