public Guid Create(Guid productId, Guid?userId, string customerName, string customerPhone, double price, byte amount, string address, string comment) { var orderId = Guid.NewGuid(); var re = (int)db.pb_Order_Create( orderId, productId, userId, customerName, customerPhone, price, amount, address, comment).Single(); if (re >= 0) { return(orderId); } else { return(Guid.Empty); } }