Navigations

Navigation properties may be used to easily construct queries that span entity relationships, avoiding the need to manually join entities based on foreign keys relationships. This a powerful feature that allows you to work with your data in a more natural way.

For example, we can query artists that have at least one album.

const navigation = await db.from.artists
  .where(a => a.albums.length > 1)
  .toArray();

In this example, the albums property is a navigation property that allows us to query albums related to an artist, Verse understands the length property and generates the appropriate SQL query.

select "t1"."ArtistId", "t1"."Name"
from "Artist" as "t1"
where (
   select count(*)
   from "Album" as "t2"
   where "t1"."ArtistId" = "t2"."ArtistId"
) > 1

What if we want to query the names of any artists that have a track called "Today"?

const navigation2 = await db.from.tracks
  .where(t => t.name === "Today")
  .select(t => t.album.artist.name)
  .toArray();

Navigations work anywhere you have a reference to an entity, so you can even do things like this:

const navigation3 = await db.from.albums
  .select(a => ({ foo: { bar: a }, baz: a }))
  .where(o => o.foo.bar.artist.name === "Alice In Chains")
  .toArray();

Here, even though we are putting each album into the foo.bar property of an intermediate object, we are still able to navigate to the related artist and filter on their name.