Does MERGE work the same for relationships as CREATE UNIQUE did?

merge.adoc

Merge for relationships

Does MERGE work the same for relationships as CREATE UNIQUE did?

It doesn’t seem to, and the way it is supposed to work causes an error (see query 4) This is based upon this blog post: http://blog.neo4j.org/2013/11/neo4j-200-rc1-final-preparations.html

Setup

CREATE (p1:Person{name:'Sam'}), (p2:Person{name:'Julie'})-[:HAS_ADDRESS]->(a1:Address{postcode:'bar'}), (p3:Person{name:'Bob'}), (p4:Person{name:'Sally'})-[:HAS_ADDRESS]->(a2:Address{postcode:'foo'}), (p5:Person{name:'Chris'}), (p6:Person{name:'Felicity'})-[:HAS_ADDRESS]->(a3:Address{postcode:'foo bar'})

CREATE UNIQUE, 2 relationships

MATCH (p1:Person{name:'Bob'}), (p2:Person{name:'Sally'}), (a:Address{postcode:'foo'})
CREATE UNIQUE (p1)-[:HAS_ADDRESS]->(a), (p2)-[:HAS_ADDRESS]->(a)
RETURN p1,p2,a

MERGE, 2 relationships

MATCH (p1:Person{name:'Sam'}), (p2:Person{name:'Julie'}), (a:Address{postcode:'bar'})
MERGE (p1)-[:HAS_ADDRESS]->(a), (p2)-[:HAS_ADDRESS]->(a)
RETURN p1,p2,a

MERGE, 1 relationship

This is how it was demoed in the blog post, but it just freezes if you uncomment the MERGE line! To see the error for this one, run query 1 in the console, then edit query 4 in the console, uncomment the MERGE line and run.

MATCH (p1:Person{name:'Chris'}), (a:Address{postcode:'foo bar'})
//MERGE (p1)-[:HAS_ADDRESS]->(a)
RETURN p1,a