How do I change the choices in a Django model?

Question

I have a Django model that uses the choices attribute.

COLOR_CHOICES = (
    ('R', 'Red'),
    ('B', 'Blue'),
)
class Toy(models.Model):
    color = models.CharField(max_length=1, choices=COLOR_CHOICES)

My code is in production and now I'd like to add additional choices.

COLOR_CHOICES = (
        ('R', 'Red'),
        ('B', 'Blue'),
        ('G', 'Green'),
 )

How do I go about doing this? Does Django use Database constraints to enforce choices? Do I need to do a Database migration (I'm using South)? Or does Django just enforce the choices restriction in Python code and all I have to do is change the code and restart?

Thanks!

score 14 · Accepted Answer · answered Dec 23 '10 at 19:45

14

Django doesn't enforce choices on a database level, it only uses them for the presentation of the widgets and in validation. If you want them a bit more 'dynamic', for example to have different ones on different servers you could define them via settings.py:

from django.conf import settings

COLOR_CHOICES = getattr(settings, 'COLOR_CHOICES',(
        ('R', 'Red'),
        ('B', 'Blue'),
        ('G', 'Green'),
 ))

Then you could define different choices in your settings.py (no need for any database migration!).

answered Dec 23 '10 at 19:45

Bernhard Vallant

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That's a cool idea. But you're saying that as it is there's no need for DB migration. I just need to change the code and restart? – Adam Dec 23 '10 at 19:47
yes... and besides that shouldnt be the big deal to try it, right? – Bernhard Vallant Dec 23 '10 at 20:12
Bit late to the party here... What if I want to change all the 'Reds' to 'Greens'? – Ferguzz May 28 '14 at 11:26
3

@Ferguzz `MyModel.objects.filter(color="R").update(color="G")` – Bernhard Vallant May 28 '14 at 13:02

score 2 · Answer 2 · answered Dec 23 '10 at 20:07

2

The field is models.CharField so the database will treat it like any other models.CharField set up in django :)

No, it doesn't enforce choices / you don't need to touch your DB.

answered Dec 23 '10 at 20:07

Yuji 'Tomita' Tomita

115,817
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How do I change the choices in a Django model?

2 Answers2