I have an entity, say Customer, that comes in a library and I cannot change. I would like to add a NamedQuery to this entity using annotation. My first trial is to subclass the entity class and add a NamedQuery to the annotation of the subclass, but that does not work because hibernate requires a discriminator column in the table. I later find a solution by not using subclass, but just to map a separate entity to the table, like this:

@Entity
@Table(name = "CUSTOMER")
@NamedQueries({
@NamedQuery(name = "MY_CUSTOMER_QUERY" ,
query = "SELECT name from Customer " +
"WHERE id in (:ids) order by name")
})
public class MyCustomer {

@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator =
"CUSTOMER_SEQ")
@SequenceGenerator(name = "CUSTOMER_SEQ", sequenceName = "CUSTOMER_SEQ",
allocationSize = 1)
@Column(name = "CUSTOMER_ID")
private Long id;
}

While this appears to work, it does requires specifying a table and an id for the code to work, which is not really used. I wonder if there is a simpler way to do this?