Icey Thomas [http://community.jboss.org/people/icey.xiong] created the discussion "static class act as an entity ,EntityNotFoundException happend when delete the last record" To view the discussion, visit: http://community.jboss.org/message/633986#633986 -------------------------------------------------------------- Dear all,      I write an entity like this: @Entity public class Employee {      @Id      private long id;          private String name;           @OneToMany      private Mao<String,EmpDetail> detail=new TreeMap<String,EmpDetail>();        //set ,get functions pass        @Entity      public static class EmpDetail      {               @Id                protected long id;                protected String address;                //set ,get functions pass      } }   I  delete an EmpDetail like this:     em.remove(em.getReference(EmpDetail.class,4)); // em is the entity manager   I delete the record successful but the last one. Exception is here:   javax.persistence.EntityNotFoundException:deleted entity passed to persiste:(...Employee$EmpDetail#<null>) some one knows what is going on?  thank you! -------------------------------------------------------------- Reply to this message by going to Community [http://community.jboss.org/message/633986#633986] Start a new discussion in EJB Development at Community [http://community.jboss.org/choose-container!input.jspa?contentType=1&...]