need to join the vertex in dse - datastax

Question

I have created properties and vertex like
schema.propertyKey('REFERENCE_ID').Int().multiple().create();
schema.propertyKey('Name').Text().single().create();
schema.propertyKey('PARENT_NAME').Text().single().create(); ... ....
.. schema.propertyKey('XXX').Text().single().create();
schema.vertexLabel('VERT1').properties("REFERENCE_ID",.."PROPERTY10"....."PROPERTY15")//15
PROPERTIES
schema.vertexLabel('VER2').properties("REFERENCE_ID",.."PROPERTY20"......"PROPERTY35")//35
PROPERTIES
schema.vertexLabel('VERT3').properties("REFERENCE_ID",.."PROPERTY20"....."PROPERTY25")//25
PROPERTIES
schema.vertexLabel('VERT4').properties("REFERENCE_ID",.."PROPERTY20"....."PROPERTY25")//25
PROPERTIES
and loaded csv data using DSG GRAPHLOADER(CSV TO(VERTEX)).
and created edge
schema.edgeLabel('ed1').single().create()
schema.edgeLabel('ed1').connection('VERT1', 'VER2').add()
schema.edgeLabel('ed1').single().create()
schema.edgeLabel('ed1').connection('VERT1', 'VERT3').add()
schema.edgeLabel('ed2').single().create()
schema.edgeLabel('ed2').connection('VERT3','VERT4').add()
But I don't know how to map the data between vertex and edge. I want to join all these 4 vertex. Could you please help on this?
I'm new to dse. I just ran the above code in datastax studio successfully and I can see the loaded data. I need to join the vertex...
Sql code: I want same in dse germlin.
select v1.REFERENCE_ID,v2.name,v3.total from VERT1 v1
join VER2 v2 on v1.REFERENCE_ID=v2.REFERENCE_ID
join VERT3 v3 on v2.sid=v3.sid

Answer 1

there are 2 "main" options in DSE for adding edge data, plus one if you're also using DSE Analytics.
One is to use Gremlin, like what's documented here - https://docs.datastax.com/en/dse/6.0/dse-dev/datastax_enterprise/graph/using/insertTraversalAPI.html
This approach would be a traversal based approach and may not be the best/fastest choice for bulk operations
Another solution is to use the Graph Loader, check out the example with the .asEdge code sample here - https://docs.datastax.com/en/dse/6.0/dse-dev/datastax_enterprise/graph/dgl/dglCSV.html#dglCSV
If you have DSE Analytics enabled, you can also use DataStax's DSE GraphFrame implementation, which leverages Spark, to preform this task as well. Here's an example - https://docs.datastax.com/en/dse/6.0/dse-dev/datastax_enterprise/graph/graphAnalytics/dseGraphFrameImport.html