保护和选择谷歌FireStore中的分层数据

// 创建一个集合引用
const usersCollection = firestore.collection('users');

// 添加一个新用户文档
usersCollection.add({
  name: 'John Doe',
  age: 30,
  address: {
    street: '123 Main St',
    city: 'Anytown',
    zip: '12345'
  },
  orders: firestore.collection('orders').doc() // 嵌套集合引用
}).then(docRef => {
  console.log('User added with ID: ', docRef.id);
}).catch(err => {
  console.error('Error adding user: ', err);
});

// 查询用户及其订单
usersCollection.where('name', '==', 'John Doe').get().then(querySnapshot => {
  querySnapshot.forEach(doc => {
    console.log(doc.id, ' => ', doc.data());
    doc.ref.collection('orders').get().then(ordersSnapshot => {
      ordersSnapshot.forEach(orderDoc => {
        console.log('Order ID: ', orderDoc.id, ' => ', orderDoc.data());
      });
    });
  });
});