My Update function not working. please help me to solve this. no any error message show.

CREATE TABLE [dbo].[dly_prm_dta2] (
    [Flw_mtr]    VARCHAR (100)   NOT NULL,
    [param_dt]   DATE            NOT NULL,
    [param_dept] VARCHAR (50)    NOT NULL,
    [rd_one]     NUMERIC (12, 2) NOT NULL,
    [rd_two]     NUMERIC (12)    NOT NULL,
    [diff]       NUMERIC (12)    NOT NULL,
    [rmk]        VARCHAR (500)   NOT NULL,
    [entry_by]   VARCHAR (50)    NOT NULL,
    [entry_dt]   DATE            NOT NULL,
    [is_updated] VARCHAR (3)     DEFAULT ('No') NULL,
    CONSTRAINT [PK_dly_prm_dta1] PRIMARY KEY CLUSTERED ([Flw_mtr] ASC, [param_dt] ASC)
);

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;

namespace ceo_dshbrd
{
    public partial class home : System.Web.UI.Page
    {
        SqlConnection conn = new SqlConnection(@"Data Source=10.1.246.4;Initial Catalog=ceodshbod;User ID=dba_ntpc_meja_intranet;Password=alpha$890;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False");
        protected void Page_Load(object sender, EventArgs e)
        {
            Label3.Text = System.DateTime.Now.ToString("dd-MM-yyyy");
            string encodedDate = Request.QueryString["date"];
            string selectedDate = HttpUtility.UrlDecode(encodedDate);
            lblSelectedDate.Text = selectedDate;

            if (!this.IsPostBack)
            {
                this.BindData();
                if (Session["emp_id"] == null)
                    Response.Redirect("snsout.aspx");
                else
                {
                    String EmplooyeId = Session["emp_id"].ToString();
                    Label1.Text = " " + EmplooyeId + "";
                    String param_dept = Session["param_dept"].ToString();
                    Label2.Text = "" + param_dept + " ";
                    // String dept = Session["dept"].ToString();
                    //Label3.Text = "" + dept + " ";
                }
            }
        }
        protected void BindData()
        {
            using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["constr"].ConnectionString))
            {
                DateTime dt1 = DateTime.ParseExact(lblSelectedDate.Text, "dd-MM-yyyy", null);
                String dt2 = dt1.ToShortDateString();

                //using (SqlCommand cmd = new SqlCommand("SELECT  Flw_mtr, param_dept,rmk,rd_one,rd_two,diff FROM dly_prm_dta1 where param_dept='" + Session["param_dept"] + "'And param_dt= @pdatelblSelectedDate.Text + "'", con))
                String sqlCommandText = "SELECT Flw_mtr, param_dept,rmk,rd_one,rd_two,diff FROM dly_prm_dta2 where param_dept='" + Session["param_dept"] +
                    "'And param_dt= '" + dt2 + "'";

                using (SqlCommand cmd = new SqlCommand(sqlCommandText, con))
                {
                    cmd.CommandType = CommandType.Text;

                    using (SqlDataAdapter sda = new SqlDataAdapter())
                    {
                        string pd = Session["param_dept"].ToString();
                        //DateTime dt1 = DateTime.ParseExact(lblSelectedDate.Text, "MM/dd/yyyy", null);

                        //cmd.Parameters.AddWithValue("@param_dept", Session["param_dept"]);
                        //cmd.Parameters.AddWithValue("@param_dt", DateTime.ParseExact(lblSelectedDate.Text,"dd-MM-yyyy",null));
                        sda.SelectCommand = cmd;
                        con.Open();
                        cmd.ExecuteNonQuery();

                        DataTable dt = new DataTable();
                        sda.Fill(dt);
                        this.GridView1.DataSource = dt;
                        this.GridView1.DataBind();
                    }
                }
            }
        }
        protected void LinkButton1_Click(object sender, EventArgs e)
        {
            Response.Redirect("caldr.aspx");
        }
        protected void Button2_Click(object sender, EventArgs e)
        {

            using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["constr"].ConnectionString))
            conn.Open();
            foreach (GridViewRow row in GridView1.Rows)
            {
                // GridViewRow row = (sender as Button).NamingContainer as GridViewRow;
                string Flw_mtr = (row.FindControl("txtparam_dsc") as Label).Text;
                string param_dept = (row.FindControl("txtdeptt") as Label).Text;
                string rd_one = (row.FindControl("txtrdone") as TextBox).Text;
                string rd_two = (row.FindControl("txtredtw") as TextBox).Text;
                string diff = (row.FindControl("txtdiff") as TextBox).Text;
                string rmk = (row.FindControl("txtparam_rmrk") as TextBox).Text;
                string entry_by = Label1.Text;
                DateTime entry_dt = DateTime.Today;
                // DateTime entry_dt =Label3.Text.ToString());
                DateTime param_dt = DateTime.ParseExact(lblSelectedDate.Text, "dd-MM-yyyy", null);
                Object a;

                string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
                using (SqlConnection con = new SqlConnection(constr))
                {
                    /* Check if data exists. If data exits, then update else insert */
                    using (SqlCommand cmd = new SqlCommand("select count(*) From dly_prm_dta2 where Flw_mtr = @Flw_mtr and  param_dt = @param_dt"))
                    {

                        cmd.Parameters.AddWithValue("@Flw_mtr", Flw_mtr);
                        cmd.Parameters.AddWithValue("@param_dt", param_dt);
                        cmd.Connection = con;
                        con.Open();
                        a = cmd.ExecuteScalar();
                        con.Close();
                    }

                    SqlCommand cmd1;

                    if (a.ToString().Equals("1"))
                    {
                        cmd1 = new SqlCommand("update dly_prm_dta2 set rd_two = @rd_two ,diff = @diff,entry_by = @entry_by, entry_dt = @entry_dt where flw_mtr = @Flw_mtr and param_dt = @param_dt");

                        cmd1.Parameters.AddWithValue("@Flw_mtr", Flw_mtr);
                        cmd1.Parameters.AddWithValue("@rd_one", rd_one);
                        cmd1.Parameters.AddWithValue("@rd_two", rd_two);
                        cmd1.Parameters.AddWithValue("@diff", diff);
                        cmd1.Parameters.AddWithValue("@rmk", rmk);
                        cmd1.Parameters.AddWithValue("@entry_by", entry_by);
                        cmd1.Parameters.AddWithValue("@entry_dt", entry_dt);
                        cmd1.Parameters.AddWithValue("@param_dt", param_dt);

                        cmd1.Connection = con;
                        con.Open();
                        cmd1.ExecuteNonQuery();
                       con.Close();
                    }
                    else
                    {
                    cmd1 = new SqlCommand("update dly_prm_dta2 set rd_one = @rd_two ,diff = rd_two - @rd_two, param_dt=@param_dt,entry_by = @entry_by, entry_dt = @entry_dt where flw_mtr = @Flw_mtr");
                    cmd1.Parameters.AddWithValue("@Flw_mtr", Flw_mtr);
                    cmd1.Parameters.AddWithValue("@rd_two", rd_two);
                    cmd1.Parameters.AddWithValue("@entry_by", entry_by);
                    cmd1.Parameters.AddWithValue("@entry_dt", entry_dt);
                    param_dt = param_dt.AddDays(1);
                    cmd1.Parameters.AddWithValue("@param_dt", param_dt);

                    cmd1.Connection = con;
                    con.Open();
                    cmd1.ExecuteNonQuery();
                    con.Close();
                    }
                }
            }
        }
    }
}