Insert one-to-many relation using hibernate [closed]

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What is the best way to insert data using Hibernate? As a example when I wont to insert new Order into order table. It has one-to-many relationship with Item. when we consider it on Object manner Order object has Item collection. Should I need to populate all variables(itemName,ItemId,ItemSize,, ) in Item object collection ? If you can please give me the code sample on insert Order using hibernate session..

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@Entity
@Table(name="orders")
class Order {
@Id @GeneratedId private Long id;
@OneToMany(mappedBy="order")
private List<Item> items;

public Order() {
items = new ArrayList<Item>();
}

public void addItem(Item item) {
if (item != null)
items.add(item);
}
    /* getters setters */

}

and item:

@Entity
@Table(name="items")
class Item {
@Id @GeneratedId private Long id;
@ManyToOne
private Order order;
/* getters setters */
}

to query:

Query query = query.createQuery("from Order o where o.id=:id");
query.setLong("id", 1234L);
List<Order> orders = query.list();

to insert could like this:

Session session = null;

    try {
       session = HibernateUtils.getSessionFactory().getCurrentSession();
       Transaction tx = session.beginTransaction();

       Order order = new Order();
       Item item = new Item();
       item.setQuantity(1);
       /* etc.. */
       order.addItem(item);
       item.setOrder(order);
       session.save(item);
       session.save(order);
       tx.commit();
    } finally {
       if (session.isOpen())
           session.close();
    }

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Normally you should create your Item object and set the reference to the Order, since in the general case the Item is the owning side of the relation (assuming a birectional association and that you don't want to use a mapping table).

Besides that, can you give more information on what you have already (especially your Order and Item entities) or where exactly your problem is?