firebase.database().ref list code example

Example 1: firebase orderbychild update

database.ref('/app/posts')
  .orderByChild('material')
  .equalTo(materialName)
  .once('value', function (snapshot) {
    snapshot.forEach(function(child) {
      child.ref.update({material: false});
    });
});

Example 2: how to push multiple data to different parents in a single request in firebase

var ref = new Firebase("https://.firebaseio.com");
// Generate a new push ID for the new post
var newPostRef = ref.child("posts").push();
var newPostKey = newPostRef.key();
// Create the data we want to update
var updatedUserData = {};
updatedUserData["user/posts/" + newPostKey] = true;
updatedUserData["posts/" + newPostKey] = {
  title: "New Post",
  content: "Here is my new post!"
};
// Do a deep-path update
ref.update(updatedUserData, function(error) {
  if (error) {
    console.log("Error updating data:", error);
  }
});