Alex Letoosh Alex Letoosh - 4 months ago 88
Python Question

Django BigInteger auto-increment field as primary key?

I'm currently building a project which involves a lot of collective intelligence. Every user visiting the web site gets created a unique profile and their data is later used to calculate best matches for themselves and other users.

By default, Django creates an INT(11)

field to handle models primary keys. I'm concerned with this being overflown very quickly (i.e. ~2.4b devices visiting the page without prior cookie set up). How can I change it to be represented as BIGINT in MySQL and long() inside Django itself?

I've found I could do the following (

class MyProfile(models.Model):
id = BigIntegerField(primary_key=True)

But is there a way to make it autoincrement, like usual
fields? Additionally, can I make it unsigned so that I get more space to fill in?



NOTE: This answer as modified, according to Larry's code. Previous solution extended fields.BigIntegerField, but better to extend fields.AutoField

I had the same problem and solved with following code:

from django.db.models import fields
from south.modelsinspector import add_introspection_rules

class BigAutoField(fields.AutoField):
    def db_type(self, connection):
        if 'mysql' in connection.__class__.__module__:
            return 'bigint AUTO_INCREMENT'
        return super(BigAutoField, self).db_type(connection)

add_introspection_rules([], ["^MYAPP\.fields\.BigAutoField"])

Apparently this is working fine with south migrations.