Pagination Using StartAt() When Ordering By Child

I am trying to just retrieve a list of records, sorted by one of the fields in each record, and I would like to be able to retrieve the data in pages. According to the Firebase doc

Solution 1:

You're almost there!

The problem is in how you call startAt for the second page:

.startAt(null, '-KlstB51ap1L2tcK8cL6')

To get the correct results you need to pass in both the price and the key of the so-called anchor item:

.startAt(99, '-KlstB51ap1L2tcK8cL6')

With that Firebase will find all items with price 99 and then return items starting at key '-KlstB51ap1L2tcK8cL6'.