只能在Firebase中获取特定的孩子-onlygetspecificchildsinFirebase

4  

Not in that data structure. When you read a tree in Firebase, you get all the children.

不在那个数据结构中。当您在Firebase中阅读树时，您将获得所有孩子。

If you want just the messages, you'd have to maintain a separate data structure, which is easy using mutli-path updates.

如果您只想要消息，则必须维护一个单独的数据结构，这很容易使用多路径更新。

{
   "chatMessages": {
      "-JZvOzp0L1ccuBt2TVN7": "hello",
      "-JZvPneW5et0_EVRvL5g": "hai"
   }
}

Then you can sync all just the children:

然后你可以同步所有孩子：

var ref = new Firebase("");
var messagesRef = ref.child("chatMessages");
messagesRef.on("value", (data) => console.log(data));