Edges

Edges are used in graphs to link vertices together. They are documents with two additional system attributes that you set, a _from and a _to attribute. They need to be stored in edge collections.

Together with vertex documents stored in document collections (also called vertex collections in this context), edges form graphs.

Example

• An edge collection stores the information that a company’s reception is a sub-unit to the services unit and the services unit is sub-unit to the CEO. You would express this relationship with the _from and _to attributes.
• A vertex collection stores all the properties about the reception, for example, that 20 people are working there, the room number, and so on.
• The _from attribute of an edge is the document ID of the linked vertex (incoming relation).
• The _to attribute of an edge is the document ID of the linked vertex (outgoing relation).

Edges API

Edges are normal documents but additionally have a _from and a _to attribute that you need to set. You can update the _from and _to attributes like any other document attribute using the Documents API.

For methods you can call on edge collections, see the edge document methods of the collection object.