Converting a Managed Object Model to Use Versioning

Steps

1. In the project navigator, select the managed object model.

2. Choose Editor > Convert to Versioned Model.

3. In the dialog, choose a name for the model, and if necessary choose the group and target for the model.

4. Click Save.

Convert a managed object model to use versioning when you need to change the schema in an application you have already released. To convert existing persistent stores to the new schema, use Core Data’s migration feature—see the definitive discussion for information on migration.

Xcode automatically creates two versions of the model, both with the same schema as the original. One version is named Filename 2.xcdatamodel and is set as the current version. Core Data ignores the name of the model, so you can use your own naming scheme to keep track of revision numbers.

If you are using a source version control system such as Subversion, ensure that the old model file is removed from your repository, and the new model directory and files are added to your repository.