Can you achieve a case insensitive 'unique' constraint in Sqlite3 (with Django)?

Question

So let's say I'm using Python 2.5's built-in default sqlite3 and I have a Django model class with the following code:

class SomeEntity(models.Model):
    some_field = models.CharField(max_length=50, db_index=True, unique=True)

I've got the admin interface setup and everything appears to be working fine except that I can create two SomeEntity records, one with some_field='some value' and one with some_field='Some Value' because the unique constraint on some_field appears to be case sensitive.

Is there some way to force sqlite to perform a case insensitive comparison when checking for uniqueness?

I can't seem to find an option for this in Django's docs and I'm wondering if there's something that I can do directly to sqlite to get it to behave the way I want. :-)

Answer 1

For anyone in 2021, with the help of Django 4.0 UniqueConstraint expressions you could add a Meta class to your model like this:

class Meta:
    constraints = [
        models.UniqueConstraint(
            Lower('<field name>'),
            name='<constraint name>'
        ),
    ]