Have an empty docs in querySnaphsot when trying to get data with firebase-CodePudding

I recently developped a firebase schedule function to retrieve data on every monday. I tested it during the previous days and it was working correctly. However, this morning, I discovered that my query wasn't able anymore to retrieve data as it used to do. I now have an empty array at QuerySnapshot.docs. You can find my code below:

const functions = require("firebase-functions");
const admin = require("firebase-admin");
admin.initializeApp();
const db = admin.firestore();

exports.scheduledFunction = functions.pubsub.schedule("0 0 * * 1").onRun(async () => {
  console.log("start");
  const querySnapshotnext = await db.collection("Next_challenges").orderBy("createdAt").get();

  console.log("Let see querySnapshot :", querySnapshotnext); //it works, I can see QuerySnapshot object
  console.log("Let see docs :", querySnapshotnext.docs); //have an empty array [] even if it should not, it wasn't empty few days ago
  console.log("let see the data of the first doc : ", querySnapshotnext.docs[0].data()); //is of course undefined
  
  return null;
});

You can find my database below with the doc that is normally selected:

The rules of my databases are the following :

I don't really understand why my code isn't working anymore, I think it's certainly related to some parameters stuffs and don't really know how I could debug this by myself so don't hesitate to give me some tips so I can be more autonomous with firebase. Thank you :)

CodePudding user response：

Firestore's documentation has a note that says,

An orderBy() clause also filters for existence of the given field. The result set will not include documents that do not contain the given field.

You have .orderBy("createdAt") in your query but there isn't any createdAt field in the documents (at least the one in screenshot). Did you change your document structure recently that is causing this issue?

Also the Admin SDK bypasses any security rules so I'd recommend setting them to false if you don't need to access data directly from client.