Ordering & Limiting

orderBy

orderBy takes a function that returns a Dart record of field selectors. Each selector sorts ascending unless you pass descending: true.

// Most followers first, then by name A-Z
final sorted = await odm.users
    .orderBy(($) => (
          $.profile.followers(descending: true),
          $.name(),
        ))
    .get();

A record with one field needs a trailing comma:

final byAge = await odm.users.orderBy(($) => ($.age(),)).get();

The record's type is the query's cursor type; see Pagination. You can add $.documentId() as a last term to break ties between documents with equal values.

Firestore rules still apply. For example, a query with a range filter (isLessThan, isGreaterThan, and so on) on a field must order by that field first, and some combinations need a composite index.

final adults = await odm.users
    .where(($) => $.age(isGreaterThanOrEqualTo: 18))
    .orderBy(($) => ($.age(), $.name()))
    .get();

limit and limitToLast

• limit(n) returns the first n results.
• limitToLast(n) returns the last n results, still in orderBy order. It requires orderBy.

final top10 = await odm.users
    .orderBy(($) => ($.profile.followers(descending: true),))
    .limit(10)
    .get();

final newest3 = await odm.users
    .orderBy(($) => ($.createdAt(),))
    .limitToLast(3)
    .get();