如何从核心数据数据库中删除iCloud同步

Question

I have an app, which is using the old iCloud sync and I want to remove this feature. So when I try to remove the 'NSPersistentStoreUbiquitousContentNameKey' from options in persistentStoreCoordinator, I will lose my whole database items. Do anybody know what I have to do? Migration of database?

    let containerPath = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.de.companyName.appname")?.path
    let sqlitePath = NSString(format: "%@/%@", containerPath!, "AppName")
    let url = URL(fileURLWithPath: sqlitePath as String)

    var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
    var error: NSError? = nil

    var failureReason = "There was an error creating or loading the application's saved data."
    let mOptions = [NSPersistentStoreUbiquitousContentNameKey: "AppNameCloud", NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption: true] as [String : Any]
    do {
        try coordinator!.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: mOptions)
    } catch var error1 as NSError {
        error = error1
        coordinator = nil
        // Report any error we got.
        var dict = [String: AnyObject]()
        dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data" as AnyObject?
        dict[NSLocalizedFailureReasonErrorKey] = failureReason as AnyObject?
        dict[NSUnderlyingErrorKey] = error
        error = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)

        // Replace this with code to handle the error appropriately.
        // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
        NSLog("Unresolved error \(error), \(error!.userInfo)")
        abort()
    } catch {
        fatalError()
    }

    return coordinator

Answer 1

Migration is what I'd do. Removing the ubiquitous content key makes Core Data load a different persistent store. Since it's new and empty, your existing data isn't there.

What you'd do is load the existing iCloud data store, then use the migratePersistentStore(_:to:options:withType:) method on NSPersistentStoreCoordinator to move all of the data to a non-iCloud store. When that finishes, start using the new store file.