CODEWITHSUNDEEP
neo4jcypher
Mateus Vahl
Mateus Vahl

Reputation: 989

Neo4j Sort by whom I follow, who follows me, others

Let's suppose a social network

Code at ne4j console: http://console.neo4j.org/?id=fij8qs

CREATE (p1:PERSON {name: "Edson"})
CREATE (p2:PERSON {name: "Clades"})
CREATE (I:PERSON {name: "Mateus"})
CREATE (other:PERSON {name: "Goku"})

CREATE (alb:ALBUM {name: "Férias"})

CREATE I-[:HAVE_ALBUM]->alb
CREATE I-[:FOLLOW]->p1

CREATE p1-[:LIKE]->alb
CREATE p2-[:LIKE]->alb
CREATE other-[:LIKE]->alb

HOW: select all people who likes the album. order by my friends after by friends of my friends, then by any other.

Select all that [:LIKE] my album ORDER BY

I-[:FOLLOW]
p2-[:FOLLOW]->person-[:LIKE]->alb // friend of my friend
person-[:LIKE]->alb //other

similar question [Cypher: Is it possible to find creepy people following my friends?

Upvotes: 0

Views: 69

Answers (1)

Stefan Armbruster
Stefan Armbruster

Reputation: 39915

You need to use an optional match with variable length to know the distance between you and the likers of the album and then sort by distance:

MATCH (person)-[:LIKE]->(:ALBUM {name:"Férias"}), (me:PERSON {name:"Mateus"})
OPTIONAL MATCH p=(me)-[:FOLLOW*]->(person)
WITH person, coalesce(length(p), 9999) AS distance
RETURN person, distance
ORDER BY distance

The coalesce assigns a high value of 9999 to everyone you don't follow directly or indirectly.

Upvotes: 2

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