從NSFetchRequest將字典數組轉換為值數組

Question

我有一本字典，它是使用fetchRequest.resultType = .dictionaryResultType從NSFetchRequest返回的，返回的字典是[Any] ，看起來像以下內容：

teams [{
    team = Canadiens;
}, {
    team = "Maple Leafs";
}, {
    team = Penguins;
}]

我只想要一個值數組，例如[Canadiens, "Maple Leafs", Penguins"] ，如何將字典數組轉換為僅包含值的數組？

全取

func teamNames(managedContext: NSManagedObjectContext) {
    //print("\(self) -> \(#function)")

    let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Players")

    fetchRequest.fetchBatchSize = 8
    fetchRequest.propertiesToGroupBy = [#keyPath(Players.team)]
    fetchRequest.propertiesToFetch   = [#keyPath(Players.team)]
    fetchRequest.resultType          = .dictionaryResultType

    do {

        let fetchTeamNamesDictionary = try managedContext.fetch(fetchRequest)
        print("fetchTeamNamesDictionary \(fetchTeamNamesDictionary)")


    } catch let error as NSError {

        print("GoFetch|teamNames: Could not fetch. \(error), \(error.userInfo)")
    }


}

替代可接受的答案：

do {

    let fetchTeamNamesArray = try managedContext.fetch(fetchRequest)

    for array in fetchTeamNamesArray {

        let teamName = (array as AnyObject).value(forKey: "team") as! String

        teamNameArray.append(teamName)

    }

Answer 1

如您所知，結果的鍵和值是字符串，將結果強制向下轉換為[[String:String]]

let teamArray = try managedContext.fetch(fetchRequest) as! [[String:String]]

然后將字典映射到關鍵team價值

let teamNames = teamArray.map { $0["team"]! }