ios - Firebase 中的简单查询

Question

我是 Swift 中 Firebase 的新手，我发现有更多人在同一条船上。我的想法是检索每个玩家的分数。Firebase 数据库是这样的:

在根引用上 (dbRef = FIRDatabase.database().reference())我的代码是这样做的:

dbRef.queryOrdered(byChild: "score").observeSingleEvent(of: .value) { (snap: FIRDataSnapshot) in
        for child in snap.children{
            print(child)
        }
    }

在终端中生成这些消息:

Snap (zfUNewjOCsQ5VCtSLFXSXLSFXtJ3) {
    addedByUser = "julio@gmail.com";
    score = 100;
}
Snap (yfJqO65qCwTTlgzrcw1ovmPgZ6l2) {
    addedByUser = "oswaldo@gmail.com";
    score = 1000;
}

如何获得分数以便在终端中打印的消息如下:

100

1000

提前致谢

Answer 1

您将使用 childSnapshotForPath 获得分数:

dbRef.queryOrdered(byChild: "score").observeSingleEvent(of: .value) { (snap: FIRDataSnapshot) in
    for child in snap.children{
        print((child as AnyObject).childSnapshot(forPath: "score").value)
    }
}

参见 https://firebase.google.com/docs/reference/ios/firebasedatabase/api/reference/Classes/FIRDataSnapshot#-childsnapshotforpath