In SDN4 neo4jOperations.queryForObjects returns entities with empty collections. How to solve?

Question

I have entity, which looks like this:

@NodeEntity
class User {
    String name;
    boolean male;
    <...>
    @Relationship(type = "friend")
    Set<User> friends;
    @Relationship(type = "participation")
    Set<Event> events;
    <...>
}

In order to query male users I use the following code:

String q = "MATCH (u:User) WHERE u.male=true RETURN u";
Iterable<User> maleUsers = neo4jOperations.queryForObjects(User.class, q, emptyMap());

But it returns users with empty collections of friends and events.

Trying to fix the problem I got the following code:

String q = "MATCH (u:User) WHERE u.male=true WITH u MATCH p=(u)-[*0..1]-() RETURN p";
Iterable<User> maleUsers = neo4jOperations.queryForObjects(User.class, q, emptyMap());

And now collections are initialized. But this change brings a new problem:

• This code is intended to return: only male users
• But in fact it returns: male users and users, somehow related to male users

How to solve my problem properly? Any thoughts are very appreciated!

PS: I use Spring Data Neo4j 4.1.0.M1.

Answer 1

This is because you return a path which contains many User entities, and the OGM is unable to tell which one you want back. The best way to do this would be to use session.query:

Result result = session.query("MATCH (u:User) WHERE u.male=true WITH u MATCH p=(u)-[*0..1]-() RETURN u as user, nodes(p),rels(p)",emptyMap());

and then from result, retrieve each user which will have friends and events mapped.