ios - 为什么它会覆盖数据而不是在 firebase 中添加更多数据？

Question

我很想知道为什么当用户输入新数据时数据会被覆盖，我希望它向它添加更多数据而不是覆盖它的数据也想知道怎么读提前谢谢你

 let oDB = Database.database().reference().child("Data")
    let oDictionary = ["Data1" : strange.text! , "Data2" : stranger.text!]
    let uid = Auth.auth().currentUser?.uid
    oDB.child(uid!).setValue(oDictionary) {

        (error, reference) in
        if error != nil{
            print(error!)
        } else  {
            print("saved Sucessfully")
            self.navigationController?.popViewController(animated: true)

        }
    }

 //In another ViewController
 func updateRequest() {
    let uid = Auth.auth().currentUser?.uid
    let yDb = Database.database().reference().child("Data").child(uid!)
    postDb.observeSingleEvent(of: .value) { (snapShot) in
        if let snapShotValue = snapShot.value as? Dictionary<String, String> {

        let text = snapShotValue["Data1"]!
        let case = snapShotValue["Data2"]!


        let data = Data()
        data.s= text
        data.y = case

        self.array.append(data)
        self.table.reloadData()
    }
    }
}

Answer 1

setValue 覆盖旧内容，你可能需要childByAutoId

oDB.child(uid!).childByAutoId().setValue(oDictionary) {

    (error, reference) in
    if error != nil{
        print(error!)
    } else  {
        print("saved Sucessfully")
        self.navigationController?.popViewController(animated: true)

    }

这将给出这个结构

Data 
  > uid
    > someKey1             <<<< auto generated 
        Data1:"---"
        Data2:"---"
    > someKey2             <<<< auto generated 
        Data1:"---"
        Data2:"---"

---

阅读

 //In another ViewController
 func updateRequest() {
    let uid = Auth.auth().currentUser?.uid
    let yDb = Database.database().reference().child("Data").child(uid!)
    postDb.observeSingleEvent(of: .value) { (snapShot) in
        if let snapShotValue = snapShot.value as? [String:[String:String]] {

          Array(snapShotValue.values).forEach {
            let data = Data()
            data.s= $0["Data1"]!
            data.y = $0["Data2"]! 
            self.array.append(data)
         }

        self.table.reloadData()
    }
    }
}