使用Swift从Firebase中获取所有子级的数据

Question

我有一个Firebase实时数据库。看起来像这样：

这是我的代码：

ref.child("2").observeSingleEvent(of: .value, with: { snapshot in

        guard let dict = snapshot.value as? [String:Any] else {
            print("Error")
            return
        }
        let latitude = dict["Latitude"] as Any
        let longtitude = dict["Longtitude"] as Any
        print(longtitude)
        print(latitude)
    })

我的问题是我的代码仅从名为2的孩子那里检索数据。如何使它从所有孩子那里检索数据？

如果您有任何疑问，请告诉我。感谢您的帮助！

Answer 1

您需要听ref

ref.observeSingleEvent(of: .value, with: { snapshot in

        guard let dict = snapshot.value as? [String:[String:Any]] else {
            print("Error")
            return
        }
        Array(dict.values).forEach {
           let latitude = $0["Latitude"] as? String
           let longtitude = $0["Longtitude"] as? Int
           print(longtitude)
           print(latitude)
        }
})

Answer 2

您将要在JSON中将观察者附加上一层，然后在子节点上循环：

ref.observeSingleEvent(of: .value) { snapshot in
    for case let child as FIRDataSnapshot in snapshot.children {
        guard let dict = child.value as? [String:Any] else {
            print("Error")
            return
        }
        let latitude = dict["Latitude"] as Any
        let longtitude = dict["Longtitude"] as Any
        print(longtitude)
        print(latitude)
    }
}

取自Iterate over snapshot children in Firebase的循环语法，另请参见How do I loop all Firebase children at once in the same loop?和Looping in Firebase