Pre-flight checks

The most common seeding failure in a real project isn't the value generator — it's the database being out of step with the models. django-data-seed checks first and stops with a fixable message, instead of failing halfway through an insert.

Every run starts with a live checklist:

Pre-flight
  ✔ Database: postgresql (JSON ✓, bulk-returns-pk ✓)
  ✔ Migrations: all applied
  ✔ Schema: 14 models in sync
  ✔ Model drift: models match migrations

What it checks

Check	What it catches
Migrations	Unapplied migrations — stops and tells you to run migrate, rather than failing on a missing column mid-run.
Schema	A selected model whose table doesn't exist (e.g. a managed=False surprise).
Model drift	Model changes nobody has made a migration for yet (advisory, unless a model being seeded is affected).
Database probe	The backend's capabilities — native UUID/JSON, whether bulk_create returns primary keys, datetime precision — which the engine then adapts to.

Using it as a health check

Because --dry-run runs the full pre-flight and then stops, it doubles as a fast "is my database in sync with my models?" command — see the Check DB health guide.

python manage.py seeddata --dry-run

Skipping it

If you know your schema is fine and want to save the check, bypass the pre-flight phase:

python manage.py seeddata --no-preflight