Question

I’m having problems making @Column(name=”example”) working.

I’ve got a User class:

@Entity
public class User {
     @Id
     private String username;
     ....
}

A Role one:

   @Entity
    public class Role {
         @Id
         private String name;
         ....

}

That are in a ManyToMany relationship. So I created a RoleMembership:

@Entity
@IdClass(UserRolePK.class)
public class RoleMembership {

    @Id
    @ManyToOne
    @PrimaryKeyJoinColumn(name="USERNAME")
    private User user;

    @Id
    @ManyToOne
    @PrimaryKeyJoinColumn(name="ROLE")
    private Role role;
....
}

As you can see, the primary key is defined in UserRolePK:

public class UserRolePK{

    @Id
    @Column(name="ROLE")
    private String role;

    @Id
    @Column(name="USERNAME")
    private String user;
...
}

In this class I use @Column(name=”USERNAME”) and @Column(name=”ROLE”) to force its name to that string, but it’s not working: JPA gives it the default names USER_USERNAME and ROLE_NAME (that are in TABLE_ID format).
Can anyone help me finding the mistake?
Thanks,
Andrea

EDIT:
I need to have three tables:

• user (username (pk), password ….)
• user_role (username, role_name)
• role (name (pk), description)

I cannot change User definition in my model.

Answer 1

Remove all the annotations in UserRolePK and change your @PrimaryKeyJoinColumn annotations to @JoinColumn annotations.