Django admin外键相关

Question

I have such models.

class Country(models.Model)
    name = models.CharField(200)

class Zone(models.Model)
    country = models.ForeignKey(Country)
    name = models.CharField(200)

class Town(models.Model)
    zone = models.ForeignKey(Zone)
    name = models.CharField(200)

class Resource(models.Model)
    country = models.ForeignKey(Country)
    zone = models.ForeignKey(Zone)
    town = models.ForeignKey(Town)
    name = models.CharField(max_length=200)
    ...

I want to edit Resource model in django admin. As I have 3 million town records, when I try to edit Resource, site halts because of town. I just want to select towns related to zones only. If Zone is changed in Resource admin page, then related towns are displayed also.

Is there any idea to implement this?

I could do it when I display admin form using this function https://docs.djangoproject.com/en/1.4/ref/contrib/admin/#django.contrib.admin.ModelAdmin.formfield_for_foreignkey

but I just want to load towns dynamically according to zone.

Answer 1

What you're looking for is the chained select feature of django-smart-selects .

It will populate select box B when a value changes in select box A.

Answer 2

An alternative option to solution You want, would be to use the built-in raw_id_fields attribute in your ModelAdmin class.

Foreign keys specified in the raw_id_fields option will display currently selected value (town in your case) and a link that opens a full-featured list of towns with sorting, filtering and search form. Example screenshot from Django docs:

See docs for more: https://docs.djangoproject.com/en/1.4/ref/contrib/admin/#django.contrib.admin.ModelAdmin.raw_id_fields