Firebase如何使用子集合筛选集合

const admin = require('firebase-admin');
admin.initializeApp({
  credential: admin.credential.applicationDefault(),
  databaseURL: 'https://<your-database-name>.firebaseio.com'
});

const db = admin.firestore();

async function getUsersWithSpecificOrder(orderId) {
  const usersRef = db.collection('users');
  const usersSnapshot = await usersRef.get();

  const usersWithOrder = [];

  for (const userDoc of usersSnapshot.docs) {
    const ordersRef = userDoc.ref.collection('orders');
    const ordersSnapshot = await ordersRef.where('orderId', '==', orderId).get();

    if (!ordersSnapshot.empty) {
      usersWithOrder.push(userDoc.data());
    }
  }

  return usersWithOrder;
}

getUsersWithSpecificOrder('specific-order-id')
  .then(users => {
    console.log('Users with specific order:', users);
  })
  .catch(error => {
    console.error('Error getting users:', error);
  });