在Firebase函数中查询嵌套文档

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();

const firestore = admin.firestore();

exports.getNestedDocument = functions.https.onRequest(async (req, res) => {
  try {
    const parentDocId = req.query.parentDocId;
    const nestedDocId = req.query.nestedDocId;

    const parentDocRef = firestore.collection('parentCollection').doc(parentDocId);
    const nestedDocRef = parentDocRef.collection('nestedCollection').doc(nestedDocId);

    const nestedDocSnapshot = await nestedDocRef.get();

    if (nestedDocSnapshot.exists) {
      const nestedDocData = nestedDocSnapshot.data();
      res.status(200).json(nestedDocData);
    } else {
      res.status(404).send('Nested document not found');
    }
  } catch (error) {
    console.error(error);
    res.status(500).send('Error retrieving nested document');
  }
});