asp.net架构设计解惑

public class Order
{
    private Guid _id;
    private DateTime _creationDate;
    private int _shippingMethod;
    private int _status;
    private List<OrderItems> _orderItems;
    public Guid Id
    {
        get { return _id; }
        set { _id = value; }
    }

    public List<OrderItems> OrderItems
    {
        get { return _orderItems; }
        set { _orderItems = value; }
    }
    // Business Logic
    public void Place()
    {
        // Validate order based on business rules to ensure it is in
        // a good state to add to the database
        // Check for stock availablity on items ordered
        this.Add();
    }
    public void Cancel()
    {
        // Check to ensure this order can be canceled.
        this.Status = Status.Cancelled();
        this.Save();
    }

    public void ProcessOrder()
    {
        // Check to ensure this order can be processed.
        // Validate order based on business rules
        // Udpate the stock levels of products ordered
    }

    // Data Access Methods
    public void Save()
    {
        // Code to persist changes to the database
    }

    public void Add()
    {
        // Code to Add this object to the database
    }

    public void Delete()
    {
        // Code to remove this object from the database
    }

    public static List<Order> FindAll()
    {
        // Code to retrive all Orders from the database
    }
    public static Order FindBy(Guid id)
    {
        // Code to retrive a specific Order from the database
    }
}