how do I delete duplicate relationships between tw

问题:

When I run this query:

START n1=node(7727), n2=node(7730)
MATCH n1-[r:SKILL]->n2 RETURN r

it gives me a list of duplicate relationships that I have between the two nodes. what do I add to the cypher query to iterate over the relationship to keep one relationship and delete the rest?

回答1:

To do this for two known nodes:

start n=node(1), m=node(2) match (n)-[r]->(m) 
with n,m,type(r) as t, tail(collect(r)) as coll 
foreach(x in coll | delete x)

To do this globally for all relationships (be warned this operation might be very expensive depending on the size of your graph):

start r=relationship(*) 
match (s)-[r]->(e)
with s,e,type(r) as typ, tail(collect(r)) as coll 
foreach(x in coll | delete x)