为什么 gremlin-server 没有通过它的 ID 返回一条边？

Question

I'm using gremlin-server 3.4.11 and connecting to it with java tinkerpop gremlin-driver.

gE() returns all the edges:

[
  {
    "id": 18,
    "label": "RELATED",
    "type": "edge",
    "inVLabel": "GREMLIN2",
    "outVLabel": "GREMLIN1",
    "inV": 16,
    "outV": 14
  }
]

but gE(18) OR gE().hasId(18) returns empty list:

[]

Why is that? I would assume, that the corresponding edge would be returned, but it is not. What am I missing here?

Note : I tried to create an edge with gV(14).addE('RELATED').property('id', 'someId').to(gV(16)) .. this is then found with gE().has('id', 'someId') , BUT it is not the ID of the edge, merely property named 'id'. hasId() step also returns empty list.

Any hints would be greatly appreciated!

Answer 1

Are you using TinkerGraph? Is yes, the IDs are stored as long internally.

Please try gE(18L)

Answer 2

There are a number of different Graphs; If you are using Tinker Graph then you have to use: the format L. This is because the ID value is stored as a long internally for the tinkerPop Graph. Some use case examples are: gV(1L) this will return a vertex with an ID of 1. Likewise, the ID's for edges are stored as longs too; gE(2L) returns the edge with an ID of 2