JPA映射MAP <Entity, Embedable>

Question

I've 2 classes:

@Entity
@Table(name = "es_item")
public class Item {
    @Id
    @Column(name= "inventory_item_id")
    public int getInventoryItemID(){
        return inventoryItemID;
    }

    @ElementCollection(targetClass = ItemConversionAttributes.class, fetch = FetchType.LAZY)
    @MapKeyJoinColumn(name="component_item_id", referencedColumnName = "inventory_item_id")
    @CollectionTable(name="es_bom_levels", joinColumns = @JoinColumn(name = "inventory_item_id"))
    public Map<Item, ItemConversionAttributes> getConversionAttributes(){ return conversionAttributes; }
}

@Embeddable
public class ItemConversionAttributes {
    @ManyToOne(targetEntity=Item.class)
    @JoinColumn(name="component_item_id", insertable=false, updatable=false)
    @NotFound(action=NotFoundAction.IGNORE)
    public Item getComponentItem(){ return componentItem; }
}

The structure of db is
es_item has columns: inventory_item_id is key, some orther columns.
es_bom_level has columns: inventory_item_id, component_item_id. with component_item_id is fk to es_item.
the my mapping does not work. I see the error
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: vmjboss7] Unable to build EntityManagerFactory at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:914) at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:889) at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:73) at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.createContainerEntityManagerFactory(PersistenceUnitServiceImpl.java:162) at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.start(PersistenceUnitServiceImpl.java:85) at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA.jar:1.0.2.GA] at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA.jar:1.0.2.GA] ... 3 more Caused by: org.hibernate.MappingException: Repeated column in mapping for collection: com.biz.model.Item.conversionAttributes column: component_item_id at org.hibernate.mapping.Collection.checkColumnDuplication(Collection.java:341) at org.hibernate.mapping.Collection.checkColumnDuplication(Collection.java:364) at org.hibernate.mapping.Collection.validate(Collection.java:321) at org.hibernate.mapping.IndexedCollection.validate(IndexedCollection.java:89) at org.hibernate.cfg.Configuration.validate(Configuration.java:1298) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1742) at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:84) at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:904)
Please help me.

Answer 1

Sorry for the delay in response as I was stuck with other issues :-(

Please try the below code:-

@Entity
@Table(name = "es_item")
public class Item {
    @Id
    @Column(name= "inventory_item_id")
    private int inventoryItemID;    

    @ElementCollection(fetch = FetchType.LAZY)   
    @CollectionTable(name="es_bom_levels", joinColumns = @JoinColumn(name = "component_item_id"))
    @MapKeyJoinColumn()
    public Map<Item, ItemConversionAttributes> conversionAttributes;

    ......
    // getters and setters
}

@Embeddable
class ItemConversionAttributes {

    @ManyToOne(targetEntity=Item.class)
    @JoinColumn(name="inventory_item_id", insertable=false, updatable=false)
    @NotFound(action=NotFoundAction.IGNORE)
    private Item componentItem;

    ..........
    // getters and setters
}

A catch here is that this setup creates an additional column and constraint in you es_bom_levels table which is as expected (my guess) after I went through the below blog

mappingembeddable