Django Run Migrations

When to use

Use this skill continuously after modifying any models.py schema logic to apply the changes to the database.

Steps

1. Navigate to the app context: cd app/
2. Generate the required migration definitions by running: python manage.py makemigrations
3. Execute and apply the generated migration file to the DB safely: python manage.py migrate

Validation

1. Verify that the terminal explicitly outputs "Applying..." states and succeeds without tracebacks.
2. Quickly review the auto-generated .py migration output to ensure logical alignment with your model edits.

Gotchas

• Do not manually edit auto-generated migration files unless executing an explicitly necessary, advanced requirement (i.e. complex data backfill operations). Never rewrite migrations that have already been applied to a shared or production database; instead, create a new migration for any additional schema changes.

Tips

If your changes in Django models don't cause a change in the actual database schema, you don't need to create a migration at all.

Typical changes that do not affect the DB schema include:

• choices
• verbose_name
• help_text

In these cases:

• Do not run makemigrations just to capture these metadata-only changes.
• Do not edit existing migration files that may already have been applied. The only safe exception is in a narrowly scoped, pre-merge situation where a migration has never been applied to any shared or production database and you are cleaning up that pending migration before it lands. Otherwise, always create a new migration to capture real schema changes.