Edge additions not supported

[Damien Seguy]

I'm moving from Gremlin 3.3.7 to 3.4.2, and I'm running into this weird error message : "Edge additions not supported"

The origin is this script : The problem arise by using addEdge(). 

toVertex and fromVertex are both vertices. 

getIt = { id ->
  def p = g.V(id);
  p.next();
}


new File('/path/to/file').eachLine {
    (fromVertex, toVertex) = it.split(',').collect(getIt);
    fromVertex.addEdge('DEFINITION', toVertex);
}

I tried to move to the addE syntax with this : 

    g.addE('DEFINITION34').from(fromVertex).to(toVertex)

This has the weirder effect to load only the LAST element from the file. All others are omitted.

the file only  contains IDs, and are valid with Gremlin 3.3.7.

I also use the neo4j plugin, and I'm running on OSX. 

What am I doing wrong ? 

Damien Seguy.

[Stephen Mallette]

That error message occurs when you try to call addEdge() on a "detached" vertex, so I assume that your fromVertex and toVertex are both of the DetachedVertex or ReferenceVertex classes. This approach should have failed in 3.3.x as well, so I'm not sure what else changed. Ultimately you should be making the change (on 3.3.7 or otherwise) to the g.addE() syntax. I would simply prefer (untested, but i think i got it right):

new File('/path/to/file').eachLine {
    (fromVertex, toVertex) = it.split(',')

    g.V(fromVertex).addE('DEFINITION34').to(V(toVertex)).iterate()
}

And, of course note, that it doesn't matter what version of TinkerPop you're using from 0.x to 3.x, you need to iterate() your traversal:

http://tinkerpop.apache.org/docs/current/tutorials/the-gremlin-console/#result-iteration  

it's curious that you mention neo4j...are you using that as your database? it doesn't allow id assignment, so that may be a problem for you as well.

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[Damien Seguy]

On Tuesday, June 25, 2019 at 9:25:13 PM UTC+2, Stephen Mallette wrote:

That error message occurs when you try to call addEdge() on a "detached" vertex, so I assume that your fromVertex and toVertex are both of the DetachedVertex or ReferenceVertex classes. This approach should have failed in 3.3.x as well, so I'm not sure what else changed. Ultimately you should be making the change (on 3.3.7 or otherwise) to the g.addE() syntax. I would simply prefer (untested, but i think i got it right):

new File('/path/to/file').eachLine {
    (fromVertex, toVertex) = it.split(',')
    g.V(fromVertex).addE('DEFINITION34').to(V(toVertex)).iterate()
}

Perfectly understood, and it works on the first try. Efficient as usuall, Stephen!

 

And, of course note, that it doesn't matter what version of TinkerPop you're using from 0.x to 3.x, you need to iterate() your traversal:

I have been biten by this one more than once, but it didn't occur to me that it was needed there, since this expression only process one link at a time. 

I wish I could process the file in batch, and I'll probably test a suggestion in a previous thread, about grouping the links by one of the ends. 

 

http://tinkerpop.apache.org/docs/current/tutorials/the-gremlin-console/#result-iteration  

it's curious that you mention neo4j...are you using that as your database? it doesn't allow id assignment, so that may be a problem for you as well.

I mentioned it as part of the used architecture, which is standard when I submit such a question. 

id assignement is not an issue here : I run a lot of small graph, and destroy them once finished.

In case of any problem, I can always rebuild them. I found a way to synch the ids for my purpose, using neo4j or thinkergraph. 

Best regards,

Damien Seguy.

 

On Tue, Jun 25, 2019 at 12:08 PM Damien Seguy <damie...@gmail.com> wrote:

I'm moving from Gremlin 3.3.7 to 3.4.2, and I'm running into this weird error message : "Edge additions not supported"

The origin is this script : The problem arise by using addEdge(). 

toVertex and fromVertex are both vertices. 

getIt = { id ->
  def p = g.V(id);
  p.next();
}


new File('/path/to/file').eachLine {
    (fromVertex, toVertex) = it.split(',').collect(getIt);
    fromVertex.addEdge('DEFINITION', toVertex);
}

I tried to move to the addE syntax with this : 

    g.addE('DEFINITION34').from(fromVertex).to(toVertex)

This has the weirder effect to load only the LAST element from the file. All others are omitted.

the file only  contains IDs, and are valid with Gremlin 3.3.7.

I also use the neo4j plugin, and I'm running on OSX. 

What am I doing wrong ? 

Damien Seguy.

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