Does't neo4j support node-set?

[flyly0755]

Usually parents-child relationship with 3 nodes(father, mather, child):
fatherX---father-child_relation--->childX,
MatherX---mather-child_relation--->childX,
FatherX---huaband-wife_relation--->MatherX,

Is there super node-set conception or similar function which can combine sub-nodes?
For example: super node-set ParentX with sub-nodes fatherX and matherX, so only need just one relation with child like:
ParentX---parent-child_relation--->ChildX

And even create super node-set familiyX with sub-nodes fatherX, and matherX, ChildX and so on.

[LinneaAndersson]

Hi @flyly0755! In neo4j a relationship must be connected to exactly 2 nodes. However, you can have multiple labels which makes it easy to "group" nodes. Let's say you want to create a mother and a father which are parent of a child. You could create two relationships like this:

CREATE (mother:Mother:Parent)-[:PARENT_OF]->(child:Child{name:"kalle"})
CREATE (father:Father:Parent)-[:PARENT_OF]->(child)

if you then would like to find both parents, you could do that with the query:

MATCH (parent:Parent)-[:PARENT_OF]-(:Child{name:"kalle"}) RETURN parent

So, you can't have more than two nodes per relationship - but you can use multiple labels for your nodes and pattern matching to find all relationships to a given node. Does this help you? Please let me know if I have misunderstood your question/feature request.

[flyly0755]

@LinneaAndersson yes, a node can with multiple labels, which can be very useful.
relationship must be connected to exactly 2 nodes. -- This is a basic prerequisite.
What i think about is whether we can consider node-set concept, which can bring lots of convenience to indicate physical world include-relationship instead of point to point relationship, for example:
FamilyA contains fatherA, matherA, childA, and FamilyB contain fatherB, matherB, childB.
Assume FamilyA is a node with 3 sub-nodes(fatherA, matherA, childA),
FamilyB is a node with 3 sub-nodes(fatherB, matherB, childB), So family and member are include-relationship.
and FamilyA, FamilyB are good neighbor which is point to point relationship.

This is related with geometry(point, edge and so on), maybe what i think above is not feasible with geometry foundation:)

[LinneaAndersson]

@flyly0755 Ok, now I think I understand your question/feature-request 👍

I will add it as a feature request. The only thing I can come up with that you could do today, is that you could create a node which is the node-set (in this case it would then be to create family nodes):

Or in cypher:

CREATE (familyA:Family{name:"familyA"}),
       (familyA)-[:HAS_FAMILY_MEMBER]->(childa:Child{name:"childA"}), 
       (familyA)-[:HAS_FAMILY_MEMBER]->(mothera:Mother{name:"motherA"}),
       (familyA)-[:HAS_FAMILY_MEMBER]->(fathera:Father{name:"fatherA"}),
       (fathera)-[:PARENT_TO]->(childa),
       (mothera)-[:PARENT_TO]->(childa)
CREATE (familyB:Family{name:"familyB"}),
       (familyB)-[:HAS_FAMILY_MEMBER]->(childb:Child{name:"childB"}), 
       (familyB)-[:HAS_FAMILY_MEMBER]->(motherb:Mother{name:"motherB"}),
       (familyB)-[:HAS_FAMILY_MEMBER]->(fatherb:Father{name:"fatherB"}),
       (fatherb)-[:PARENT_TO]->(childb),
       (motherb)-[:PARENT_TO]->(childb)
CREATE (familyA)-[:IS_NEIGHBOUR_TO]->(familyB), 
       (familyB)-[:IS_NEIGHBOUR_TO]->(familyA)

[LinneaAndersson]

Thanks for the feature request. I will close this issue now and we will let you know when we have more information. Please let me know if there is anything else we can help you with.

[LinneaAndersson]

@flyly0755 does the suggested model work for your use-case? (that is: to create a node which represents the node-set) Is there something a node-set can provide than a node representing a node-set can not?

[flyly0755]

@flyly0755 Ok, now I think I understand your question/feature-request 👍

I will add it as a feature request. The only thing I can come up with that you could do today, is that you could create a node which is the node-set (in this case it would then be to create family nodes):

Or in cypher:

CREATE (familyA:Family{name:"familyA"}),
       (familyA)-[:HAS_FAMILY_MEMBER]->(childa:Child{name:"childA"}), 
       (familyA)-[:HAS_FAMILY_MEMBER]->(mothera:Mother{name:"motherA"}),
       (familyA)-[:HAS_FAMILY_MEMBER]->(fathera:Father{name:"fatherA"}),
       (fathera)-[:PARENT_TO]->(childa),
       (mothera)-[:PARENT_TO]->(childa)
CREATE (familyB:Family{name:"familyB"}),
       (familyB)-[:HAS_FAMILY_MEMBER]->(childb:Child{name:"childB"}), 
       (familyB)-[:HAS_FAMILY_MEMBER]->(motherb:Mother{name:"motherB"}),
       (familyB)-[:HAS_FAMILY_MEMBER]->(fatherb:Father{name:"fatherB"}),
       (fatherb)-[:PARENT_TO]->(childb),
       (motherb)-[:PARENT_TO]->(childb)
CREATE (familyA)-[:IS_NEIGHBOUR_TO]->(familyB), 
       (familyB)-[:IS_NEIGHBOUR_TO]->(familyA)

thank you so much for your detailed explain, yeah, which is great, everything is represented as point to point relationship:)

[flyly0755]

At the same time, I think of another question, the relationship between child and parents, now with neo4j is triangle model(3 points, 3 edges). But is there a new represention like T model? showed as below:

father---------mother
          |
          |
          |
         child