json - swift 。如何从Firebase数据库的快照中获取特定数据

Question

好的，我正在从 Firebase 数据库接收快照，这是我的代码以及我正在接收的内容:

rootRef.child("Battles").queryOrderedByChild("Player1").queryEqualToValue(CurrentFBID).observeSingleEventOfType(.Value, withBlock: { snap in
    if (snap.value is NSNull) {
        print("none")
    } else {
        print(snap.value)
    }
})

接收:

{

"04361D33-AC99-4795-BB9A-0B0879882251" =

{

BattleUUID = "04361D33-AC99-4795-BB9A-0B0879882251";

Player1 = 10210238266903604;

Player2 = 12121212121212;

Score = "0-0";

Turn = 1;

};

}

我的 JSON 树:

{
  "Battles" : {
    "04361D33-AC99-4795-BB9A-0B0879882251" : {
      "BattleUUID" : "04361D33-AC99-4795-BB9A-0B0879882251",
      "Player1" : "10210238266903604",
      "Player2" : "12121212121212",
      "Score" : "0-0",
      "Turn" : "1"
    },
    "07261D43-GC59-4795-BB9A-0B0871635751" : {
      "BattleUUID" : "04361D33-AC99-4795-BB9A-0B0879882251",
      "Player1" : "1342536342535",
      "Player2" : "1524343564",
      "Score" : "3-1",
      "Turn" : "5"
    }
  }
}

如何拆分该数据，例如:

let player1 = snap.Player1.value
let player2 = snap.Player2.value
let battleUUID = snap.BattleUUID.value
let score = snap.Score.value
let turn = snap.Turn.value

Answer 1

您将立即收到所有数据。 snap 包含 children，每个 child 都属于特定的战斗。要获取与每个子项相对应的数据，您必须对 snap 的 children 进行迭代，如下所示:

for item in snap.children {
    let player1 = item.value?["Player1"] as! String
    let player2 = item.value?["Player2"] as! String
    let battleUUID = item.value?["BattleUUID"] as! String
    let score = item.value?["Score"] as! String
    let turn = item.value?["Turn"] as! String
}