CODEWITHSUNDEEP
azure-cosmosdbgremlinazure-cosmosdb-gremlinapi
Cristian Diaconescu
Cristian Diaconescu

Reputation: 35641

CosmosDB Gremlin - filter nodes that don't have a particular type of edge

In a CosmosDB Graph collection, I'm trying to find all nodes of type typeA that do not have any "live" edges pointing to nodes of type typeB.

Some edges may be "soft-deleted" (i.e. g.E().has('softDeleted', true) ). These edges should be ignored.

This is what I tried:

g.V().hasLabel('typeA')
-> returns 10 nodes of type "typeA", as expected

g.V().hasLabel('typeA')
     .outE().not(has('softDelete', true))
     .inV().hasLabel('typeB')
-> returns 2 nodes of type "typeB", as expected

g.V().hasLabel('typeA')
     .where( // same condition as above, inside a 'where' clause
         outE().not(has('softDelete', true))
         .inV().hasLabel('typeB')
         .count().is(eq(0))   // " where there are no such edges"
     )
-> returns all 10 nodes of type "typeA" again ?!

In the query above, applying the where clause seems to not filter anything.

Upvotes: 0

Views: 393

Answers (1)

Daniel Kuppitz
Daniel Kuppitz

Reputation: 10904

The following query will find all typeA vertices that do not have an edge to a typeB vertex. Only edges that have no softDelete property or that edges that have softDelete set to false will be considered, other edges will be ignored.

g.V().hasLabel('typeA').
  not(outE().or(hasNot('softDelete'),
                has   ('softDelete', false)).
        inV().hasLabel('typeB'))

Upvotes: 1

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