从子集合firestore + FLUTTER中检索信息

import 'package:cloud_firestore/cloud_firestore.dart';

// 获取Firestore实例
final FirebaseFirestore firestore = FirebaseFirestore.instance;

// 检索子集合中的信息
Future<void> retrieveDataFromSubcollection() async {
  try {
    // 获取子集合的引用
    CollectionReference subcollectionRef = firestore
        .collection('parent_collection')
        .doc('parent_document')
        .collection('subcollection');

    // 查询子集合中的文档
    QuerySnapshot querySnapshot = await subcollectionRef.get();

    // 遍历查询结果
    querySnapshot.docs.forEach((doc) {
      // 获取文档数据
      Map<String, dynamic> data = doc.data();
      // 处理数据...
    });
  } catch (e) {
    // 处理错误
    print('Error retrieving data from subcollection: $e');
  }
}

// 调用函数来检索信息
retrieveDataFromSubcollection();