Spring Data Neo4j Repository for Relationship Entity

Question

I wish to query the RelationshipEntity like we query the NodeEntity.

Package Info:

groupId=org.springframework.data
artifactId=spring-data-neo4j
version=5.1.5.RELEASE

I have posted the dummy code below. Please don't mind if there are any mistakes or errors as long as the concept is clear.

NodeEntity (1) -> Employee

@NodeEntity("Employee")
public class Employee{

    @Id
    @GeneratedValue
    Long id;
    String name;

    // Id
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    // Name
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

    @Relationship(type = STARTED, direction = Relationship.OUTGOING)
    private List<Status> starts = new ArrayList<>();

    @Relationship(type = PAUSED, direction = Relationship.OUTGOING)
    private List<Status> pause = new ArrayList<>();

    @Relationship(type = STOPED, direction = Relationship.OUTGOING)
    private List<Status> stops = new ArrayList<>();

    @Relationship(type = COMPLETED, direction = Relationship.OUTGOING)
    private List<Status> action = new ArrayList<>();

    // Default Relationship
    @Relationship(type = ACTION, direction = Relationship.OUTGOING)
    private List<Status> action = new ArrayList<>();
}

NodeEntity (2) -> Project

@NodeEntity("Project")
public class Project{

    @Id
    @GeneratedValue
    Long id;
    String name;

    // Id
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    // Name
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

RelationshipEntity -> Status

@RelationshipEntity
public class Status {

    @Id
    @GeneratedValue
    Long id;
    String name;

    // Id
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    // Name
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

    @StartNode
    private Employee employee;

    @EndNode
    private Project project;
}

This Repository works perfectly fine

public interface EmployeeRepository extends CrudRepository<Employee, Long> {
    Employee findByName(String name);

    @Query("MATCH (e:Employee)-[r]->(p:Project) WHERE e.name={empName} AND p.name={prjName} RETURN e ")
    Employee getEmployeeWorkingOnProjectId(@Param("empName") String empName, @Param("prjName") String prjName);
}

This Repository does not works.
getEmployeeWorkingOnProject(String,String) returns NULL

I have made modifications after RETURN keyword, for example modifying it from RETURN * to the alias like RETURN e,r,p and also tried changing the sequence of the alias in the return as well.

I wish to get all the status (edges) associated with the specific employee and the specific project.

public interface StatusRepository extends CrudRepository<Status, Long> {

    @Query("MATCH (e:Employee)-[r]->(p:Project) WHERE e.name={empName} AND p.name={prjName} RETURN * ")
    Status getEmployeeWorkingOnProject(@Param("empName") String empName, @Param("prjName") String prjName);


    /* OR 
    @Query("MATCH (e:Employee)-[r]->(p:Project) WHERE e.name={empName} AND p.name={prjName} AND r.name={statusName} RETURN * ")
    Status getEmployeeWorkingOnProject(@Param("empName") String empName, @Param("prjName") String prjName, @Param("statusName") String statusName)
    */
}

CYPHER Result in Neo4j Browser:

(Replaced the real project image with test image)

Desired Outcomes (For example)

{
  Status: {
    name: ..,
    Employee: {
      ...
    },
    Project: {
      ...
    }
  }
},
{
  Status: {
    name: ..,
    Employee: {
      ...
    },
    Project: {
      ...
    }
  }
},
..

OR

STARTED : {
  Employee: {
    ...
  },
  Project: {
    ...
  }
},
STOPPED : {
  Employee: {
    ...
  },
  Project: {
    ...
  }
},

OR other kind of similar results where the Relationship entity holds both the connecting nodes.

Can your query get the correct results in the neo4j browser? — Liping Huang
Because I want to get specific employee's status not the status of everyone. — ViV

ViV ViV · Accepted Answer · 2020-06-30T17:04:45

I was able to make StatusRepository to work after removing the specific code from Employee (Model/Entity) mentioned below:

    @Relationship(type = STARTED, direction = Relationship.OUTGOING)
    private List<Status> starts = new ArrayList<>();

    @Relationship(type = PAUSED, direction = Relationship.OUTGOING)
    private List<Status> pause = new ArrayList<>();

    @Relationship(type = STOPED, direction = Relationship.OUTGOING)
    private List<Status> stops = new ArrayList<>();

    @Relationship(type = COMPLETED, direction = Relationship.OUTGOING)
    private List<Status> action = new ArrayList<>();

    // Default Relationship
    @Relationship(type = ACTION, direction = Relationship.OUTGOING)
    private List<Status> action = new ArrayList<>();

Spring Data Neo4j Repository for Relationship Entity

Desired Outcomes (For example)

1 Answers