After Update to Spring Boot 2.4.1 , not able to fetch parent Object using custom query [DATAGRAPH-1473]

[spring-projects-issues]

wolfy027 opened DATAGRAPH-1473 and commented

Custom Query used in AnimalRepository > @Query: 

 

MATCH path=(n:Animal {uuid: $id})-[:`PARENT`*0..]->() RETURN path

Spring Boot Version before update : 2.3.4

Spring Boot Version before update : 2.4.1

 

Domain reference:

 

@Node
@JsonSerialize(as = Animal.class)
@JsonDeserialize(as = Animal.class)
public class Animal{
@Id
@GeneratedValue(generatorClass = GeneratedValue.UUIDGenerator.class)
private UUID uuid;
 
@Relationship(type = "PARENT", direction = Relationship.Direction.OUTGOING)
private Animal parent;
..
..
}

 

 

All the other properties are parsed except for parent which is null for any animal.

 

 

---

Affects: 6.0.2 (2020.0.2)

[robin850]

Hello,

I had a similar issue. Basically, with something like this:

@Node
class Technology {
    private String name;
}

@Node
class Application {
    @Relationship("RELIES_ON")
    private List<Technology> technologies;
}

Then, on the repository side, trying to fetch an application and its technologies would return the application but with an empty set of technologies:

@Query("MATCH (a:Application)" +
        " OPTIONAL MATCH (a)-[r:RELIES_ON]->(t:Technology)" +
        " RETURN a, r, t")
List<Application> fooBar(String name);

It can be fixed this by using COLLECT(r), COLLECT(t). Fetching and collecting the relationship part (even though it is not mapped to an @RelationshipProperties class) is important ; the list is empty with only COLLECT(t) even though that's what matters here.

Also, it looks like the behavior changed even for 1:1 mapping in this version (e.g. this ticket on SO).

I don't know if it is expected or not but maybe the documentation could be improve at this level as there seems to be behavioral differences between the previous SDN/OGM and SDN 6 regarding relationships.

[meistermeier]

You are right in both cases @robin850: You need to make use of the COLLECT function in order to provide a single result in contrast to a cartesian product. And yes, this is for sure some documentation missing on this bit. There is already an issue for this, so I will close this issue as it now is only a duplicate of #2032

[wolfy027]

Thanks, the issue got solved with the updated query suggested by @robin850

[wolfy027]

MATCH (c:Animal {uuid: $id}) OPTIONAL MATCH (c)-[r:PARENT]->(p:Animal) RETURN c,collect(r),collect(p)

This gives me response with attributes of current node and it's parent's nodes, but it skips the grand-parent's attributes.

MATCH (c:Animal {uuid: $id}) OPTIONAL MATCH (c)-[r:PARENT*]->(p:Animal) RETURN c,collect(r),collect(p) does'nt work

What should be the suggested change? @robin850 @meistermeier

[meistermeier]

Before I open up a new issue on this one: Could you set the SDN version to 6.0.3 in your pom?
There were several fixes targeting inheritance.