Firestore: orderBy in desc order returns empty array if combined with startAfter

[Hamza-Khurshid]

Issue

I am trying to query a list of users in firestore that should be sorted in descending order by number of "votes" property and using startAfter to paginate the results.
But it returns empty array always. It returns results if I change orderBy to asc. I have followed documentation but still facing this unexpected behavior.

db.collection("users") .orderBy(votes', 'desc') .startAfter(page*5) .limit(5) .get()

Project Files

Dependencies

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package.json:

"dependencies": {
"@react-native-firebase/app": "^10.0.0",
"@react-native-firebase/auth": "^10.0.0",
"@react-native-firebase/firestore": "^10.0.0",
"@react-native-firebase/storage": "^10.0.0",
"@react-navigation/bottom-tabs": "^5.8.0",
"@react-navigation/native": "^5.7.3",
"@react-navigation/stack": "^5.9.0",
"axios": "^0.21.0",
"firebase": "^7.21.0",
"native-base": "^2.13.14",
"prop-types": "^15.7.2",
"react": "16.13.1",
"react-native": "0.63.2",

# N/A

[mikehardy]

This should be an issue, not a discussion. Please open a new issue following the template
Prior to doing that though, please make sure this works in general (perhaps by doing a quick test with firebase-js-sdk or by checking how we validate it in our test suite - do we exercise this functionality? If not and you add a test does it fail? https://github.com/invertase/react-native-firebase/tree/master/packages/firestore/e2e/Query )

[Hamza-Khurshid]

Hey Mike It was my mistake I just stepped on the solution. I thought startAfter receives the starting index of query but it was actually field value. `db.collection("users") .orderBy(votes', 'desc') .startAfter(page*5) .limit(5) .get()` here I was keeping page numbers and then multiplying with 5 to get next five results. But now I give the number of votes of last user in startAfter so that next users can be fetched: `db.collection("users") .orderBy(votes', 'desc') .startAfter(1020) .limit(5) .get()`

…

On Tue, Nov 24, 2020 at 12:07 AM Mike Hardy ***@***.***> wrote: This should be an issue, not a discussion. Please open a new issue following the template Prior to doing that though, please make sure this works in general (perhaps by doing a quick test with firebase-js-sdk or by checking how we validate it in our test suite - do we exercise this functionality? If not and you add a test does it fail? https://github.com/invertase/react-native-firebase/tree/master/packages/firestore/e2e/Query ) — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#4601 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ALKNU7V5L5EEAJJBDGIBVX3SRKXG5ANCNFSM4T7Z2KDQ> .