Cosmos DB Gremlin“项目”未产生预期结果

Question

I have the following traversal that shows that the selected Vertex has 14 Edges labeled "follows".

 g.V().has('user','email','me@email.com').project('name','email','follow-edges').by('name').by('email').by(outE().hasLabel('follows').project('id','inV').by('id').by('inV'))

Which produces the following results:

[{
"name": "David",
"email": "me@email.com",
"follow-edges": 14}]

But when I want to project the "follows" Edge's id and inV ids, I'm only getting one result item back.

g.V().has('user','email','david@me.com').project('name','email','follow-edges').by('name').by('email').by(outE().hasLabel('follows').project('edge-id', 'inV-id').by('id').by('inV'))

Results:

[{
"name": "David",
"email": "me@email.com",
"follow-edges": {
  "edge-id": "ccc06183-f4ca-410d-9c3c-9d2dfd93f5f0",
  "inV-id": "f4703a07-f42d-46f9-86be-7f5440f07f12"
}}]

I was expecting to get a list of all the "follows" edge's for the selected vertex. Similiar to the answer given by Stephen Mallette at this link .

Does anyone know why this is not working?

Answer 1

You need to reduce the stream of objects in your anonymous traversal in by() - note my addition of fold() :

g.V().has('user','email','david@me.com').
  project('name','email','followedges').
    by('name').
    by('email').
    by(outE().hasLabel('follows').
       project('edge-id', 'inV-id').
         by('id').
         by('inV').fold())

I assume that "inV" is an actual property and you're not trying to get the "in vertex" of the edge. If you are trying to get the "in vertex" then you need by(inV().id()) .