Swift 3 Core Data Forced Downcasting to NSManagedObject Subclass

Question

So I've been learning and working with CoreData, and I've been very frustrated by the following problem. When I start my App, I want to fetch my CoreData as the custom NSManagedObject subclass that I've created. But the forced down casting never works. I've followed the Apple guide.

My data is the following. Below is the custom NSManagedObject subclass:

import UIKit
import CoreData
@objc(StudentUniversityData)

class UniversityData: NSManagedObject {
    @NSManaged var universityName:String
    @NSManaged var chineseName:String
    @NSManaged var bottomReadingPercentile:NSNumber
    @NSManaged var bottomMathPercentile:NSNumber
    @NSManaged var topReadingPercentile:NSNumber
    @NSManaged var topMathPercentile:NSNumber
}

Here is the code I've created:

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    let appDelegate = UIApplication.shared.delegate as! AppDelegate
    let managedContext = appDelegate.managedObjectContext
    let studentUniversityFetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "StudentUniversityData")
    studentUniversityFetchRequest.returnsObjectsAsFaults = false    
    do {
        let studentUniversityResults = try managedContext.fetch(studentUniversityFetchRequest)
        savedUniversities = studentUniversityResults as! [UniversityData] // the problem is HERE; this part never works
    } catch let error as NSError {
        print ("Could not fetch \(error), \(error.userInfo)")
    }
}

Here is one picture of my CoreData entity.

Here is another picture of my CoreData entity

No matter what I try to do, the savedUniversities property is always nil.

Also, I read that having multiple targets will screw up the code. So I made sure that all my classes only have one target (I took out the tests and UItests target membership). Still doesn't work.

Sorry if this isn't very clear, as I'm very tired and have worked on this problem for hours (without any progress). I've read many questions on Stack Overflow, like:

Unable to find specific subclass of NSManagedObject

CoreData: warning: Unable to load class named

Core Data: Could not cast value of type 'MyType_MyType_2' to MyType

But I'm still stuck.

Answer 1

So I was able to solve my problem after another half-day.

What I did was rename my Core Data entity to "UniversityData". That made it match the NSManagedObject subclass "UniversityData."

Everything works after the names match.

It seems that a lot of Core Data only works if the names match exactly with everything in your subclasses.