Creating a node in neo4j with one unique property other than ID

问题

My Project is based on Spring boot + Neo4j . I am trying to create a new Privilege node , but don't want to duplicate Privilege.

Now I have a UserRole node which is holds List<Privilege>. Now I want that when I create a Privilege , it check first is another Privilege exists with same privilegeName property.

Below are my domain classes.

UserRole Class

 @NodeEntity
public class UserRole {

    public UserRole(User user, Role role) {
        this.user = user;
        this.role = role;
    }

    /**
     For Jackson Parsing
     **/
    public UserRole() {
    }

    @GraphId
    private Long id;

    public UserRole(User user, Role role, Unit unit) {
        this.user = user;
        this.role = role;
        this.unit = unit;
    }



    public long getId() {
        return id;
    }

    @Relationship(type = HAS_USERROLE,direction = "OUTGOING")
    User user;
    public User getUser() {
        return user;
    }

    @Relationship (type = HAS_ROLE_OF,direction = "OUTGOING")
    Role role;
    public Role getRole() {
        return role;
    }


    @Relationship(type = "WORKS_IN",direction = "OUTGOING")
    Unit unit;

    public Unit getUnit() {
        return unit;
    }

    public void setUnit(Unit unit) {
        this.unit = unit;
    }

    @Relationship(type = "HAS_PRIVILEDGE", direction = "OUTGOING")
    List<Priviledge> priviledgeList;

    public List<Priviledge> getPriviledgeList() {
        return priviledgeList;
    }

     public void setPriviledgeList(List<Priviledge> priviledgeList) {
        this.priviledgeList = priviledgeList;
      }
    }

Privilege Class

  @GraphId
    Long id;


    private String priviledge;

    private String priviledgeOn;
    private Long priviledgeOnId;

    public Priviledge() {
    }

    public Priviledge(String priviledge, String priviledgeOn) {
        this.priviledge = priviledge;
        this.priviledgeOn = priviledgeOn;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getPriviledge() {
        return priviledge;
    }

    public void setPriviledge(String priviledge) {
        this.priviledge = priviledge;
    }

    public String getPriviledgeOn() {
        return priviledgeOn;
    }

    public void setPriviledgeOn(String priviledgeOn) {
        this.priviledgeOn = priviledgeOn;
    }

    public Long getPriviledgeOnId() {
        return priviledgeOnId;
    }

    public void setPriviledgeOnId(Long priviledgeOnId) {
        this.priviledgeOnId = priviledgeOnId;
      }
    }

I am Using GraphRepository to save Entities.

回答1:

The only way to do this currently is to query for the Privilege existing first and then create it if not, or use it if it does. Also add a unique constraint to be safe.

In a future release, this use case will be supported.

来源：https://stackoverflow.com/questions/39263922/creating-a-node-in-neo4j-with-one-unique-property-other-than-id