Wrong SQL for view object using Hibernate Annotations

Question

I'm working on a hibernate entity mapping for a database view; when I do a criteria query against it, hibernate is generating bad SQL. Any help figuring out what the problem is with my mapping would be greatly appreciated!

I have two mapped entities which I am trying to grab from a database view; the view has no other columns, just the FK of each entity. One of these FK's can be treated as a primary key, since the view has a row for each primary entity. So my DB schema for the view looks like:

primary(primary_id, some_other_fields)
history(history_id, primary_id, some_other_fields)
view_latest_status_history(primary_id, history_id)

Note the view is used because I want to pick out only the latest history for each primary, not all mapped history records. Here is the object I am using for the view, with entity annotations:

@Entity
@org.hibernate.annotations.Entity(dynamicUpdate = true)
@Table(name = "view_latest_status_history")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class ViewLatestStatusHistoryRow implements Serializable {
    private Primary primary;
    private History history;

    /**
     * @return Returns the history.
     */
    @ManyToOne(cascade = { CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REMOVE }, fetch = FetchType.LAZY)
    @JoinColumn(name = "history_id", nullable = true)
    @AccessType("field")
    public History getHistory() {
        return history;
    }

    //equals() and hashCode() implementations are omitted

    /**
     * @return Returns the primary.
     */
    @Id
    @ManyToOne(cascade = { CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REMOVE }, fetch = FetchType.LAZY)
    @JoinColumn(name = "primary_id", nullable = false)
    @AccessType("field")
    public Primary getPrimary() {
        return primary;
    }
}

Both the Primary and History objects have complete, working entity annotations.

My criteria setup:

criteria.add(Restrictions.in("primary", [collection of primary objects]));
criteria.setFetchMode("primary", FetchMode.JOIN);
criteria.setFetchMode("history", FetchMode.JOIN);

And the (wrong) generated SQL:

select this_.primary as primary78_1_, this_.primary_id as prim2_78_1_, primary2_.history_id as unique1_56_0_, ...history fields
from DB_CATALOG.dbo.view_latest_status_history this_ 
left outer join DB_CATALOG.dbo.history primary2_ on this_.primary_id=primary2_.primary_id 
where this_.specChange in (?, ?...)

I might've mucked up a few things when editing out the specifics of our project's DB schema, but the point is the first field in the 'select' clause is wrong:

this_.primary (view_latest_status_history.primary) is not a field; the field should be called primary_id. I think this may have something to do with the @Id annotation on the primary field? Any ideas how to fix this? If I remove the @Id, I get an error telling me that the entity has no primary key.

Update:

I no longer map the view as a field using a join table notation (as suggested below). The annotations have been revised, as follows. This solution works correctly in HQL, and generates the expected schema when hbm2ddl is enabled, but I have not re-tested it using the criteria query.

@Entity
@Table(name = "view_latest_status_history")
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class ViewLatestStatusHistoryRow implements Serializable {
    private String id;
    private Primary primary;
    private History history;

    /**
     * @return Returns the history.
     */
    @OneToOne(optional = true)
    @JoinColumn(name = "history_id", nullable = true)
    @AccessType("field")
    public History getHistory() {
        return history;
    }

    //equals() and hashCode() implementations are omitted

    @Id
    @Column(name = "primary_id", nullable = false)
    @Override
    @AccessType(value = "field")
    public String getId() {
        return id;
    }

    /**
     * @return Returns the primary.
     */
    @PrimaryKeyJoinColumn(name = "primary_id", referencedColumnName = "unique_id")
    @OneToOne(optional = false)
    @AccessType("field")
    public Primary getPrimary() {
        return primary;
    }
}

Answer 1

It most certainly is due to @Id annotation - primary_id is NOT a primary key in this case. Nor can you realistically have @Id and @ManyToOne on the same property.

Let me ask you this - why are you mapping ViewLatestStatusHistoryRow as an entity to begin with? It's not like you ever going to persist it. Consider mapping your latest history entry directly (as read-only) on primary (as many-to-one) and using your view as join table.