I have this weird gridview problem in .net, I haven't found what can be the issue so far. 
Here is what is it about:
I have a stored procedure which is consumed by sqldatareader.
Then I do have reader read all the values and display from the stored procedure.
Problem is happening now. When I am entering some specific values for parameters, everything is rendered fine to the screen. For example, I have dates and min/max amount and the gridview is populated correctly. 
When I am including one more parameter, lets say customer email, the reader says that is has rows, but the gridview stays blank:

```
SqlDataReader rdrAdvancedReport = commAdvanced.ExecuteReader();
            while (rdrAdvancedReport.Read())
            {
                gvResults.DataSource = rdrAdvancedReport;
                gvResults.DataBind();
            }
            rdrAdvancedReport.Close();

```

What is more "interesting" is that I have another loop once the gridview loop is done, to give me the total amount for all the orders, and the label is populated correctly.

```
  if (rdrTotal.HasRows)
                {
                    while (rdrTotal.Read())
                    {
                        orderTotalSum = orderTotalSum + Convert.ToDouble(rdrTotal["OrderTotal"]);

```

Any idea guys what can be the issue?

Here is the stored procedure too:

```
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE SearchCust
(
@StartTime datetime = null,
@EndTime datetime = null,
@CustomerEmail nvarchar(255) = null,    
@Username nvarchar(255) = null,
@CustomerName nvarchar(255) = null, 
@MinimumOrderAmount decimal = null, 
@MaximumOrderAmount decimal = null, 
)
 AS
BEGIN
SET NOCOUNT ON

SELECT DISTINCT o.OrderID, o.OrderTotal, o.ShippingCountry, n.Name AS OrderStatus, p.Name AS PaymentStatus FROM Order o
JOIN OrderStatus n ON o.OrderStatusID = n.OrderStatusID
JOIN PaymentStatus p ON o.OrderStatusID = p.PaymentStatusID 
JOIN Customer c ON o.CustomerID = c.CustomerID
JOIN OrderProduct op ON o.OrderID = op.OrderID
JOIN ProductValue pv ON op.ProductVariantID = pv.ProductVariantId
WHERE (o.CreatedOn > @StartTime OR @StartTime IS NULL)
AND (o.CreatedOn < @EndTime OR @EndTime IS NULL)
AND (o.ShippingEmail = @CustomerEmail OR @CustomerEmail IS NULL)    
AND (c.Username = @Username OR @Username IS NULL)
AND (o.BillingFirstName + ' ' + o.BillingLastName = @CustomerName OR @CustomerName IS NULL)
AND (o.ShippingFirstName + ' ' + o.ShippingLastName = @CustomerName OR @CustomerName IS NULL)   
AND (o.OrderTotal > @MinimumOrderAmount or @MinimumOrderAmount IS NULL)
AND (o.OrderTotal < @MaximumOrderAmount OR @MaximumOrderAmount IS NULL) 
ORDER BY o.OrderID
END

```

Thanks in advance