Can you describe how database migrations are implemented and applied?

Database migrations are a way to manage changes to the database structure (such as adding tables, modifying columns) in a controlled and repeatable manner. In iOS projects, especially when using Core Data, migrations help update the data model without losing user data.

Implementing migrations typically involves:

• Creating a new version of the data model.
• Defining migration rules (automatic or custom).
• Applying the migration at app launch to update the data store.

Example: when adding a new attribute to an entity in Core Data, Xcode can automatically generate a migration that updates the existing database on the next app launch.

This allows for smooth development of the data structure without needing to reset or manually modify the database.