I cannot retreive the List<subjects> from book. The save and update of a
book when a subject changes its fine, the problem is when retreiving books,
It doeesnt retreive their subjects. I need help. Here;s the code.
@Entity
@Table(name = "book")
public class Book implements Serializable, IsSerializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key id;
private String bookName;
private String comment;
@OneToMany(mappedBy="book",cascade = CascadeType.ALL)
private List<Subject> subjects;
//setters and getters
--------------------------------------------------------------------------------------
@Entity
@Table(name = "subject")
public class Subject implements Serializable, IsSerializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key id;
private String name;
private int visible;
@Basic
private Text content;
@Basic
@ManyToOne
private Book book;
// setters and getters
----------------------------------------------------------------------------------------------------
public List<Book> getBooks() throws GeneralException,
BookNotFoundException, NullParameterException {
entityManager = EMF.get().createEntityManager();
List<Book> list;
try {
String sql = "SELECT b FROM Book b";
list =
entityManager.createQuery(sql).getResultList(); //this list is
retreived with the books but without their subjects
} catch (Exception e) {
throw new GeneralException("Exception in method getBookes: " +
e.getMessage());
} finally {
if (entityManager.isOpen()) {
entityManager.close();
}
}
if (list == null || list.isEmpty()) {
throw new BookNotFoundException("Book not found in method
getBookes");
}
return list;
}
Please, I need some help.
Cheers.
--
Kido.
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