Duplicate keys with hibernate - postgresql

Question

I have a Postgres 9.5.5 table named mytable under schema myschema. It does not have a primary key - we missed adding it when the table was created. This is causing rows with duplicate values in id column of table. The only access points to this table are through the save(), update() and delete() methods of the Hibernate 4.3.10 Final entity class. Nobody is manually updating the database far as I know. What part of the code is sending duplicate id column values to the table? The entity class looks like this -
#Entity
#Table(name = "mytable", schema = "myschema")
public class MyTable implements Serializable {
/** Id. */
#Id
#GeneratedValue(generator = "myschema.mytable_seq", strategy = GenerationType.AUTO)
#SequenceGenerator(name = "myschema.mytable_seq", sequenceName = "myschema.mytable_seq")
#Column(name = "id", unique = true, nullable = false)
private int id;
Below is the sequence definition in postgres -
CREATE SEQUENCE myschema.mytable_seq
INCREMENT 1
MINVALUE 1
MAXVALUE 9223372036854775807
START 765
CACHE 1;
The hibernate code is something like this (sessionFactory is an autowired instance of org.hibernate.SessionFactory -
#Repository
public class HBMyTableDao extends HBAbstractDAO<MyTable> implements MyTableDao {
public void save(MyTable model) {
sessionFactory.getCurrentSession().save(model);
}
public void saveOrUpdate(MyTable model) {
sessionFactory.getCurrentSession().saveOrUpdate(model);
}
public void update(MyTable model) {
sessionFactory.getCurrentSession().update(model);
}
public void delete(MyTable model) {
sessionFactory.getCurrentSession().delete(model);
}
}

Answer 1

Hibernate requires primary key.
see https://docs.jboss.org/hibernate/orm/4.3/manual/en-US/html_single/#mapping-declaration-id
Maybe you can add a autogenerated column to the table