apoc.create.vRelationship
Function APOC Core
apoc.create.vRelationship(nodeFrom,'KNOWS',{key:value,…}, nodeTo) returns a virtual relationship
Signature
apoc.create.vRelationship(from :: NODE?, relType :: STRING?, props :: MAP?, to :: NODE?) :: (RELATIONSHIP?)Input parameters
| Name | Type | Default |
|---|---|---|
from |
NODE? |
null |
relType |
STRING? |
null |
props |
MAP? |
null |
to |
NODE? |
null |
Usage Examples
The examples in this section are based on the following graph:
CREATE (s1:Student {name: 'Priya'})
CREATE (s2:Student {name: 'Joachim'})
CREATE (s3:Student {name: 'Dominic'})
CREATE (s4:Student {name: 'Amir'})
CREATE (s5:Student {name: 'Natasha'})
CREATE (s6:Student {name: 'Elena'})
CREATE (t1:TestScore {score: 87})
CREATE (t2:TestScore {score: 90})
CREATE (t3:TestScore {score: 78})
CREATE (t4:TestScore {score: 84})
CREATE (t5:TestScore {score: 76})
CREATE (t6:TestScore {score: 92})
CREATE (a:Level {level: 'beginner'})
CREATE (b:Level {level: 'intermediate'})
CREATE (c:Level {level: 'advanced'})
MERGE (s1)-[:HAS]->(t1)-[:ASSIGNED_TO]->(b)
MERGE (s2)-[:HAS]->(t2)-[:ASSIGNED_TO]->(c)
MERGE (s3)-[:HAS]->(t3)-[:ASSIGNED_TO]->(a)
MERGE (s4)-[:HAS]->(t4)-[:ASSIGNED_TO]->(b)
MERGE (s5)-[:HAS]->(t5)-[:ASSIGNED_TO]->(a)
MERGE (s6)-[:HAS]->(t6)-[:ASSIGNED_TO]->(c);The apoc.create.vRelationship offers both a procedure and function version, so we can create the virtual relationships independently or return them based on results of a query.
For instance, we might want to create virtual relationships between students to see which students have the same understanding level of class material:
apoc.create.vRelationship Procedure
MATCH (s1:Student)-[:HAS]->(:TestScore)-[:ASSIGNED_TO]->(l:Level)<-[:ASSIGNED_TO]-(:TestScore)<-[:HAS]-(s2:Student)
CALL apoc.create.vRelationship(s1,'SIMILAR_LEVEL',{level: l.level},s2) YIELD rel
RETURN s1, rel, s2;
Figure 1. Results
We could also create a virtual relationship straight to their level and use the function version of the apoc.create.vRelationship.
apoc.create.vRelationship Function
MATCH (s1:Student)-[:HAS]->(:TestScore)-[:ASSIGNED_TO]->(l:Level)
RETURN s1, apoc.create.vRelationship(s1,'HAS_UNDERSTANDING',{},l) as rel, l
Figure 2. Results