Using ArcadeEdge type with query.

[marr]

Hi, I am trying to leverage the ArcadeEdge type when using query(). I have a type like this:

type Thing = ArcadeVertex<Equipment & {
  site: ArcadeEdge<Site>
}>;

In the actual db schema, there is an Equipment vertex type that contains a has_equipment incoming edge. I try to do the following:

const result = await db.query<Thing>(
  'sql',
  'SELECT DISTINCT location, in(\'has_equipment\') as site from Equipment LIMIT 10'
);

and I do get back results like:

[{ location: null, site: [{ name: ... }] }]

which is nice, but the type hinting in the IDE is not correct. It shows site as a single object, when the result is actually an array.
I know this is sort of documented, but maybe you could help me understand the best approach to query on edges like that?

[apttap]

Your type as defined expects a single edge:

ArcadeEdge<Site> // contains a single edge

the in() operator returns all incoming vertices.
Stated another way: it starts at the vertex targeted in the query, then follows each incoming edge to collect the connected vertices.

The type of site in Thing should be:

ArcadeVertex<Site>[] // a list of all vertices with in-edges to the target vertex

(You also might want to look at: inE(), which returns all incoming Edges for the Vertex targeted in the query.)

Also consider your query does not return ArcadeVertex[] at the top level:
When you query SELECT * FROM Equipment, you’d get vertices.

When you SELECT property, in(), you’re no longer returning just vertices, you’re creating a different object shape:

{ 
  location: null, // primitive?
  site: [{ name: ... }] // a list of incoming vertices
}

The expected return type could be:

type Thing = {
  location: unknown;
  site: ArcadeVertex<Site>[];
};

The type parameter on the query() method is just the expected return type, not necessarily a vertex or an edge. The type documentation for Sprite is sort of rough right now, but:

ArcadeVertex<T> compiles to something like:

type ArcadeVertex<T extends object> = {
  /** The id of the record. */
  '@rid': string;
  /** The category of the record. */
  '@cat': 'v';
  /** The type of the record. */
  '@type': string;
} & T;

That would extend the type provided as a parameter with the ArcadeDB record meta, but I don't think that is a part of your returned object. Sprite was "designed" this way to serve as a lower-level library to build other tools like an OGM/ORM. You could build your own getVertex<T>() method (for example) from a query<ArcadeVertex<T>>() call, without any unnecessary abstraction to get in the way.

If you do not want an array, say there's only one Vertex, I think perhaps wrapping the in() operator in first() like first(in('has_equipment')) might work for you, but I honestly can't tell you the best way to do it. I recommend the official discord. Luca, the author of ArcadeDB (and OrientDB), is always there and answers quickly (if the user group doesn't answer first). If you really want the definitive answer on ArcadeDB related questions I would speak to him, though I am happy to talk about it too.