firestore firebase 问题：如何在不指定文档名称的情况下更新文档

Question

I want to access UserPrefs and access the weather_location directly without specifying the document name. How can I do that?

const res = await firestore().collection('Users').doc(uid).collection('userPrefs').doc().set({weather_location: location});

Answer 1

You can query the collection UserPrefs and find all the documents that contain a field "weather_location", then update all of them or only one.

something like:

const querySnapshot = await firestore()
    .collection('Users')
    .doc(uid)
    .collection('userPrefs')
    .where('weather_location', '>', '')
    .get();

const firstDoc = querySnapshot.docs[0];

await firestore()
    .collection('Users')
    .doc(uid)
    .collection('userPrefs')
    .doc(firstDoc.id)
    .set({weather_location: location});