这段代码适用于iOS 9及以下版本

class func deleteAllRecords(in entity : String) // entity = Your_Entity_Name
    {

        let context = CoreDataStack.getContext() // Note:- Replace your context here with CoreDataStack.getContext()
        let deleteFetch = NSFetchRequest<NSFetchRequestResult>(entityName: entity)
        if #available(iOS 9, *)
        {
            let deleteRequest = NSBatchDeleteRequest(fetchRequest: deleteFetch)
            do
            {
                try context.execute(deleteRequest)
                try context.save()
            }
            catch
            {
                print("There was an error:\(error)")
            }
        }
        else
        {
            do{
                let deleteRequest = try context.fetch(deleteFetch)
                for anItem in deleteRequest {
                    context.delete(anItem as! NSManagedObject)
                }
            }
            catch
            {
                print("There was an error:\(error)")
            }
        }
        CoreDataStack.saveContext() // Note:- Replace your savecontext here with CoreDataStack.saveContext()
    }

对于Swift 2.0:

class func clearCoreData(entity:String) {
  let fetchRequest = NSFetchRequest()
  fetchRequest.entity = NSEntityDescription.entityForName(entity, inManagedObjectContext: moc!)
  fetchRequest.includesPropertyValues = false
  do {
    if let results = try moc!.executeFetchRequest(fetchRequest) as? [NSManagedObject] {
      for result in results {
        moc!.deleteObject(result)
      }

      try moc!.save()
    }
  } catch {
    LOG.debug("failed to clear core data")
  }
}

一个很好的答案已经贴出来了，这只是一个推荐!

一个好方法是添加一个类别到NSManagedObject和实现一个方法，就像我做的:

头文件(例如NSManagedObject+Ext.h)

@interface NSManagedObject (Logic)

+ (void) deleteAllFromEntity:(NSString*) entityName;

@end

代码文件:(例如NSManagedObject+Ext.m)

@implementation NSManagedObject (Logic)

+ (void) deleteAllFromEntity:(NSString *)entityName {
    NSManagedObjectContext *managedObjectContext = [AppDelegate managedObjectContext];
    NSFetchRequest * allRecords = [[NSFetchRequest alloc] init];
    [allRecords setEntity:[NSEntityDescription entityForName:entityName inManagedObjectContext:managedObjectContext]];
    [allRecords setIncludesPropertyValues:NO];
    NSError * error = nil;
    NSArray * result = [managedObjectContext executeFetchRequest:allRecords error:&error];
    for (NSManagedObject * profile in result) {
        [managedObjectContext deleteObject:profile];
    }
    NSError *saveError = nil;
    [managedObjectContext save:&saveError];
}

@end

．.． 你唯一要做的就是从应用程序委托获取managedObjectContext，或者你在哪里都有它;)

之后你可以这样使用它:

[NSManagedObject deleteAllFromEntity:@"EntityName"];

进一步的优化可以是删除entityname的参数，而从clazzname获取名称。这将导致使用:

[ClazzName deleteAllFromEntity];

一个更干净的impl(作为NSManagedObjectContext的类别):

@implementation NSManagedObjectContext (Logic)

- (void) deleteAllFromEntity:(NSString *)entityName {
    NSFetchRequest * allRecords = [[NSFetchRequest alloc] init];
    [allRecords setEntity:[NSEntityDescription entityForName:entityName inManagedObjectContext:self]];
    [allRecords setIncludesPropertyValues:NO];
    NSError * error = nil;
    NSArray * result = [self executeFetchRequest:allRecords error:&error];
    for (NSManagedObject * profile in result) {
        [self deleteObject:profile];
    }
    NSError *saveError = nil;
    [self save:&saveError];
}

@end

那时的用法:

[managedObjectContext deleteAllFromEntity:@"EntityName"];

在Swift 2.0中:

func deleteAllData(entity: String)
{
    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
    let managedContext = appDelegate.managedObjectContext
    let fetchRequest = NSFetchRequest(entityName: entity)
    fetchRequest.returnsObjectsAsFaults = false

    do 
    {
        let results = try managedContext.executeFetchRequest(fetchRequest)
        for managedObject in results
        {
            let managedObjectData:NSManagedObject = managedObject as! NSManagedObject
            managedContext.deleteObject(managedObjectData)
        }
    } catch let error as NSError {
        print("Detele all data in \(entity) error : \(error) \(error.userInfo)")
    }
}

更干净和通用一点:添加这个方法:

- (void)deleteAllEntities:(NSString *)nameEntity
{
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:nameEntity];
    [fetchRequest setIncludesPropertyValues:NO]; //only fetch the managedObjectID

    NSError *error;
    NSArray *fetchedObjects = [theContext executeFetchRequest:fetchRequest error:&error];
    for (NSManagedObject *object in fetchedObjects)
    {
        [theContext deleteObject:object];
    }

    error = nil;
    [theContext save:&error];
}

Dave Delongs的Swift 2.0回答让我崩溃了(在iOS 9中)

但这个方法奏效了:

let fetchRequest = NSFetchRequest(entityName: "Car")
let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)

    do {
        try managedObjectContext.executeRequest(deleteRequest)
        try managedObjectContext.save()
    }
    catch let error as NSError {
       // Handle error
    }