如何在Hibernate中使用两个表持久化自引用实体？

Question

I'm having a small and weird issue using Hibernate. I have two tables: "SERVICE" & SERVICE_RELATIONSHIP that defines a relationship between two services.

CREATE TABLE TMS.TB_SERVICE ( 
    ID_SERVICE  INTEGER NOT NULL,
    NAME        VARCHAR(255),
)


CREATE TABLE SERVICE_RELATIONSHIP ( 
    ID_SERVICE      INTEGER NOT NULL,
    ID_SERVICE_REL  INTEGER NOT NULL,
    RELATIONSHIP    VARCHAR(1)  // Could be 'E' (Exclude) or 'I' (Include)
    )

I use different methods (getInclude and getExclude) in order to get services depending on the type of relationship that they have. They work perfect, the only problem is when I want to persist a service , ID_SERVICE & ID_SERVICE_REL columns are inserted correctly but not RELATIONSHIP .

@Table(name="SERVICE")
public class Service implements Serializable {
    private String name;
    private Integer id;
    private Collection<Service> exclude;
    private Collection<Service> include;
     [..]
    @JoinTable(name = "SERVICE_RELATIONSHIP", 
      joinColumns = {
        @JoinColumn(name="ID_SERVICE", unique = false, updatable = true)
      },
      inverseJoinColumns = {
        @JoinColumn(name="ID_SERVICE_REL")
      }
    )
    @WhereJoinTable(clause = "RELATIONSHIP='E'")
    public Collection<Service> getExclude() {
        return exclude;
    }

    [..] 
    @OneToMany(fetch=FetchType.EAGER)
    @JoinTable(name = "SERVICE_RELATIONSHIP",
      joinColumns = {
        @JoinColumn(name="ID_SERVICE", unique = false, updatable = true)           
      },
      inverseJoinColumns = {
        @JoinColumn(name="ID_SERVICE_REL")
      }
    )
    @WhereJoinTable(clause = "RELATIONSHIP='I'")
    public Collection<Service> getInclude() {
        return include;
    }
}

Any ideas? Thanks in advance

Answer 1

@WhereJoinTable as the name describes, is only used for Where condition when doing a join on a select clause.

You have a couple of options to implement this.

1. Map the relationship as a class.
2. Create an include and exclude tables.

Personally, I would map the relationship class, but I would keep it hidden from outside Service , so the code that uses service is not aware of the relationship class.