"LookupError: App 'xxxxx' doesn't have a 'xxxxx' model" with custom table name

[John]

Hi,

I recently wrote a migration script in order to migrate some date and one of the model uses a custom table name using db_table (let's call it "myapp_my_custom_table")

When I try to run the migration I got this error:
LookupError: App 'myapp' doesn't have a 'mymodel' model

After investigating, I found out that the model name MyModel (not the real one) is put in lower case then used as key to fetch the actual model class (
django.apps.config.AppConfig#get_model )

One of the item of the self.models is named after the db_table my_custom_table, instead of the model name mymodel

The solution I found is to pass the table name instead of the model name.

Before:

def migrate_data(apps, schema_editor):
    mymodel_model = apps.get_model(
        app_label='myapp',
        model_name='MyModel')

After:

def migrate_data(apps, schema_editor):
    mymodel_model = apps.get_model(
        app_label='myapp',
        model_name='my_custom_table')