Fetch a tree with Neo4j -


given forest of trees in neo4j rest server, i`m trying return single tree given root vertex.

being each tree quite large, need de-duplicated list of vertices , edges in order able reconstruct full tree on client side.

i tried multiple combinations around match (r:root)-[*]->() return path starting root, lots of duplicates:

match p = (r:root)-[*]->(x) return nodes(p) vertices, rels(p) edges";

this returns each , every path follows, repeating each node every time:

a->b a->b->c a->b->c->d

etc...

instead, need result having

{     vertices: [a, b, c, d],     edges: [[a, b], [b, c], [c, d]] }

i'm using node.js seraph, if relevant, i`m not strictly bound library.

so first off, might want add where clause make sure path ending leaf:

match p = (r:root)-[*]->(x) not(x-->()) return nodes(p) vertices, rels(p) edges";

so secondly, if want of nodes , relationships in 1 go, may need execute 2 queries:

match p = (r:root)-[*]->(x) not(x-->()) unwind nodes(p) vertex return distinct vertex;  match p = (r:root)-[*]->(x) not(x-->()) unwind rels(p) edge return distinct startnode(edge), endnode(edge);

update (michael)

match p = (r:root)-[*]->(x) not(x-->()) unwind nodes(p) vertex collect(distinct vertex) nodes, p unwind rels(p) edge return nodes, collect(distinct edge) rels

update2 (michael)

i found more compact way

match p = (:root)-[r*]->(x) return collect(distinct id(x)) nodes, [r in collect(distinct last(r)) | [id(startnode(r)),id(endnode(r))]] rels

if want include root node, use *0..


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