Django multiple primary keys for table error

Question

My Django application is working just fine on localhost, but when I try to push it to Heroku I get the following error:

remote: django.db.utils.ProgrammingError: multiple primary keys for table "Clientes_productlist" are not allowed

My models.py file is:

class ProductList(models.Model):
    id_new = models.IntegerField(primary_key=True)
    sku = models.CharField(max_length=200)
    client = models.ForeignKey(get_user_model(), on_delete=models.CASCADE)
    name = models.CharField(max_length=256)
    description = models.CharField(max_length=1000)
    storage = models.CharField(max_length=256)
    cost_price = models.CharField(max_length=256)
    sell_price = models.CharField(max_length=256)
    ncm = models.CharField(max_length=256)
    inventory = models.IntegerField(null=True)

    class Meta:
        unique_together = (('sku', 'client'),)

I am using django-import-export package as well. Therefore, my resources.py is:

class ProductListResource(resources.ModelResource):

    class Meta:
        model = ProductList
        skip_unchanged = True
        report_skipped = True
        exclude = ('id',)
        import_id_fields = ('sku', 'client',)
        fields = ('sku', 'client', 'name', 'description', 'storage', 'cost_price', 'sell_price', 'ncm', 'inventory',)

What is causing that error and how can I solve it?

Answer 1

To fix that, you need to delete all the migration files in migrations folder of the app in which ProductList model exists, except for __init__.py file and run ./manage.py makemigrations to generate new migrations. Then commit those migrations and push them to Heroku.