Can a node contain a collection of relationships with the same end node?

I'm using Spring Data Neo4j 2.2.2 and I'm having trouble persisting multiple relationships with the same start and end node.

Assume a Person can have multiple Contracts with a Company. I modelled this as

public class Company {...}


public class Person {

    private Set<Contract> contracts;


public class Contract {

    private Person person;

    private Company company;

To add a contract to a person, I'm writing code like

Contract contract = new Contract();
// set other contract properties

where personDao is a GraphRepository<Person>.

In my tests, I can add a new Contract to a Person if that Person doesn't already have a Contract for the same Company. But if I try to add a new Contract to a Person with the same Company end node as an existing Contract it doesn't get saved.

equals() and hashCode() are implemented against @GraphId, and I've confirmed that all objects are in the Contract Set when I call save. I've also tried with Collection instead of Set to no avail.

Any idea what could be wrong?


The suggested way to create the 2nd relationship is as below

From reference manual

Note Spring Data Neo4j ensures by default that there is only one relationship of a given type between any two given entities. This can be circumvented by using the createRelationshipBetween() method with the allowDuplicates parameter on repositories or entities.

Contract createContractRelation(Company c, Person p)
    //last argument "true" indicates that a duplicate relationship should be created
    Contract contract = template.createRelationshipBetween(c, p, Contract.class, "Contract", true);


    return contract;

I was however able to create a maximum of only 2 relationships with this. More than two isn't working. I've an open question regarding this here: unable to create more than 2 same relations between two nodes

Another approach

I realized what you (and I) have is a Hypergraph situation. Neo4j only supports property graphs but there is a way to represent this using Neo4j as suggested in this cookbook.

Need Your Help

Jquery UI for button returns error

javascript jquery html jquery-ui

I am trying to apply JQuery UI for button but I can't achieve it. I am getting error like Error: TypeError: $(...).button is not a function. I have added a correct js library but it's not working.

FOSUserBundle Unit testing

symfony2 fosuserbundle

I am working on setting up a site with fosUserBundle. I need to write some unit tests, but I cannot seems to get authentication to work correctly for use with them. I have have tried a few methods ...

About UNIX Resources Network

Original, collect and organize Developers related documents, information and materials, contains jQuery, Html, CSS, MySQL, .NET, ASP.NET, SQL, objective-c, iPhone, Ruby on Rails, C, SQL Server, Ruby, Arrays, Regex, ASP.NET MVC, WPF, XML, Ajax, DataBase, and so on.