ios - Firebase数据库-如何从多个子节点获取子值并将其存储在Swift字典中

我的数据库结构如下:

"routines": {
  "users unique identifier": {
    "routine unique identifier": {
      "routine_name": "routine name",
      "routine_create_date": "routine created date",
      "exercises": {
        "exercise name": {
          "Sets": "number of sets"
        }
      }
    }
  }
}

检索数据时，我想将每个routine存储为一个对象，以加载到UITableView中。我使用的例程结构是:

struct Routine {
  var routineName: String!
  var routineExercisesAndSets: [String:Int]!
}

如何从中检索值，以便对于每个Routine模型，我都可以拥有Routine(routineName: "Legs", routineExercisesAndSets: ["Squats":4,"Lunges":4,"Calf Raises":4])，其中练习词典为exercise name:number of sets。

我目前使用的是其他结构，几乎可以通过以下方法获得所需的结果:

let ref = FIRDatabase.database().reference().child("routines").child(userId)
var routineTemp = Routine()
ref.observe(.childAdded, with: { (snapshot) in
    if let dictionary = snapshot.value as? [String : AnyObject] {
        routineTemp.routineName = dictionary["routineName"] as! String
        let enumerator = snapshot.childSnapshot(forPath: "exercises").children
        var exercisesAndSets = [String:Int]()
        while let item = enumerator.nextObject() as? FIRDataSnapshot {
            exercisesAndSets[item.key] = item.value! as? Int
        }
        routineTemp.routineExercisesAndSets = exercisesAndSets
        print(routineTemp)
    }
} , withCancel: nil)

最佳答案

我设法使用以下代码获取每个练习的值及其各自的numberOfSets:

guard let userId = FIRAuth.auth()?.currentUser?.uid else {
    return
}

let ref = FIRDatabase.database().reference().child("routines").child(userId)
var routineTemp = Routine()
var exercisesAndSets = [String:Int]()
ref.observe(.childAdded, with: { (snapshot) in

    if let dictionary = snapshot.value as? [String : AnyObject] {

        routineTemp.routineName = dictionary["routineName"] as! String
        let enumerator = snapshot.childSnapshot(forPath: "exercises").children

        while let item = enumerator.nextObject() as? FIRDataSnapshot {

            exercisesAndSets[item.key] = item.childSnapshot(forPath: "numberOfSets").value! as? Int
        }

    }

    routineTemp.routineExercisesAndSets = exercisesAndSets

    self.routines.append(routineTemp)

    DispatchQueue.main.async {
        self.tableView.reloadData()
    }

} , withCancel: nil)

如果还有其他人遇到类似的问题，我希望这有助于提供一种获取值的方法的想法。