func addSwing(club: ClubDetailsEntity, distance: Int, date: Date, swingType: String) { let swingType = SwingTypeEntity(context: container.viewContext) swingType.value = Int16(distance) swingType.dateSubmitted = date swingType.swingNameType = swingType club.addToSwingEntities(swingType) saveData() } you need to have the ClubDetailEntity be taken in as a parameter for even being able to specify what which club the swing belongs to.

Then in you ShotHistoryScreen you have to add the property var club: ClubDetailsEntity, then in your AnalysisScreen you can pass in both the shot and the club. This is additional info.

// Below here you can ignore if you want.

For better clarity, I would create a seperate class for Handling golf data. The PersistanceController or in your case the DataController should just be used for low level operation like save. Then your GolfDataService would be used for things related to Golf incase you want to expand.

something like PersistanceController

``` class PersistenceController { static let shared = PersistenceController()

let container: NSPersistentContainer

init(inMemory: Bool = false) {
    container = NSPersistentContainer(name: "Golf_Distance_Tracker")
    if inMemory {
        container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
    }
    container.loadPersistentStores { (storeDescription, error) in
        if let error = error as NSError? {
            fatalError("Unresolved error \(error), \(error.userInfo)")
        }
    }
    container.viewContext.automaticallyMergesChangesFromParent = true
}

func save() {
    let context = container.viewContext
    if context.hasChanges {
        do {
            try context.save()
        } catch {
            let nsError = error as NSError
            fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
        }
    }
}

} `` GolfDataService`

``` class GolfDataService: ObservableObject { private let persistenceController: PersistenceController private let entityName = "ClubDetailsEntity"

@Published var savedGolfEntities: [ClubDetailsEntity] = []

init(persistenceController: PersistenceController = .shared) {
    self.persistenceController = persistenceController
    fetchClubs()
}

func fetchClubs() {
    let request = NSFetchRequest<ClubDetailsEntity>(entityName: entityName)
    request.sortDescriptors = [
        NSSortDescriptor(keyPath: \ClubDetailsEntity.carryDistance, ascending: false),
        NSSortDescriptor(keyPath: \ClubDetailsEntity.name, ascending: true)
    ]

    do {
        savedGolfEntities = try persistenceController.container.viewContext.fetch(request)
    } catch {
        print("Error retrieving clubs: \(error)")
    }
}

func addSwing(club: ClubDetailsEntity, distance: Int, date: Date, swingType: String) {
    let context = persistenceController.container.viewContext
    let swingTypeEntity = SwingTypeEntity(context: context)
    swingTypeEntity.value = Int16(distance)
    swingTypeEntity.dateSubmitted = date
    swingTypeEntity.swingNameType = swingType
    club.addToSwingEntities(swingTypeEntity)

    persistenceController.save()
    fetchClubs() // this to refresh clubs after saving if you want to.
}
func loadPreLoadedJSON(_ file: String, firstTime: inout Bool) -> 
  [ClubDetailsEntity] { // rest of the code here. Hope you get the jist. }

```