ProgrammingError: relation does not exist after migration

ProgrammingError: relation does not exist

$ python manage.py shell -c "from app.models import Item; print(Item.objects.count())"
# Traceback with ProgrammingError: relation "app_item" does not exist

Why this happens

Migrations not applied to the current database or you’re pointing to a different DB.

Fix

Run migrations for the active settings and ensure DATABASES points to the correct instance.

Wrong code

# Using test DB settings by accident
DATABASES = test_databases

Fixed code

# Ensure production/dev settings match your environment
# python manage.py migrate