Hi I try to do the homework of Lab 4321_jpa_mapping.
I create a class @Entity @Inheritance(strategy=InheritanceType.JOINED) public class Person2 implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; private String name; .. get() .. set(); } @Entity public class Student2 extends Person2 { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int id; private String school; private double grade; ... } @Entity public class Teacher extends Person2 { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int id private String teach; private int year; ... } I want to know if must put @Id @GeneratedValue(strategy = GenerationType.AUTO) In classes Student and Teacher. I try two time, but it doesn't work I have this fault : Component ID j_idt13:id has already been found in the view. How can I fix that? -- To post to this group, send email to javaprogrammingwithpassion@googlegroups.com To unsubscribe from this group, send email to javaprogrammingwithpassion+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/javaprogrammingwithpassion?hl=en