核心数据仅向最后一个对象添加数据

Question

我正在尝试使用默认数据填充核心数据以进行测试，但是当我尝试通过获取请求访问它们时，创建的25个DataPoint对象不会将Meal对象存储在其.meal属性中。在保存之前，我已遍历DataPoint对象并打印了他们的.meal属性，该属性显示已成功为每个属性设置属性。但是，在我获取这些DataPoints时的保存之后，只有最后一个DataPoint包含其中的膳食设置。

     if User.currentUser == nil {

        let newUser = NSEntityDescription.insertNewObjectForEntityForName("User", inManagedObjectContext: managedObjectContext) as! User
        newUser.username = "Will"
        newUser.avatar_large = UIImagePNGRepresentation(UIImage(named: "Karl@3x.png")!)
        newUser.meals = NSSet()

        let newMeal = NSEntityDescription.insertNewObjectForEntityForName("Meal", inManagedObjectContext: managedObjectContext) as! Meal
        newMeal.title = "BURGER AND FRIES"
        newMeal.time = NSDate().dateByAddingTimeInterval(-24*60*60)
        newUser.meals = newUser.meals?.setByAddingObject(newMeal)

        var last = 150.0

        UINavigationBar.appearance().tintColor = UIColor.whiteColor()

        for i in 0..<25 {

            let dataPoint = NSEntityDescription.insertNewObjectForEntityForName("DataPoint", inManagedObjectContext: managedObjectContext) as! DataPoint
            dataPoint.time = newMeal.time.dateByAddingTimeInterval(Double(i) * 300.0)
            last += drand48() * 40 * (drand48() > 0.5 ? -1.0 : 1.0)
            dataPoint.value = NSNumber(double: last)
            dataPoint.meal = NSSet(object: newMeal)

        }

        do {

            try managedObjectContext.save()

        } catch {

            print("User Save Failed")

        }

    }