CODEWITHSUNDEEP
pythonneo4jcypherpy2neoedges
lo tolmencre
lo tolmencre

Reputation: 3934

py2neo establish new edges between existing nodes

Let's say I wanted to merge new edges into my graph between 2 adjacent nodes (so that after the operation the edges in question are doubled so to speak).

I have the following record returned by graph.cypher.execute(<some query>):

   | p                         
---+----------------------------
 1 | (:A)-[:r]->(:B)-[:r]->(:C)

Now I would like to double the edges (A,B) and (B,C). For that i wrote this code:

for record in graph.cypher.execute(<some query>):
    for rel in record[0]:
            self.graph.cypher.execute("MERGE "+str(self.graph.node(rel.start_node.ref))+"-[:new]->"+str(self.graph.node(rel.end_node.ref)))

However, I do not get new edges between the existing nodes but two new relationships with a total of 4 new nodes, because apparently NEO4J does not interpret str(self.graph.node(rel.start_node.ref)) and str(self.graph.node(rel.end_node.ref)) as referring to the existing nodes in the graph. How can I remedy this?

Upvotes: 1

Views: 689

Answers (1)

lo tolmencre
lo tolmencre

Reputation: 3934

self.graph.create(rel(r.start_node, "new", r.end_node)) does it.

needs from py2neo import rel

Upvotes: 1

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