How to fetch a subgraph of first neighbors in neo4j?

Question

I fetch first n neighbors of a node with this query in neo4j: (in this example, n = 6)

I have a weighted graph, and so I also order the results by weight:

START start_node=node(1859988)
MATCH start_node-[rel]-(neighbor)
RETURN DISTINCT neighbor,
rel.weight AS weight ORDER BY proximity DESC LIMIT 6;

I would like to fetch a whole subgraph, including second neighbors (first neighbors of first six children).

I tried smtg like :

START start_node=node(1859988)
MATCH start_node-[rel]-(neighbor)
FOREACH (neighbor | MATCH neighbor-[rel2]-(neighbor2) )
RETURN DISTINCT neighbor1, neighbor2, rel.proximity AS proximity ORDER BY proximity DESC LIMIT 6, rel2.proximity AS proximity ORDER BY proximity DESC LIMIT 6;

the syntax is still wrong but I am also uncertain about the output: I would like to have a table of tuples parent, children and weight: [node_A - node_B - weight]

I would like to see if it is performing better one query or six queries. Can someone help in clarifying how to iterate a query (FOREACH) and format the output?

thank you!

Answer 1

Ok, I think I understand. Here's another attempt based on your comment:

MATCH (start_node)-[rel]-(neighbor)
WHERE ID(start_node) IN {source_ids}
WITH
  neighbor, rel
ORDER BY rel.proximity
WITH
  collect({neighbor: neighbor, rel: rel})[0..6] AS neighbors_and_rels
UNWIND neighbors_and_rels AS neighbor_and_rel
WITH
  neighbor_and_rel.neighbor AS neighbor,
  neighbor_and_rel.rel AS rel
MATCH neighbor-[rel2]-(neighbor2)
WITH
  neighbor,
  rel,
  neighbor2,
  rel2
ORDER BY rel.proximity
WITH
  neighbor,
  rel,
  collect([neighbor2, rel2])[0..6] AS neighbors_and_rels2
UNWIND neighbors_and_rels2 AS neighbor_and_rel2
RETURN
  neighbor,
  rel,
  neighbor_and_rel2[0] AS neighbor2,
  neighbor_and_rel2[1] AS rel2

It's a bit long, but hopefully it gives you the idea at least