Question

I have a very simple issue, and I’m not sure if it’s a bug in hibernate, or an issue with JPA 2.0.

I have a simple @Entity

@Entity
public class LegacyClearanceNodeMapping {
    @Id    
    @ManyToOne
    @JoinColumn(name="nid")
    private LegacyNode clearanceNode;

    @ManyToOne
    @JoinColumn(name="rentable_nid")
    private LegacyNode rentableNode;

    @Column
    private Integer quality;

    ..snip..

}

Essentially, it’s a Many-to-many map class, but it has meta-data on the association, so I can’t treat it that way.

When I try to startup hibernate though, I get the follwoing error:

org.hibernate.MappingException: Could not determine type for: 
com.***.inventory.model.clearance.LegacyNode, at table: LegacyClearanceNodeMapping, for columns: [org.hibernate.mapping.Column(clearanceNode)]
    at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:292)
    at org.hibernate.mapping.SimpleValue.createIdentifierGenerator(SimpleValue.java:175)
    at org.hibernate.cfg.Configuration.iterateGenerators(Configuration.java:743)
    at org.hibernate.cfg.Configuration.generateDropSchemaScript(Configuration.java:854)
    at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:128)
    at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:91)

I can only suspect that Hibernate doesn’t like the PK being a fk, but I can’t change the schema.

Any known resolutions?

Thanks

Answer 1

You must have a basic property mapped as ID, and a ManyToOne mapped on the same column, and using the @MapsId annotation.