node.js - 从更改快照键中检索特定数据

Question

我正在尝试从不断更新的孩子的 Firebase 数据中检索 JSON 数据。每次提交新数据时，快照键都会更改。（使用 sparkpost 将数据发送到 firebase）。我试图找出一种方法来构造我的检索，以便它可以从最新的键中获取。

var ref = new Firebase("https://watspark.firebaseio.com/raw-events/");
var _url = ('https://watspark.firebaseio.com/raw-events/');


// Retrieve new posts as they are added to our database
ref.on("child_added", function(snapshot, prevChildKey) {
  var newPost = snapshot.val();
  console.log(snapshot.val());

  // console.log("text: "  + newPost.text);
  // console.log("Title: " + newPost.title);
  // console.log("Previous Post ID: " + prevChildKey);
  // var fireUrl = ("https://watspark.firebaseio.com/raw-events/" + snapshot.val() + "/0/msys/relay_message/content");
  //  var bigBoy = new Firebase(fireUrl);
  //   console.log("text: " + bigBoy.text);

  var param = snapshot.key();
  console.log(param);
});

ref.orderByChild("0/mysys/relay_message/content/text").on("child_added",   function(snapshot) {
  console.log(snapshot.key() + "was" + snapshot.val().text);
});

我的 JSON 数据结构如下：

   snapshot.val();
   {
     0 {
       mysys{
         relay_message{
           content

我该怎么做呢？谢谢

Answer 1

通过这样做，我可以给最近的孩子打电话：

ref.orderByKey().limitToLast(1).on("child_added", function(snapshot) {
  var child = snapshot.val();
  console.log(snapshot.key());
  var snapKey = '' + snapshot.key();

  snapshot.child("0/msys/relay_message/content/").forEach(function(snap){
    console.log('snap ' + snap.val());
    if(snap.key() === 'text'){
      watsonInput = snap.val();
    }
  });

  snapshot.child("0/msys/relay_message/").forEach(function(snap){
    console.log('email: ' + snap.val());
    if(snap.key() === 'msg_from'){
      email = snap.val();
    }
    //call to remove current snapshotKey
  });