Invalid attempt to call Read when reader is closed. in Rowdatabound event while reading

Question

I want that my Reader result object fetch matchinng id which matches q=with 2 tables and then get result and save it. and then row data bound function match with all grid and if match on any row it Checked checkbox of that row

{

    if (e.Row.RowType == DataControlRowType.DataRow)
    {

        string qry = "SELECT id FROM info INTERSECT SELECT id FROM info2;";
        SqlCommand cmd = new SqlCommand(qry, con);
        con.Close();


        if (con.State == ConnectionState.Closed)
        {
            con.Open();
            //  string result = ((string)cmd.ExecuteScalar());
            int result = ((int)cmd.ExecuteScalar());
            //SqlDataReader dr = cmd.ExecuteReader(); 

            // CheckBox chk = (CheckBox)e.Row.cells[0].FindControl("chkMyCheckBox");
            CheckBox Chbox = (CheckBox)e.Row.Cells[0].FindControl("chb1");
            if (e.Row.Cells[1].Text == result.ToString())
            {

                Chbox.Checked = true;

                e.Row.Cells[1].ForeColor = System.Drawing.Color.Red;
            }
            else if (e.Row.Cells[2].Text == "1")
            {
                e.Row.Cells[1].ForeColor = System.Drawing.Color.Black;
            }
            else
            {
                e.Row.Cells[1].ForeColor = System.Drawing.Color.Green;
            }
        }

}