如何使用react native从firebase实时数据库中获取数据，这些数据库是随机键的子级？

npm install firebase

import firebase from 'firebase';

const firebaseConfig = {
  apiKey: "YOUR_API_KEY",
  authDomain: "YOUR_AUTH_DOMAIN",
  databaseURL: "YOUR_DATABASE_URL",
  projectId: "YOUR_PROJECT_ID",
  storageBucket: "YOUR_STORAGE_BUCKET",
  messagingSenderId: "YOUR_MESSAGING_SENDER_ID",
  appId: "YOUR_APP_ID"
};

firebase.initializeApp(firebaseConfig);

- users
  - randomKey1
    - name: "John"
    - age: 25
  - randomKey2
    - name: "Jane"
    - age: 30

firebase.database().ref('users').once('value')
  .then(snapshot => {
    snapshot.forEach(childSnapshot => {
      const key = childSnapshot.key;
      const childData = childSnapshot.val();
      console.log("Key: " + key);
      console.log("Data: " + JSON.stringify(childData));
    });
  })
  .catch(error => {
    console.log("Error: " + error.message);
  });