Get a dropdown of states in Django Admin - django

Question

I made some basic models for a listing of a business, like so:
class Business(models.Models):
id = models.IntegerField(primary_key=True)
name = models.CharField(max_length=225, blank=True)
address = models.CharField(max_length=150, blank=True)
city = models.CharField(max_length=150, blank=True)
state_id = models.IntegerField(null=True, blank=True)
zip = models.CharField(max_length=33, blank=True)
country = models.CharField(max_length=150, blank=True)
url = models.CharField(max_length=765, blank=True)
class States(models.Model):
id = models.IntegerField(primary_key=True)
name = models.CharField(max_length=96)
state_abbr = models.CharField(max_length=24, blank=True)
In the admin when I edit each business it shows the state_id field. But how do I connect it with the state model to show a select dropdown listing of the states?
Also, how do I show the state abbreviation in the view of a business?

Answer 1

An alternative that doesn't require a separate state table:
from django.contrib.localflavor.us.us_states import STATE_CHOICES
class Business(models.Models):
...
state = models.CharField(max_length=2, choices=STATE_CHOICES, null=True, blank=True)
...

Answer 2

Edit in 2015 (django 1.8)
you should check the django official localflavor repo: https://github.com/django/django-localflavor.
from localflavor.us.models import USStateField
class Business(models.Models):
…
state = USStateField(null=True, blank=True)
…
Some tests are available on the repo for this specific usage.
Docs available here.

Answer 3

You need to use a ForeignKey field.
Make the following changes.
class Business(models.Models):
id = models.IntegerField(primary_key=True)
name = models.CharField(max_length=225, blank=True)
address = models.CharField(max_length=150, blank=True)
city = models.CharField(max_length=150, blank=True)
#state_id = models.IntegerField(null=True, blank=True)
# Define a new state field that creates a ForeignKey relationship with States
state = models.ForeignKey('States', null=True, blank=True)
zip = models.CharField(max_length=33, blank=True)
country = models.CharField(max_length=150, blank=True)
url = models.CharField(max_length=765, blank=True)
class States(models.Model):
id = models.IntegerField(primary_key=True)
name = models.CharField(max_length=96)
state_abbr = models.CharField(max_length=24, blank=True)
#Define the __unicode__ method, which is used by related models by default.
def __unicode__(self):
return self.state_abbr
By default ForeignKey fields append '_id' to the field name when creating the column name in the database. So, the new "state" field in the Business class will automatically use the column "state_id" that you've previously defined, unless you've changed some of the default behavior of Django.
For more on this:
Check out Django's documentation of
the ForeignKey field
Search "ForeignKey" on stackoverflow.com