public static int Delete(PurchaseOrder PO) { foreach (PurchaseOrderItem POI in PO.PurchaseOrderItems) { POI.Delete(); } DBAccess db = new DBAccess(); db.AddInt("ID", PO.ID); int retval = db.ExecuteNonQuery(_SQLDelete); AddLog(Status: "PurchaseOrder", Logtext: string.Format("Delete PurchaseOrder: ID:{0}", PO.ID), Metode: "Delete"); return(retval); }