Basic Core Data model versioning

When you add new properties, entities, relationships to an existing data model which is already deployed in production, this will fail with this error:

migration_error

Therewith this does not happen, some steps are necessary. At first, you need to configure Core Data, that data is migrated automatically:

The second step is, to create a new version of the data model for a change. To do this, select the .xcdatamodeld file in your project navigator. Then in the menu, select Add model Version….

create_new_model_versionIn the next dialogue, type in an appropriate version name and click Finish.

 

switch_model_version

 

Before you start to modify the model, select the xcdatamodeld file again
and in the file inspector,
select the current model version.