我经常使用的另一种方法(除了删除批处理请求)(基于应用程序需求)是重置持久存储。iOS 10+和Swift的实现如下所示(假设你有一个CoreDataManager类):

let persistentContainer: NSPersistentContainer = {
    let container = NSPersistentContainer(name: "<Data-Model-Name>“)
    container.loadPersistentStores(completionHandler: { (storeDescription, err) in
        if let err = err {
            fatalError("loading of store failed: \(err)")
        }
    })
    return container
}()

func resetPersistentStore() {

    if let persistentStore = persistentContainer.persistentStoreCoordinator.persistentStores.last {
        let storeURL = persistentContainer.persistentStoreCoordinator.url(for: persistentStore)

        do {
            try persistentContainer.persistentStoreCoordinator.destroyPersistentStore(at: storeURL, ofType: NSSQLiteStoreType, options: nil)
        } catch {
            print("failed to destroy persistent store:", error.localizedDescription)
        }

        do {
            try persistentContainer.persistentStoreCoordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: storeURL, options: nil)
        } catch {
            print("failed to re-add persistent store:", error.localizedDescription)
        }
    }

}

这种方法的一个优点是，它更直接，特别是当您在核心数据中有大量实体的数据记录时。在这种情况下，删除批处理请求将占用大量内存。

我从一个HomeViewController类的一个按钮事件的核心数据中删除所有数据: 这篇文章对我帮助很大，我想我也会有所贡献。

-(IBAction)buttonReset:(id)sender
{
    NSLog(@"buttonReset Pressed");

    //Erase the persistent store from coordinator and also file manager.
    NSPersistentStore *store = [self.persistentStoreCoordinator.persistentStores lastObject];
    NSError *error = nil;
    NSURL *storeURL = store.URL;
    [self.persistentStoreCoordinator removePersistentStore:store error:&error];
    [[NSFileManager defaultManager] removeItemAtURL:storeURL error:&error];


    NSLog(@"Data Reset");

    //Make new persistent store for future saves   (Taken From Above Answer)
    if (![self.persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {
        // do something with the error
    }

}

注意，为了调用self。我在主视图控制器中声明了一个属性。(不要担心我用来保存和加载的managedObjectContext。)

@property (nonatomic, retain) NSManagedObjectContext        *   managedObjectContext;
@property (nonatomic, retain) NSPersistentStoreCoordinator  *   persistentStoreCoordinator;

然后在AppDelegate ApplicationDidFinishLaunching下面创建一个HomeViewController:

homeViewController = [[HomeViewController alloc] initWithNibName:@"HomeViewController" bundle:nil];
homeViewController.managedObjectContext = self.managedObjectContext;
homeViewController.persistentStoreCoordinator = self.persistentStoreCoordinator;

这里是清洗核心数据的组合解决方案。

- (void)deleteAllObjectsInCoreData
{
    NSArray *allEntities = self.managedObjectModel.entities;
    for (NSEntityDescription *entityDescription in allEntities)
    {
        NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
        [fetchRequest setEntity:entityDescription];

        fetchRequest.includesPropertyValues = NO;
        fetchRequest.includesSubentities = NO;

        NSError *error;
        NSArray *items = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];

        if (error) {
                NSLog(@"Error requesting items from Core Data: %@", [error localizedDescription]);
            }

        for (NSManagedObject *managedObject in items) {
            [self.managedObjectContext deleteObject:managedObject];
        }

        if (![self.managedObjectContext save:&error]) {
            NSLog(@"Error deleting %@ - error:%@", entityDescription, [error localizedDescription]);
        }
    }  
}

Swift 4/5, iOS 9+

重新构建整个CoreData SQLite文件将确保擦除所有数据，因此删除所有实体。只需调用deleteAndRebuild()。

class CoreDataStack {
    // Change this
    static let datamodelName = "ProjectName"
    static let storeType = "sqlite"

    static let persistentContainer = NSPersistentContainer(name: datamodelName)
    private static let url: URL = {
        let url = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0].appendingPathComponent("\(datamodelName).\(storeType)")

        assert(FileManager.default.fileExists(atPath: url.path))

        return url
    }()

    static func loadStores() {
        persistentContainer.loadPersistentStores(completionHandler: { (nsPersistentStoreDescription, error) in
            if let error = error {
                fatalError(error.localizedDescription)
            }
        })
    }

    static func deleteAndRebuild() {
        try! persistentContainer.persistentStoreCoordinator.destroyPersistentStore(at: url, ofType: storeType, options: nil)

        loadStores()
    }
}

iOS 10和Swift 3

假设您的实体名称是“Photo”，并且您创建了一个CoreDataStack类…

 func clearData() {
        do {            
            let context = CoreDataStack.sharedInstance.persistentContainer.viewContext
            let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Photo")
            do {
                let objects  = try context.fetch(fetchRequest) as? [NSManagedObject]
                _ = objects.map{$0.map{context.delete($0)}}
                CoreDataStack.sharedInstance.saveContext()
            } catch let error {
                print("ERROR DELETING : \(error)")
            }
        }
    }

这里有一个很好的教程，教你如何使用CoreData以及如何使用这个方法。 https://medium.com/compileswift/parsing-json-response-and-save-it-in-coredata-step-by-step-fb58fc6ce16f#.1tu6kt8qb

迅速的解决方案:

class func deleteAllManagedObjects() {

        let modelURL = NSBundle.mainBundle().URLForResource("some string", withExtension: "mom")
        let mom = NSManagedObjectModel(contentsOfURL: modelURL)

        for entityName in mom.entitiesByName.keys {
            let fr = NSFetchRequest(entityName: entityName as String)
            let a = Utility.managedObjectContext().executeFetchRequest(fr, error: nil) as [NSManagedObject]
            for mo in a {
                Utility.managedObjectContext().deleteObject(mo)
            }
        }

        Utility.managedObjectContext().save(nil)
    }