orderBy property

The order to apply to the query results.

Firestore allows callers to provide a full ordering, a partial ordering, or no ordering at all. In all cases, Firestore guarantees a stable ordering through the following rules:

• The order_by is required to reference all fields used with an inequality filter.
• All fields that are required to be in the order_by but are not already present are appended in lexicographical ordering of the field name.
• If an order on __name__ is not specified, it is appended by default.

Fields are appended with the same sort direction as the last order specified, or 'ASCENDING' if no order was specified. For example:

• ORDER BY a becomes ORDER BY a ASC, __name__ ASC
• ORDER BY a DESC becomes ORDER BY a DESC, __name__ DESC
• WHERE a > 1 becomes WHERE a > 1 ORDER BY a ASC, __name__ ASC
• WHERE __name__ > ... AND a > 1 becomes WHERE __name__ > ... AND a > 1 ORDER BY a ASC, __name__ ASC