Michael,
I believe the case of query.select_related(person__place) will "only"
follow the place foreign key. This means that if you had 5 FK's in
your person models, that only a single FK would be followed instead of
all 5 for optimization. Upon further looking there is also a "depth"
argument you can pass to select related to specify how far you want it
to go. For example:
query.select_related(depth=5) # This will follow all FK's 5 levels
deep
query.select_ralted('person__place', depth=5) # This will follow only
the place FK 5 levels deep
That is how I read the docs, it may not be correct :)
Cheers,
Dan Harris
dih0...@gmail.com
On Jun 10, 4:54 pm, Michael Hrivnak <mhriv...@americanri.com> wrote:
> I read that myself. I asked the question because it goes on to state that you
> can specify down-stream models like this:
>
> query.select_related(person__place)
>
> If it follows all relationships as far as possible, even when specific
> relationships are requested, why would that syntax ever be necessary? We
> could just specify "people", and it would follow the "place" relationship
> automatically. Is it only to specifically prevent it from following other
> relationships on the "person" model?
>
> The docs seem to be ambiguous on this point.
>
> Thanks,
> Michael
>
> On Thursday 10 June 2010 03:37:59 pm Dan Harris wrote:
>
>
>
> > According to the select_related() documentation at:
> >http://docs.djangoproject.com/en/dev/ref/models/querysets/#django.db....
> > .QuerySet.select_related
>
> > it looks like select related "follows foreign keys as far as
> > possible". In the documentation example it shows select_related
> > following a foreign keys with a depth of two.
>
> > Hope this helps,
>
> > Dan Harris
> > dih0...@gmail.com
>
> > On Jun 10, 3:19 pm, Michael Hrivnak <mhriv...@americanri.com> wrote:
> > > If I use select_related() on a queryset and specify some attribute names,
> > > will it follow those relationships as far as possible, or does that imply
> > > "depth=1"?
>
> > > Thanks,
> > > Michael
>
> > > signature.asc
> > > < 1KViewDownload
>
>
>
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