Django: Migration to NullBooleanField is not performed using IntegrityError "contains null values"

Question

I am working in Django 1.7 and trying to migrate a database field with a name is_dispensingfrom an existing one BooleanFieldin NullBooleanField.

My migration file:

# -*- coding: utf-8 -*-
from __future__ import unicode_literals

from django.db import models, migrations

class Migration(migrations.Migration):

    dependencies = [
        ('frontend', '0007_practice_is_dispensing'),
    ]

    operations = [
        migrations.AlterField(
            model_name='practice',
            name='is_dispensing',
            field=models.NullBooleanField(),
            preserve_default=True,
        ),
    ]

The launch manage.py migratefails with the error:

django.db.utils.IntegrityError: column "is_dispensing" contains null values

Field in my models file:

is_dispensing = models.NullBooleanField(blank=True)

It used to be:

is_dispensing = models.BooleanField(null=True, blank=True) 

and when I added it, I was asked to provide the default value that I set to None.

I find this message confusing - I'm trying to transfer the column type to NullBooleanField, so why can't it contain null values? That the whole point of this type of column is, isn't it? :)

UPDATE: , : Postgres , , is_dispensing.

Answer 1

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