I saw the Firestore documentation and I need exactly a feature, that is not possible. I want to filter comments from a specific user and want to order his comments by date.

Like below (which is invalid according to Firestore):

docRef
    .whereField("user", isEqualTo: "John Doe")
    .order(by: "date")

How could I achieve this?

CodePudding user response：

You have to create an Index before you sort by another field than filtered. Go to Cloud Firestore -> Indexes to create it or follow the link provided in the error log.

CodePudding user response：

Firestore order and filter in multiple fields within these limitations. The combination you're showing in your code does not hit those limitations as far as I can see, so it should be possible. Most likely you're just missing the necessary index.

If you want to filter/order on multiple fields, you'll need to define an index on that combination of fields. When the necessary index is missing, the output of your app will contain a message to that effect, which contains a direct link that you can click to create the index with all necessary fields prepopulated. So check the log output of your app for such a message whenever you're not getting the results you expect.