neo4j RelationshipEntity not created

Question

I'm having issues getting a neo4j RelationshipEntity persisted with Spring Boot. I'm using spring-boot-starter-data-neo4j (2.1.0.RELEASE), and the neo4j docker image tagged 3.4.9.

I have a simple NodeEntity, which contains a collection for the RelationshipEntity:

@NodeEntity
public class Book {
    @Id
    @GeneratedValue
    private Long id;
    private String name;

    public Book() {}

    public Book(String name) {
        this.name = name;
    }

    @Relationship(type = "PURCHASED_WITH", direction = "OUTGOING")
    private Set<BookPurchase> purchases = new HashSet<>();

    // getters and setters follow
}

I have another NodeEntity, which also contains a collection for the relationship entity:

@NodeEntity
public class CreditCard {

    @Id
    @GeneratedValue
    private Long id;
    private String number;

    @DateString(value = "yyyy-MM-dd")
    private Date expiryDate;

    public CreditCard() {}

    public CreditCard(String number, Date expiryDate) {
        this.number = number;
        this.expiryDate = expiryDate;
    }

    @Relationship(type = "PURCHASED_WITH", direction = "INCOMING")
    private Set<BookPurchase> purchases = new HashSet<BookPurchase>(); 

    // getters and setters follow
}

I have the RelationshipEntity, which adds references to both NodeEntity classes in the constructor:

@RelationshipEntity(type = "PURCHASED_WITH")
public class BookPurchase {
    @Id
    @GeneratedValue
    private long id;

    @DateString("yyyy-MM-dd")
    Date purchaseDate;

    @StartNode
    private Book book;

    @EndNode
    private CreditCard card;

    public BookPurchase(){}

    public BookPurchase(CreditCard card, Book book, Date purchaseDate) {
        this.card = card;
        this.book = book;
        this.purchaseDate = purchaseDate;

        this.card.getPurchases().add(this);
        this.book.getPurchases().add(this);
    }
    // getters and setters follow
}

And finally I have the Spring controller tying everything together:

@RestController
public class ExamplesController {

    @Autowired
    CreditCardRepository creditCardRepository;

    @PostMapping(value="/purchases")
    public String createPurchases() {
        CreditCard card = new CreditCard("11111", new GregorianCalendar(2018, Calendar.FEBRUARY, 12).getTime());

        Book book1 = new Book("of mice and men");
        BookPurchase purchase1 = new BookPurchase(card,book1,new GregorianCalendar(2018, Calendar.MARCH, 15).getTime());

        creditCardRepository.save(card);
        return "Successfully created entities";
    }
}

Whenever I try to curl -X POST http://localhost:8080/purchases, I just see the following in the neo4j browser - the RelationshipEntity is not persisted, only the nodes.

Can anyone assist?

What does MATCH (n) OPTIONAL MATCH ()-[r]->() RETURN * return? Your shown query only returns nodes, and by default (depending on Neo4j version), auto relation linking in the browser is turned off (and you didn't say if you clicked the expand relationships button at the bottom of the circle of options) — Tezra
@Tezra thanks for your reply. I get the same result with the above query. Additionally, the browser highlights there are 'No relationships in database' under the 'Database information' view — dwaynetherock

dwaynetherock dwaynetherock · Accepted Answer · 2018-11-18T04:40:06

Thanks to Gerrit Meier for answering this one. My RelationshipEntity was using the primitive long instead of the object/wrapper Long. Complete details here: https://community.neo4j.com/t/neo4j-relationshipentity-not-persisted/3039

neo4j RelationshipEntity not created

1 Answers