Invalid composite primary key specification

[Ashley Bye]

I know this topic has come up in the past, but after looking through previous posts and a lot of "Googling" I am still utterly confused as to why I get the above error. The relevant exception in full is:

Exception Description: Invalid composite primary key specification. The names of the primary key fields or properties in the primary key
class [com.basicdesigns.flyingapp.entities.FlyingClubStaff$FlyingClubStaffID] and those of the entity bean class
[class com.basicdesigns.flyingapp.entities.FlyingClubStaff] must correspond and their types must be the same. Also, ensure that you have
specified ID elements for the corresponding attributes in XML and/or an @Id on the corresponding fields or properties of the entity class.

The relevant sections of my entity classes are shown below.

User.java

@Entity
public class User implements Serializable
{
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "user_id")
    private int id;
    ...
    @OneToMany(mappedBy = "user")
    private List<FlyingClubStaff> staffAtClubs = null;
    ...
}

FlyingClub.java

@Entity
@Table(name = "flying_club")
public class FlyingClub implements Serializable
{
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "flying_club_id")
    private int id;
    ...
    @OneToMany(mappedBy = "flyingClub")
    private List<FlyingClubStaff> staffMembers = null;
    ...
}

FlyingClubStaff.java

@Entity
@Table(name = "flying_club_staff")
@IdClass(FlyingClubStaff.FlyingClubStaffID.class)
public class FlyingClubStaff implements Serializable
{
    private static final long serialVersionUID = 1L;
    @Id
    @Column(name = "flying_club_id")
    private int flyingClubId;
    @Id
    @Column(name = "user_id")
    private int userId;
    ...
    @ManyToOne
    @JoinColumn(name = "flying_club_id", updatable = false, insertable = false, referencedColumnName = "flying_club_id")
    private FlyingClub flyingClub;
    @ManyToOne
    @JoinColumn(name = "user_id", updatable = false, insertable = false, referencedColumnName = "user_id")
    private User user;
    ...
    public class FlyingClubStaffID implements Serializable
    {
        private static final long serialVersionUID = 1L;
        private int flyingClubId;
        private int userId;
        ...
    }
}

Relevant database schema (if needed)

-- -----------------------------------------------------
-- Table `flying_app_db`.`flying_club`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `flying_app_db`.`flying_club` (
  `flying_club_id` INT(11) NOT NULL AUTO_INCREMENT,
  ...
  PRIMARY KEY (`flying_club_id`))
...;

-- -----------------------------------------------------
-- Table `flying_app_db`.`user`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `flying_app_db`.`user` (
  `user_id` INT(11) NOT NULL AUTO_INCREMENT,
  ...
  PRIMARY KEY (`user_id`))
...;

-- -----------------------------------------------------
-- Table `flying_app_db`.`flying_club_staff`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `flying_app_db`.`flying_club_staff` (
  `user_id` INT(11) NOT NULL,
  `flying_club_id` INT(11) NOT NULL,
  ...
  PRIMARY KEY (`user_id`, `flying_club_id`),
  ...
  CONSTRAINT `flying_club_staff_flying_club_FK`
    FOREIGN KEY (`flying_club_id`)
    REFERENCES `flying_app_db`.`flying_club` (`flying_club_id`)
    ...
  CONSTRAINT `flying_club_staff_user_FK`
    FOREIGN KEY (`user_id`)
    REFERENCES `flying_app_db`.`user` (`user_id`)
    ...)
...;

Since I have annotated the fields with @Id in the entity class I have not added any reference to them in persistence.xml.

Any help / pointers in the right direction welcome.

[Janeice DelVecchio]

Where's the class named FlyingClubStaffID?

@IdClass(FlyingClubStaff.FlyingClubStaffID.class)

[Ashley Bye]

It would appear I forgot to post that class. I solved the problem using an embeddable class and an embedded id. I say I solved the problem, I gave up and got NetBeans to solve the problem for me. I'll revisit coding it by hand another time. For now, I've stepped down a notch to a smaller project which doesn't have any composite keys so I can get the hang of things - people don't run before they learn to crawl and walk after all!