/// <summary>
 /// 將新物件加入 invoice EntitySet 的方法已被取代。請考慮改為使用關聯的 ObjectSet&lt;T&gt; 屬性的 .Add 方法。
 /// </summary>
 public void AddToinvoice(invoice invoice)
 {
     base.AddObject("invoice", invoice);
 }
 /// <summary>
 /// 建立新 invoice 物件。
 /// </summary>
 /// <param name="invoice_id">invoice_id 屬性的初始值。</param>
 public static invoice Createinvoice(global::System.Int32 invoice_id)
 {
     invoice invoice = new invoice();
     invoice.invoice_id = invoice_id;
     return invoice;
 }