@Entity
@Table(name = "order_header")
public class Order extends PersistentObject {
    private int version;
    private String name;
    private Set<OrderLine> orders;

    @Version
    public int getVersion() { return version;  }

    public void setVersion(int version) { this.version = version; }

    public String getName() { return name; }

    public void setName(String name) { this.name = name; }

    @OneToMany(cascade=CascadeType.ALL, mappedBy = "order")
    public Set<OrderLine> getOrders() { return orders; }

    public void setOrders(Set<OrderLine> orders) { this.orders = orders; }
}

@Entity
@Table(name = "order_line")
public class OrderLine extends PersistentObject {
    private int quantity;
    private String description;
    private Order order;

    public int getQuantity() { return quantity; }

    public void setQuantity(int quantity) { this.quantity = quantity; }

    public String getDescription() { return description; }

    public void setDescription(String description) { this.description = description; }

    @ManyToOne
    public Order getOrder() { return order; }

    public void setOrder(Order order) { this.order = order; }
}

Hibernate: select order0_.id as id2_1_, order0_.name as name2_1_, order0_.version as version2_1_, orders1_.order_id as order4_3_, orders1_.id as id3_, orders1_.id as id0_0_, orders1_.order_id as order4_0_0_, orders1_.quantity as quantity0_0_, orders1_.description as descript3_0_0_ from order_header order0_ left outer join order_line orders1_ on order0_.id=orders1_.order_id where order0_.id=?
Hibernate: update order_header set name=?, version=? where id=? and version=?