如果数据库更新失败，Paypal 回滚/退款 IPN？ [已关闭]

Question

我想知道我应该如何处理客户为数字商品付费的情况，然后调用 IPN 并交付数字商品。如果交付过程中出现问题怎么办？此案应如何处理？在这种情况下我可以取消/退款吗？

我的 IPN 代码基于我找到的示例

protected void Page_Load(object sender, EventArgs e)
{
    //Post back to either sandbox or live
    string strSandbox = "https://www.sandbox.paypal.com/cgi-bin/webscr";
    // string strLive = "https://www.paypal.com/cgi-bin/webscr";
    HttpWebRequest req = (HttpWebRequest)WebRequest.Create(strSandbox);

    //Set values for the request back
    req.Method = "POST";
    req.ContentType = "application/x-www-form-urlencoded";
    byte[] param = Request.BinaryRead(HttpContext.Current.Request.ContentLength);
    string strRequest = Encoding.ASCII.GetString(param);
    strRequest += "&cmd=_notify-validate";
    req.ContentLength = strRequest.Length;

    //for proxy
    //WebProxy proxy = new WebProxy(new Uri("http://url:port#"));
    //req.Proxy = proxy;

    //Send the request to PayPal and get the response
    StreamWriter streamOut = new StreamWriter(req.GetRequestStream(), System.Text.Encoding.ASCII);
    streamOut.Write(strRequest);
    streamOut.Close();
    StreamReader streamIn = new StreamReader(req.GetResponse().GetResponseStream());
    string strResponse = streamIn.ReadToEnd();
    streamIn.Close();

    if (strResponse == "VERIFIED")
    {
        //UPDATE YOUR DATABASE

        //check the payment_status is Completed
        //check that txn_id has not been previously processed
        //check that receiver_email is your Primary PayPal email
        //check that payment_amount/payment_currency are correct
        //process payment
    }
    else if (strResponse == "INVALID")
    {
        //UPDATE YOUR DATABASE
    }
    else
    {  //UPDATE YOUR DATABASE
    }
}

如果我的数据库更新失败怎么办？

Answer 1

首先，我会确保使用干净的 SQL 语句，这样数据库就不会出现错误。如果数据库连接错误，您可以返回 500 响应，PayPal 的 IPN 系统将不断重试，直到收到成功的 200 OK 响应。

如果您确实想根据脚本中的任何失败提交退款，您可以通过 RefundTransaction API 来完成。