Entity not saving-Need help

[Sharmila Punde]

Dear All,
Please take look at following Entity which compiles fine. Users table exists into schema 'app'.
I am using glassfish 3.0.1, Eclipse Persistence Services - 2.0.1 as provider, javadb

@Entity
@Table(name="users", schema="app")
public class Users implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @Column(name="user_id")
    protected Integer userId;

    @Column(name="username")
    protected String username;

    @Column(name="password")
    protected String password;

    @Column(name="category")
    protected int category;


    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }
      
    //....get set methods for other fields
   //.... equals and hashcode methods
}

The code in servlet which is compiled -

    @EJB(name="StaTracker")
    private StatelessTracker tracker;

            //piece service method code 
            Users user = new Users();
            user.setUserId(new Integer(id));
            user.setUsername(name);
            user.setPassword(pwd);
            user.setCategory(categoryInt);
            tracker.addUser(user);

The code in tracker bean as-

    @PersistenceContext(unitName="MyProjectEjbPU")
    private EntityManager en;

    public void addUser(Users user) {
        en.persist(user);
    }

When servlet code is executed i get following error

Internal Exception: java.sql.SQLSyntaxErrorException: 'USER_ID' is not a column in table or VTI 'APP.USERS'.
Error Code: -1
Call: INSERT INTO app.users (user_id, username, category, password) VALUES (?, ?, ?, ?)
bind => [1, somename, 4, passsomeone]
Query: InsertObjectQuery(examples.entities.User[id=1, somename, passsomeone, 4])

What is problem, why i am getting this exception?

Thanks

[Sharmila Punde]

Dear All,
It is solved, i can save that entity. There were two databases in my machine. One was installed
for NetBeans IDE 6.9.1, another was installed by me in /root/. I changed the port and now connected
to right database.
Thanks.