How do you reference related models' fields in

问题:

My Models:

OrderInfo is one-to-one with Print, which is a Many-to-One with Painting, which itself is a Many-to-One with Club.

class OrderInfo(models.Model):
    print_ordered = models.OneToOneField(Print, blank=True)

class Print(models.Model):
    painting = models.ForeignKey(Painting)

class Painting(models.Model):
    club = models.ForeignKey(Club)

In my OrderInfoAdmin, I'd like to be able to sort by the related Club, but I can't figure out the syntax to do this.

I tried this, but it does not work:

class OrderInfoAdmin(admin.ModelAdmin):
    list_filter = ['print_ordered__painting__club']

Any help appreciated, thanks in advance!

回答1:

The list_filter command is for filtering not ordering. You want the ordering command which is documented here: http://docs.djangoproject.com/en/dev/ref/models/options/#ordering. It's not clear to me though from the documentation if the modeling Meta command allows ordering through foreign keys. (The filter() queryset function definitely does: http://docs.djangoproject.com/en/dev/ref/models/querysets/#order-by-fields)

I've found the admin has some limitations working with deeply hierarchical models. For example, you can inline a child model on its parent's page, but you can't inline an grandchild. Also, by default the list_filter command only works on fields in the modeled table. In your example, you couldn't filter on the fields of Print in the OrderInfo admin for example.

回答2:

Just today, Josh VanderLinden posted a solution for this on his blog:

Model Relationships and "list_display"

(Found via Django Community)