neo4j cypher count relations between same type of nodes

Question

I am too new in graph databases and I have a problem in getting data from model like this.

I am trying to count common likes between User1 and all other users in same group as user1. Here is the result I am trying to get for User1 :

User , Count, Drinks
User3,     2, [ Cola, Beer ]
User2,     1, [ Cola ]
User5,     1, [ Tea ]
User4,     0, [ ]
User6,     0, [ ]

It seems easy task to do but not for me.

I can get the users and counts with users having relations with but not with users without relations. Please can anyone help me with this? Thanks in advance!

Answer 1

The solution I propose has the following logic :

• Find the user 1
• Find other users that are not user 1
• Find an OPTIONAL MATCH for a path between user1, a drink and the current iteration of the other user

This is based on the following test graph :

http://console.neo4j.org/r/xc3cqt

The query :

MATCH (u:User { id:1 })
MATCH (o:User)
WHERE o <> u
OPTIONAL MATCH (u)-[r:LIKES]->(d)<-[:LIKES]-(o)
RETURN o.id, count(r) as c, collect(DISTINCT (d.name)) AS drink

Result for your provided graph :

o.id    c           drink
2       1           [Cola]
5       1           [Tea]
4       0           []
3       2           [Beer, Cola]
6       0           []