如何获取所有孩子的firebase实时数据库？

{
  "children": {
    "child1": {
      "name": "Alice",
      "age": 5
    },
    "child2": {
      "name": "Bob",
      "age": 8
    },
    "child3": {
      "name": "Charlie",
      "age": 3
    }
  }
}

var databaseRef = firebase.database().ref("children");

databaseRef.on("value", function(snapshot) {
  snapshot.forEach(function(childSnapshot) {
    var childKey = childSnapshot.key;
    var childData = childSnapshot.val();
    console.log("Child key: " + childKey);
    console.log("Child data: " + JSON.stringify(childData));
  });
});