从 Firebase 打印所有 Children 列 - iOS Swift 4

Question

我的用户有2条记录table

下面这段代码

let fcmTokenRef = Database.database().reference().root.child("users").child(id!).child("fcmToken")
fcmTokenRef.observe(DataEventType.value, with: { (snapshot) in
    print(">>",snapshot)
})

会打印出child

的token

如何调整我的代码以打印 all 我所有 children 的代币？

Answer 1

您请求的是一次性读取，因此您只读取了一次数据。您需要使用 .childAdded

试试这个：

let fcmTokenRef = Database.database().reference().child(“users”)
    fcmTokenRef.observe(.childAdded, with: { (snapshot) in
    print(">>",snapshot)
     guard let data = snapshot as? NSDictionary else {return}
     var each_token = data[“fcmToken”] as? String
     print(“all tokens: \(each_token!)”)
})

@puf 说了一些非常重要的话：

The child_added event fires for each matching child under the node that you query. If there are no matching children, it will not fire.

Answer 2

你可以试试

let fcmTokenRef = Database.database().reference().root.child("users").observe(DataEventType.value, with: { (snapshot) in 
      print(">>",snapshot)

      let dic = snapshot.value as! [String:[String:Any]]
      Array(dic.values).forEach { 
        let str = [=10=]["fcmToken"] as! String
        print(str)
     }
})

从 Firebase 打印所有 Children 列 - iOS Swift 4

Print All Children Columns from Firebase - iOS Swift 4

ios

firebase

swift

firebase-realtime-database

swift3