[Python] i am facing django.db.migrations.exceptions.InvalidBasesError Cannot resolve bases,...

I have two apps, coreapp and product app. As all models in product app have common fields , i created a BaseModel in coreapp and then inherited the BaseModel in the models in product app. Then i ran python manage.py makemigrations and python manage.py migrate. After that i made some changes in the models, I added abstract = True in BaseModel and renamed some fields in the models in product app. Then i ran python manage.py makemigrations. Now, when i run python manage.py migrate i get the following error

django.db.migrations.exceptions.InvalidBasesError: Cannot resolve bases for [<ModelState: 'product.Attribute'>, <ModelState: 'product.Category'>, <ModelState: 'product.Product'>, <ModelState: 'product.AttributeValue'>]
This can happen if you are inheriting models from an app with migrations (e.g. contrib.auth)
in an app with no migrations; see https://docs.djangoproject.com/en/4.1/topics/migrations/#dependencies for more


Below are the two models

coreapp/models.py

from django.db import models

# Create your models here.

class BaseModel(models.Model):
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)


product/models.py

from django.db import models

from project_root.coreapp.models import BaseModel
# Create your models here.

class Attribute(BaseModel):
title = models.CharField(max_length=100)

def __str__(self):
return self.title

class AttributeValue(BaseModel):
title = models.CharField(max_length=100)
attribute_object = models.ForeignKey(Attribute,on_delete=models.CASCADE, related_name='attribute_values')

def __str__(self):
return self.title

class Category(BaseModel):
title = models.CharField(max_length=200)
parent= models.ForeignKey('self', on_delete=models.CASCADE, null=True, blank=True)
def __str__(self):
return self.title

class Product(BaseModel):
title = models.CharField(max_length=500)
price = models.FloatField()
qty = models.BigIntegerField()
sku = models.CharField(max_length=100)
detail= models.TextField(max_length=5000)
category_object = models.ForeignKey(Category, on_delete=models.CASCADE, related_name='products')

def __str__(self):
return self.title


When I ran python manage.py makemigrations first time i got the following migration files.

coreapp/migrations/0001_initial.py

from django.db import migrations, models


class Migration(migrations.Migration):

initial = True

dependencies = [
]

operations = [
migrations.CreateModel(
name='BaseModel',
fields=[
('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('created_at', models.DateTimeField(auto_now_add=True)),
('updated_at', models.DateTimeField(auto_now=True)),
],
),
]


product/migrations/0001_initial.py

# Generated by Django 4.1 on 2023-10-15 05:59

from django.db import migrations, models
import django.db.models.deletion


class Migration(migrations.Migration):

initial = True

dependencies = [
('coreapp', '0001_initial'),
]

operations = [
migrations.CreateModel(
name='Attribute',
fields=[
('basemodel_ptr', models.OneToOneField(auto_created=True,
on_delete=django.db.models.deletion.CASCADE,
parent_link=True, primary_key=True, serialize=False,
to='coreapp.basemodel')),
('title', models.CharField(max_length=100)),
],
bases=('coreapp.basemodel',),
),
migrations.CreateModel(
name='Category',
fields=[
('basemodel_ptr', models.OneToOneField(auto_created=True,
on_delete=django.db.models.deletion.CASCADE,
parent_link=True, primary_key=True, serialize=False,
to='coreapp.basemodel')),
('title', models.CharField(max_length=200)),
('parent', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE,
to='product.category')),
],
bases=('coreapp.basemodel',),
),
migrations.CreateModel(
name='Product',
fields=[
('basemodel_ptr', models.OneToOneField(auto_created=True,
on_delete=django.db.models.deletion.CASCADE,
parent_link=True, primary_key=True, serialize=False,
to='coreapp.basemodel')),
('title', models.CharField(max_length=500)),
('price', models.FloatField()),
('qty', models.BigIntegerField()),
('sku', models.CharField(max_length=100)),
('detail', models.TextField(max_length=5000)),
('category_object', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE,
related_name='products', to='product.category')),
],
bases=('coreapp.basemodel',),
),
migrations.CreateModel(
name='AttributeValue',
fields=[
('basemodel_ptr', models.OneToOneField(auto_created=True,
on_delete=django.db.models.deletion.CASCADE,
parent_link=True, primary_key=True, serialize=False,
to='coreapp.basemodel')),
('title', models.CharField(max_length=100)),
('attribute_object', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE,
related_name='attribute_values', to='product.attribute')),
],
bases=('coreapp.basemodel',),
),
]
print('product migration 1')


then I added abstract=True in BaseModel and renamed fieild attribute_object to attribute in AttributeValue model and category_object to category in Product model. After that i ran python manage.py makemigrations and got the following migrations files

coreapp/migrations/0002_delete_basemodel.py

# Generated by Django 4.1 on 2023-10-15 06:03

from django.db import migrations


class Migration(migrations.Migration):

dependencies = [
('product', '0002_rename_attribute_object_attributevalue_attribute_and_more'),
('coreapp', '0001_initial'),
]

operations = [
migrations.DeleteModel(
name='BaseModel',
),
]


product/migrations/0002_rename_attribute_object_attributevalue_attribute_and_more.py

# Generated by Django 4.1 on 2023-10-15 06:03

from django.db import migrations, models
import django.utils.timezone


class Migration(migrations.Migration):

dependencies = [
('product', '0001_initial'),
]

operations = [
migrations.RenameField(
model_name='attributevalue',
old_name='attribute_object',
new_name='attribute',
),
migrations.RenameField(
model_name='product',
old_name='category_object',
new_name='category',
),
migrations.RemoveField(
model_name='attribute',
name='basemodel_ptr',
),
migrations.RemoveField(
model_name='attributevalue',
name='basemodel_ptr',
),
migrations.RemoveField(
model_name='category',
name='basemodel_ptr',
),
migrations.RemoveField(
model_name='product',
name='basemodel_ptr',
),
migrations.AddField(
model_name='attribute',
name='created_at',
field=models.DateTimeField(auto_now_add=True, default=django.utils.timezone.now),
preserve_default=False,
),
migrations.AddField(
model_name='attribute',
name='id',
field=models.BigAutoField(auto_created=True, default=1, primary_key=True, serialize=False,
verbose_name='ID'),
preserve_default=False,
),
migrations.AddField(
model_name='attribute',
name='updated_at',
field=models.DateTimeField(auto_now=True),
),
migrations.AddField(
model_name='attributevalue',
name='created_at',
field=models.DateTimeField(auto_now_add=True, default=django.utils.timezone.now),
preserve_default=False,
),
migrations.AddField(
model_name='attributevalue',
name='id',
field=models.BigAutoField(auto_created=True, default=1, primary_key=True, serialize=False,
verbose_name='ID'),
preserve_default=False,
),
migrations.AddField(
model_name='attributevalue',
name='updated_at',
field=models.DateTimeField(auto_now=True),
),
migrations.AddField(
model_name='category',
name='created_at',
field=models.DateTimeField(auto_now_add=True, default=django.utils.timezone.now),
preserve_default=False,
),
migrations.AddField(
model_name='category',
name='id',
field=models.BigAutoField(auto_created=True, default=1, primary_key=True, serialize=False,
verbose_name='ID'),
preserve_default=False,
),
migrations.AddField(
model_name='category',
name='updated_at',
field=models.DateTimeField(auto_now=True),
),
migrations.AddField(
model_name='product',
name='created_at',
field=models.DateTimeField(auto_now_add=True, default=django.utils.timezone.now),
preserve_default=False,
),
migrations.AddField(
model_name='product',
name='id',
field=models.BigAutoField(auto_created=True, default=1, primary_key=True, serialize=False,
verbose_name='ID'),
preserve_default=False,
),
migrations.AddField(
model_name='product',
name='updated_at',
field=models.DateTimeField(auto_now=True),
),
]

print('product migration 2')


Now when I run python manage.py migrate i get the error

django.db.migrations.exceptions.InvalidBasesError: Cannot resolve bases for [<ModelState: 'product.Attribute'>, <ModelState: 'product.Category'>, <ModelState: 'product.Product'>, <ModelState: 'product.AttributeValue'>]
This can happen if you are inheriting models from an app with migrations (e.g. contrib.auth)
in an app with no migrations; see https://docs.djangoproject.com/en/4.1/topics/migrations/#dependencies for more


I tried migrating the app separately in different order like

python manage.py migrate product
python manage.py migrate coreapp


i also tried changing the order of dependencies in migration files

but none worked.

How do I resolve this issue?

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