How to map query result

[wurangbo]

Hi guys，
I want to map query result to a polo object, In SDN4, I can use annotation @QueryResult .
But in SDN6, how to ?

Repository

public interface DeviceNodeRepository extends Neo4jRepository<DeviceNode, Long> {
    Query("MATCH (a:DeviceNode)-[r:CUSTOMER*]->(b:DeviceNode)   where b.deviceId={deviceId} return  a  as relatedNodes, r as nodeRelations, b as sourceNode")
    DeviceNodeConnectionResult getNodesByDeviceId(Param("deviceId") Integer deviceId);
}

public class DeviceNodeConnectionResult {
    private DeviceNode sourceNode;
    private List<DeviceNodeRelation> nodeRelations;
    private  List<DeviceNode> relatedNodes;
}

I defined an object to map, but got null

[gerrit_meier]

There is no replacement for the QueryResult in combination with repositories. Those repositories work strictly by the rules of the modeled domain classes.
For your use-case, you could for example do following:

public class DeviceNode {
// id etc.
  @Relationship("CUSTOMER")
  private List<DeviceNode> relatedNodes;
}

and a query like

MATCH (a:DeviceNode)-[r:CUSTOMER*]->(b:DeviceNode)
where b.deviceId={deviceId}
return a, collect(r), collect(b)

This will create a mapped chain of DeviceNodes which seems like an even better representation of the graph in the application.

If you strictly want to stick with a looks-like-QueryResult, more information can be found here:

github.com/spring-projects/spring-data-neo4j

Difficulty mapping InternalNodes to domain model objects in custom queries

opened 07:03AM - 15 Jun 21 UTC

closed 08:31AM - 15 Jun 21 UTC

alizadehei

status: waiting-for-triage

I have a class with the following structure: ``` @NoArgsConstructor @Setter… @Getter @Node public class Person { @Id @GeneratedValue(GeneratedValue.UUIDGenerator.class) private UUID id; @Property private String name; @Property private String family; @Property private int age; public Person(String name, String family, int age) { this.name = name; this.family = family; this.age = age; } } ``` I want to do a custom query like the following query: `MATCH (n:Person) return count(n) as count, n ` I did this query using the neo4jClient and neo4jTemplate in different ways (mentioned below): ``` template.save(new Person("Reza" + new Random(System.currentTimeMillis()).nextInt(), "Mahdavi", 22)); // 1- List<Person> result_1 = template.find(Person.class).matching("Match(n:Person) return count(n) as count,n").all(); // 2- Collection<Person> result_2 = client.query("Match(n:Person) return count(n) as count,n").fetchAs(Person.class).all(); // 3- Collection<Map<String, Object>> result_3 = client.query("Match(n:Person) return count(n) as count,n").fetch().all(); ``` Query 1 return a List of Persons without count record. Query 2 throw an exception Query 3 return a list of maps that map values are InternalNode not Person. in fact, the problem is that Person nodes are returned as InternalNodes, not Person. As a result, we need to manually map the InternalNodes to the domain model objects. This is while in the Neo4j-ogm; The output of the session.query("") was a QueryResultModel whose result field was one list of maps that map values were Person. How do I make a custom query that returns InternalNodes automatically mapped to the domain model objects؟

github.com/spring-projects/spring-data-neo4j

Deterministic mapping of records with mixed results

opened 01:23PM - 06 May 21 UTC

closed 03:28PM - 06 May 21 UTC

meistermeier

type: enhancement

Since we do not officially support this, I would call this an enhancement instea…d of a bug fix ;) Given that we want to map something like ``` MATCH (a:DatabaseObject{dbId:$dbId})-[r:output]->(m:PhysicalEntity) RETURN m, r.stoichiometry as n ``` the mapping mechanism will create a `Map` that will only contain the identifier and the node description of the template / repository. If this node description is an (abstract) parent class, we will then lose the information about the concrete type coming from the node's label.

SpringBoot Projection/@QueryResult not working Spring Data Neo4j & Neo4j-OGM

Hi, I'm new to Neo4j! I'm currently working on a simple REST API but I cannot seem to figure out how to return both nodes and relations in a single endpoint. My design is super simple. I have a bunch of different resource nodes [CLIENT, SERVER, DB] (which all inherit from RESOURCE) and a PROJECT node that connects them. The resource nodes have connections between them and every resource connects to exactly one Project. An example from the Neo4j Browser is attached (this is my entire DB right no…

github.com/spring-projects/spring-data-neo4j

Replacement of @QueryResult

opened 01:54PM - 11 Mar 21 UTC

closed 06:52AM - 12 Mar 21 UTC

panxianhaoo

status: waiting-for-triage

In Spring Data Neo4j 6.0.5 I can't find @Queryresult. How can I map a result ret…urned from neo4j.

[wurangbo]

Hi guys,
And now， I can't define a custom query in DeviceNodeRepository interface. Otherwise, the following exception will be caught “ No property customQuery found for type DeviceNode!”
@Query("MATCH (a:DeviceNode)-[r:CUSTOMER*]->(b:DeviceNode) where b.deviceId={deviceId}
return collect(a) + collect(b) as relatedNodes")
List findByCustomQuery(@Param("deviceId") Integer deviceId);

it means I can only use Neo4jClient to implement custom queries. is there any code for reference？
THX

[gerrit_meier]

You have to use another name. The method naming pattern findBy with CustomQuery you have used would start a search for the property customQuery on the DeviceNode.
(Mostly) Everything else than findBy at the beginning of the method name will work.
Also you should not concatenate the lists but return a, collect(r) and collect(b) as separated parts of the record as mentioned above.

[wurangbo]

gerrit.meier:

You have to use another name. The method naming pattern findBy with CustomQuery you have used would start a search for the property customQuery on the DeviceNode .
(Mostly) Everything else than findBy at the beginning of the method name will work.
Also you should not concatenate the lists but return a , collect(r) and collect(b) as separated parts of the record as mentioned above.

hi， Ihave tried as bellow.
@Query("MATCH (a:DeviceNode)-[r:CUSTOMER*]->(b:DeviceNode) where b.deviceId={deviceId} return (collect(a) + collect(b)) as relatedNodes")
List findRelationNode(@Param("deviceId") Integer deviceId);
but get the same error.
No property findRelationNode found for type DeviceNode!

[wurangbo]

Hi @gerrit.meier ,
I have solved this issue of finding node.
//get DeviceNode OK
Query("MATCH (a:DeviceNode)-[r:CUSTOMER*]-(b:DeviceNode) where b.deviceId=$deviceId return (collect(a) + collect(b)) as relatedNodes")
List findRelationNode(Param("deviceId") Integer deviceId);
//get deviceNodeRelation throw exception " Could not find mappable nodes or relationships inside
Query("MATCH (a:DeviceNode)-[r:CUSTOMER*]-(b:DeviceNode) where b.deviceId=$deviceId return collect(r) as nodeRelations ")
List findRelationNodeRelation(Param("deviceId") Integer deviceId);
How can I get noderelationship?

[gerrit_meier]

The relationships cannot exist on their own but need to be attached to the entities. In your case a and b. That's why I said that you would have to use the return pattern mentioned above.