System.invalidoperationexception: 'invalid attempt to read when no data is present.'

See more:

C#

Hello, I'm receiving an error when publishing my code. Please help me identify what the problem may be.

The error is on line 77: Total = Total + sdr.GetDecimal(3);


using System;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web.UI;

public partial class Cart : Page
{
protected void Page_Load(object sender, EventArgs e)
{
var skus = Convert.ToString(Session["DataTable"]).Split(',').ToList();

Session["ItemsInCart"] = skus.Count;

var multiSelect = new SqlCommand();

string cmdString1;

cmdString1 = "Select Manufacture, SKU, Name, Price From Products WHERE SKU = " + Session["CartTable"];

var connection =
new SqlConnection(
"Data Source=Omisbi3.niunt.niu.edu;Initial Catalog= 675_z1626585;User ID=OMIS675FA;Password=Omis.675!");

SqlDataReader sdr;

decimal Total = 0;

//Creating the table

var DT = new DataTable("CartDisplay");

var column1 = new DataColumn("SKU");

column1.DataType = Type.GetType("System.Int32");

var column2 = new DataColumn("Manufacture");

column2.DataType = Type.GetType("System.String");

var column3 = new DataColumn("Name");

column3.DataType = Type.GetType("System.String");

var column4 = new DataColumn("Price");

column4.DataType = Type.GetType("System.Decimal");

DT.Columns.Add(column1);

DT.Columns.Add(column2);

DT.Columns.Add(column3);

DT.Columns.Add(column4);

for (var i = 0; i <= skus.Count - 1; i++)

{
multiSelect.CommandText = "Select SKU, Manufacturer, Name, Price From Products WHERE SKU = @SKUS";
multiSelect.Parameters.Clear();
multiSelect.Parameters.AddWithValue("@skus", skus[i]);

multiSelect.Connection = connection;

multiSelect.Connection.Open();

sdr = multiSelect.ExecuteReader();

while (sdr.Read())
sdr = multiSelect.ExecuteReader();
{
DataRow Row1;

Row1 = DT.NewRow();

Total = Total + sdr.GetDecimal(3);

Row1["SKU"] = sdr.GetInt32(0);

Row1["Manufacturer"] = sdr.GetString(1);

Row1["Name"] = sdr.GetString(2);

Row1["Price"] = sdr.GetDecimal(3);

DT.Rows.Add(Row1);
}

multiSelect.Connection.Close();

lblResults.Text = "Your total is $" + Total;
}

GridView1.DataSource = DT;

GridView1.DataBind();
}
}

What I have tried:

I'm not sure what to do. I really need help ASAP. Thank you.