How to use multiple hashmaps in gremlin to generate dynamic properties when adding vertices

Question

I want to create PARENT - HAS_CHILD -> CHILD nodes in my graph database using single gremlin traversal.

Problem is that PARENT vertex, HAS_CHILD edge and CHILD vertex have different properties and should come from different Hashmaps.

I am using java api for gremlin.

I have not found any way of doing it and would appreciate help on this.

Update:::

I was able to achieve using multiple maps like this:

Map<String, String> map1 = new HashMap<String, String>(); map1.put("a", "1"); map1.put("b", "2"); map1.put("c", "3");

Map<String, String> map2 = new HashMap<String, String>(); map2.put("aa", "11"); map2.put("bb", "22"); map2.put("cc", "33");

g.withSideEffect("map1", map1).withSideEffect("map2", map2) .addV(label).as("vertex1").sideEffect(__.select("map1").unfold().as("kv").select("vertex1").property(__.select("kv").by(Column.keys),
__.select("kv").by(Column.values))) .addV(label).as("vertex2").sideEffect(__.select("map2").unfold().as("kv").select("vertex2").property(__.select("kv").by(Column.keys),__.select("kv").by(Column.values))) .iterate();

Thanks for the help.

score 0 · Accepted Answer · answered Apr 28 '20 at 11:58

The answer to this problem is pretty similar to other questions on using a Map of properties to dynamically construct vertices and edges. That patterns are largely the same and derive from using unfold() to deconstruct a Map of properties to a stream of pairs and then calling property(k,v) for each. The approach is described in some detail in this blog post. While that post describes the loading of a single vertex, the ability to adapt that example to what you're looking for comes from understanding basic collection manipulation functions of Gremlin.

gremlin> pair = [[name:'marko',age:29,country:'usa'],[name:'stephen',age:33,country:'usa']]
==>[name:marko,age:29,country:usa]
==>[name:stephen,age:33,country:usa]
gremlin> g.withSideEffect('pair',pair).
......1>   addV('person').as('o').
......2>   sideEffect(select('pair').limit(local,1).
......3>              unfold().as('kvo').
......4>              select('o').
......5>              property(select('kvo').by(Column.keys), select('kvo').by(Column.values))).
......6>   addV('person').as('i').
......7>   sideEffect(select('pair').tail(local).
......8>              unfold().as('kvi').
......9>              select('i').
.....10>              property(select('kvi').by(Column.keys), select('kvi').by(Column.values))).
.....11>   addE('knows').
.....12>     from('o').to('i').iterate()
gremlin> g.V().elementMap()
==>[id:0,label:person,country:usa,name:marko,age:29]
==>[id:4,label:person,country:usa,name:stephen,age:33]
gremlin> g.E()
==>e[8][0-knows->4]

Hi Stephen, I went through the blog post. It is helpful and gives an example of using 'lists of maps' containing properties but the property types are all the same. In my case, the property types are different for parent, relation and child. Is there a way for me to inject 3 different types of maps? — Umar Farman Ali, Apr 30 '20 at 05:10

How to use multiple hashmaps in gremlin to generate dynamic properties when adding vertices

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