django-migration-linter/docs/incompatibilities.md

Backward incompatible migrations

The linter analyses your migrations and checks the SQL for:

• Added NOT NULL columns, which don't have a DEFAULT value
• Dropping columns
• Dropping tables
• Renaming columns
• Renaming tables
• Altering columns (which can be backward compatible and potentially ignored)
• Adding a unique constraint

Those are the most important and frequent backward incompatible migrations. We are happy to add more if you can specify them to us.