删除多个实体中的核心数据条目

Swift编程的新手，并且在使用Core Data时遇到了麻烦 . 我试图删除通过Int64号码链接到主实体的2个其他实体中的条目 .

GameInfo - 主实体 . 有比赛号码，球队名称，得分，日期属性等.HomeSubstitution＆AwaySubstitution-两队换人 . 每场比赛可以超过一场 . 将游戏编号作为每个记录集中的属性 .

我已经与实体 Build 了关系并制作了删除规则= Cascade .

图数据模型：core data model

我可以删除删除GameInfo记录集但它已经消失，但HomeSubstitution和AwaySubstitution记录仍然存在 . 当您开始新游戏时，旧数据现在链接到新游戏 . 即，去查看游戏，并且用新游戏显示已删除的GameInfo中的替换 .

这是我的代码 .

@objc lazy var fetchedResultsController: NSFetchedResultsController<GameInfo> = {
    let fetchRequest: NSFetchRequest<GameInfo> = GameInfo.fetchRequestGame()
    fetchRequest.sortDescriptors = [NSSortDescriptor(key: "gameNumber", ascending: true)]
    let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.persistentContainer.viewContext, sectionNameKeyPath: nil, cacheName: nil)
    fetchedResultsController.delegate = self

    return fetchedResultsController
}()

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
    if editingStyle == .delete {
        // Fetch game
        let gameRow = fetchedResultsController.object(at: indexPath)
        let gameNumberDelete = gameRow.gameNumber
        print("game row to delete: \(gameRow)")
        print("game number to delete: \(String(describing: gameNumberDelete))") //This works and I get the game number
        // Delete game
        gameRow.managedObjectContext?.delete(gameRow)
    }
}

我尝试使用类似的代码执行fetchedHomeController和fetchedAwayController，引用不同的实体和NSPredicate（在其他类中用于审查游戏）的fetchedResultsController，但我得到错误抛出 .

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
    if editingStyle == .delete {
        // Fetch game
        let gameRow = fetchedResultsController.object(at: indexPath)
        let gameNumberDelete = gameRow.gameNumber
        print("game row to delete: \(gameRow)")
        print("game number to delete: \(String(describing: gameNumberDelete))")
        // Delete game
        gameRow.managedObjectContext?.delete(gameRow)
        //Delete home substitutions
        let fetchRequestHome = NSFetchRequest<NSFetchRequestResult>(entityName: "HomeSubstitution")
        fetchRequestHome.predicate = NSPredicate(format: "homeGameLink == %i", gameNumberDelete)
        fetchRequestHome.returnsObjectsAsFaults = false

        print("fetchRequestHome: \(fetchRequestHome)")

        do {
            try self.fetchedHomeController.performFetch()
            let homeGameDelete = fetchedHomeController.object(at: indexPath)
            print("homeGameDelete: \(homeGameDelete)")
            homeGameDelete.managedObjectContext?.delete(homeGameDelete) //Error here to do with NSFetchedResultsController.
        } catch {
            let fetchError = error as NSError
            print("Unable to Perform Fetch Request")
            print("\(fetchError), \(fetchError.localizedDescription)")
        }
    }
}

我怀疑删除的数量超过了我选择的行数，NSFetchedResultsController将不允许它 .

编辑：全部搞清楚 . 使用Raj Joshi在Delete Object from Core Data中给出的例子 .

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
    if editingStyle == .delete {
        // Fetch game
        let mocGame = getContext()
        let gameRow = fetchedResultsController.object(at: indexPath)
        let gameNumberDelete = gameRow.gameNumber
        print("game row to delete: \(gameRow)")
        print("game number to delete: \(String(describing: gameNumberDelete))")
        // Delete game
        gameRow.managedObjectContext?.delete(gameRow)
        do {
            try mocGame.save()
            print("saved Game Deletion!")
        } catch let error as NSError  {
            print("Could not save \(error), \(error.userInfo)")
        } catch {

        }
        //Delete substitutions based on gameNumber
        deleteHomeGameData(link: gameNumberDelete)
        deleteAwayGameData(link: gameNumberDelete)

    }
}

func deleteHomeGameData(link: Int64) -> Void{

    let mocHome = getContext()
    let fetchRequestHome = NSFetchRequest<NSFetchRequestResult>(entityName: "HomeSubstitution")
    fetchRequestHome.predicate = NSPredicate(format: "homeGameLink == %i", link)

    do {
        let result = try? mocHome.fetch(fetchRequestHome)
        let resultData = result as! [HomeSubstitution]

        //Loop through substitutions and delete.
        for object in resultData {
            mocHome.delete(object)
        }

        do {
            try mocHome.save()
            print("saved Home substitution deletion!")
        } catch let error as NSError  {
            print("Could not save \(error), \(error.userInfo)")
        } catch {

        }
    }
}

func deleteAwayGameData(link: Int64) -> Void{

    let mocAway = getContext()
    let fetchRequestAway = NSFetchRequest<NSFetchRequestResult>(entityName: "AwaySubstitution")
    fetchRequestAway.predicate = NSPredicate(format: "awayGameLink == %i", link)

    do {
        let result = try? mocAway.fetch(fetchRequestAway)
        let resultData = result as! [AwaySubstitution]

        //Loop through substitutions and delete.
        for object in resultData {
            mocAway.delete(object)
        }

        do {
            try mocAway.save()
            print("saved Away substitution deletion!")
        } catch let error as NSError  {
            print("Could not save \(error), \(error.userInfo)")
        } catch {

        }
    }
}

func getContext () -> NSManagedObjectContext {
    let appDelegate = UIApplication.shared.delegate as! AppDelegate
    return appDelegate.persistentContainer.viewContext
}