在flutter中组合两个不同的firebase集合

dependencies:
  cloud_firestore: ^2.5.4

import 'package:cloud_firestore/cloud_firestore.dart';

FirebaseFirestore firestore = FirebaseFirestore.instance;

CollectionReference collection1 = firestore.collection('collection1');
CollectionReference collection2 = firestore.collection('collection2');

Future<void> getData() async {
  QuerySnapshot snapshot1 = await collection1.get();
  QuerySnapshot snapshot2 = await collection2.get();

  // 处理数据
}

for (QueryDocumentSnapshot document in snapshot1.docs) {
  // 处理collection1中的文档数据
}

for (QueryDocumentSnapshot document in snapshot2.docs) {
  // 处理collection2中的文档数据
}