Core Data Lab

Frequently asked questions

Multi-delete can be used in Core Data Lab after enabling setting Allow multiple selection in the Tables section of the Core Data Lab Preferences..

Database extensions can be added and removed in the Supported database file extensions edit box, located in the Files section of the Core Data Lab Preferences.

Missing or incompatible Core Data object model

In order to open a Core Data database in editable modus, you need to add a compatible Core Data object model to the Core Data Lab project. This may be a cached object model, an object model embedded in an app or an object model file. More info about how to setup a project can be found in the Core Data Model Help.

Database is readonly with a matching Core Data model

Follow these steps to remove the readonly status of a project that has a compatible Core Data object model:

  • In Core Data Lab, choose File > Project Settings in the menu.
  • If checkbox Open as read-only is checked, uncheck it. If this removes the readonly status, then you can close the dialog.
  • Check if setting History tracking is editable. If this is the case, then check checkbox Enable NSPersistentHistoryTracking to make the data in the project editable.

Check the following conditions to make your iOS or iPadOS app visible in the Simulator browser:

  • Your app binary must contain a compiled Core Data object model, or generate a Core Data model during runtime, or it must be a SwiftData app. Classic Core Data apps based on an object model designed in Xcode will normally have an embedded compiled Core Data object model file.
  • If your app contains both a Core Data object model and SwiftData object classes, then these two must be in sync.
  • You must have run the app at least once in a simulator, started from Xcode.
  • The file extension of the database must be present in the Database Extension list in the Files section of the Core Data Lab Preferences. If this is not the case, then you can simply add the extension to the list. When your database doesn’t use a file extension at all, then just add a dot character to the list.

Restart the Simulator browser after correcting one or more of the conditions.