Gremlin Script to select multiple vertices with labels from the previous statements

[Venkata Phani Kumar Mangipudi]

I want to do the following from gremlin script, 

> m = g.V().addV(label,'Person','name','Marko').iterator().next(); d = g.V().addV(label, 'Person','name', 'Daniel').iterator().next(); pl = g.addV(label,'Place','place_name','California').iterator().next(); m.addEdge('livesIn', pl); m.addEdge('friend', d);

With the above script, I am able to create persons Marko, Daniel, and place "California" and create edges between Marko and California AND Marko and Daniel.

I want to retrieve the vertex Ids created by the system for subsequent processing in my application. Hence, I want to extend the above script and retrieve the vertices I just created at the end of the script with some labels associated to them. say, I want the result something like: 

==>marko=v[8232]
==>daniel=v[8252]
==>place=v[4136]

When I add "inject(m, d, pl)" at the end of above script, I am getting the vertices, but not able to assign them some labels.

I tried, union, group, and steps in multiple ways but was not able to come up with the solution. Kindly help.

[Mark Henderson]

Would doing at the end of your script help?

['marco':m,'daniel':d,'place':the_variable_your_edge_is_assigne_to];

[Daniel Kuppitz]

You can make that a single statement:

gremlin> g = TinkerGraph.open().traversal()
==>graphtraversalsource[tinkergraph[vertices:0 edges:0], standard]
gremlin> g.addV(label, 'Person', 'name', 'Marko').as('marko').
gremlin>   addV(label, 'Person', 'name', 'Daniel').as('daniel').
gremlin>   addV(label, 'Place',  'name', 'California').as('place').
gremlin>   addE('livesIn').from('marko').to('place').
gremlin>   addE('friend').from('marko').to('daniel').select('marko', 'daniel', 'place')
==>[marko:v[0], daniel:v[2], place:v[4]]

However, this graph is based on wrong assumptions. Neither does Marko live in California, nor are Marko and Daniel friends ;).

Cheers,

Daniel

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[Venkata Phani Kumar Mangipudi]

Thank you Mark, tried this and it worked great :)

[Venkata Phani Kumar Mangipudi]

Thank you very much Daniel for the insights and also the domain knowledge :) 

Next time, I'll be careful with my examples and will stick to the domain as close as possible and avoid assumptions ;)

The aliases we create are pertaining to only one statement, right. 

Do I have any additional benefit (say performance) with single statement vs multiple statements?

Thanks and Best Regards,

Phani

[Daniel Kuppitz]

Yes, a single statement will be (marginally) faster, since there's only one traversal that needs to be compiled (when I say "compiled" I mean the process where traversal strategies get applied).

Cheers,

Daniel

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[Venkata Phani Kumar Mangipudi]

Thank you very much Daniel. 

I'll use single statement for better performance, where ever I can do with good readability. 

Thanks and Best Regards,

Phani