[eclipselink-users] Binding both foreign object reference and foreign id

[Cody McCain <cmccain@xxxxxxxxxxxx>]

Would someone mind instructing me on how I might go about binding both a foreign object reference and a foreign key to an object using EclipseLink's JPA implementation?

For example, I have the following simple domain objects (most methods and attributes left out to simplify example):

@Entity
@Table(name = "CUSTOMERS")
public class Customer {
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private long id;

        @Column(name = "NAME")
        private String name;

        // getters and setters below
}

@Entity
@Table(name = "JOBS")
Public class Job {
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private long id;

        @Column(name = "DESCRIPTION")
        private String description;

        @ManyToOne(fetch = FetchType.LAZY)
        @JoinColumn(name = "CUSTOMER_ID")
        private Customer customer;


        // ? JPA attribute, should I use @COLUMN?
        private long customerId;

        // getters and setters below
}


I would like to be able to fetch a Job domain object without loading the referenced Customer object (this the lazy load strategy).  However, I would like to have access to the customerId associated in the link (even if it is read-only).  Would I simply add another attribute and map it to the foreign key field storing the customerId?  What happens if both this field and the reference is changed independently and the Job object is persisted (I realize I should write defensive code to prevent this, but what is the best pattern)?

Thanks for the help!

Regards,

Cody McCain
Director of Software Development
Frac Tech Services, Ltd.
(817) 349-4330 (office)
(580) 504-0797 (mobile)

Ops Support: opssupport@xxxxxxxxxxxx, (817) 764-0432



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