CODEWITHSUNDEEP
collectionsneo4jcypher
kosmica
kosmica

Reputation: 23

Neo4j cypher - Compare two collections to get at least one same element

I want to return all users that I follow who are not members of any groups that I am in. If a followed user is a member of even one group that I am in, it should not be returned.

However, I am getting an error:

None.get

Neo.DatabaseError.Statement.ExecutionFailure

when I try this query:

MATCH (g1:groups)<-[:MEMBER_OF]-(u1:users{userid1:"56"})-[:FOLLOWS]->(u2:users)-[:MEMBER_OF]->(g2:groups)
WITH collect(g1.groupid) AS my_groups,u2,collect(g2.groupid) AS foll_groups
WHERE NOT any(t in foll_groups WHERE t IN extract(x IN my_groups))
RETURN u2

Upvotes: 1

Views: 748

Answers (1)

cybersam
cybersam

Reputation: 66989

Here is one solution:

MATCH (g1:groups)<-[:MEMBER_OF]-(u1:users { userid1:"56" })-[:FOLLOWS]->(u2:users)-[:MEMBER_OF]->(g2:groups)
WITH u2, collect(g2) AS foll_groups, collect(g1) AS my_groups
WITH u2, reduce(dup = FALSE, g IN foll_groups | (dup OR g IN my_groups)) AS has_dup
WHERE NOT has_dup
RETURN u2;

Upvotes: 3

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