CODEWITHSUNDEEP
graphneo4jspring-data-neo4j
Prakash P
Prakash P

Reputation: 4058

Get relationship between nodes

I have this following type of graph which I get using this query:

MATCH (p:Person)-[:REPORTS_TO *]->(c:Person) WHERE p.name="F"
WITH COLLECT (c) + p AS all 
UNWIND all as p MATCH (p)-[:REPORTS_TO]-(c) 
RETURN p,c;

enter image description here

Use-Case:

1. I want to find what level is a node at with respect to node F? Example :

    Node `D`, `E` are direct child of `F`, hence they are at level 1
    
    Node `A,B,C` are childs of `D` (which is child of `F`) hence level 2
    
    Node `X` is child of `A' (which is at level 2), hence level 3

and so onnnnn....

I tried to solve this by introducing a variable i and increment it with each iteration (but it didn't worked).

MATCH (p:Person)-[:REPORTS_TO *]->(c:Person) WHERE p.name="F"
WITH COLLECT (c) + p AS all ,i:int=0
UNWIND all as p MATCH (p)-[:REPORTS_TO]->(c) 
RETURN p,c, i=i+1;

2. Given two nodes find relation between then

e.g Find relation between F and X?

Expected answer = 3 (as it is at level 3)

How should I proceed to solve these use-cases?

Note : Graphical response from Neo4j server isn't necessarily needed , Json response will also be fine.

Upvotes: 0

Views: 109

Answers (1)

František Hartman
František Hartman

Reputation: 15086

UC1 Use Path and length(p) function

MATCH p=(root:Person)-[:REPORTS_TO *]->(child:Person) 
WHERE root.name="F"
RETURN nodes(p)[-2], nodes(p)[-1],length(p)

This will find all paths from root node, and return pairs of second to last and last nodes + level you want.

nodes(p) - list of nodes on path p

[-2] - second node from the end of the list

UC2: use shortestPath function:

MATCH (p1:Person),(p2:Person)
WHERE p1.name = '..' AND p2.name = '...'
MATCH p=shortestPath((p2)-[:REPORTS_TO*]->(p2))
RETURN length(p)

Upvotes: 2

Related Questions