2

This is my test data:

graph = TinkerGraph.open()
g= graph.traversal()
g.addV('Account').property('id',"0x0").as('a1').
  addV('Account').property('id',"0x1").as('a2').
  addV('Account').property('id',"0x2").as('a3').
  addV('Token').property('address','1').as('tk1').
  addV('Token').property('address','2').as('tk2').
  addV('Token').property('address','3').as('tk3').
  addV('Trx').property('address','1').as('Trx1').
  addV('Trx').property('address','1').as('Trx2').
  addV('Trx').property('address','3').as('Trx3').
  addE('sent').from('a1').to('Trx1').
  addE('sent').from('a2').to('Trx2').
  addE('received_by').from('Trx1').to('a2').
  addE('received_by').from('Trx2').to('a3').
  addE('distributes').from('a1').to('tk1').
  addE('distributes').from('a1').to('tk2').
  addE('distributes').from('a1').to('tk3').
  iterate()

I need to first get all the Token addresses using the distributes relationship and then with those values loop through a traversal. This is an example of what I need for one single token

h = g.V().has('Account','id','0x0').next()
token = '1'
g.V(h).
      out('sent').has('address',token).as('t1').
      out('received_by').as('a2').
      out('sent').has('address',token).as('t2').
      out('received_by').as('a3').
      select('a3','a2'). \
         by('id').toList()

This is the output:

[a3:0x2,a2:0x1]

Instead of doing that has('address',token) on each hop I could omit it and just make sure the token address is the same by placing a where('t1',eq('t2')).by('address') at the end of the traversal, but this performs badly given my database design and indexes.

So what I do to iterate is:

tokens = g.V(h).out('distributes').values('address').toList()
finalList = []
for (token in tokens){    
    finalList.add(g.V(h).
      out('sent').has('address',token).
      out('received_by').as('a2').
      out('sent').has('address',token).
      out('received_by').as('a3').
      select('a3','a2'). \
         by('id').toList())  
 }

And this is what's stored in finalList at the end:

==>[[a3:0x2,a2:0x1]]
==>[]
==>[]

This works but I was wondering how can I iterate that token list this way without leaving Gremlin and without introducing that for loop. Also, my results contain empty results which is not optimal. The key here for me is to always be able to do that has('address',token) for each hop with the tokens that the Account node has ever sent. Thank you very much.

andres_est83
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  • Could you please provide a Gremlin script that creates some sample data - here is an example https://stackoverflow.com/questions/51388315/gremlin-choose-one-item-at-random – stephen mallette Aug 05 '20 at 14:41
  • @stephenmallette I added my test data and edited the whole explanation to make it clearer. Thank you. – andres_est83 Aug 08 '20 at 13:17

1 Answers1

0

There is still uncertainty about what you are trying to achieve.

Nevertheless, I think this query does what you need:

g.V().has('Account', 'id', '0x0').as('a').
  out('distributes').values('address').as('t').
    select('a').
  repeat(out('sent').where(values('address').
        as('t')).
    out('received_by')).
  emit()

Example: https://gremlify.com/spwya4itlvd

Kfir Dadosh
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