Проблема с GridView

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

namespace IT_2
{

    public partial class Date : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            AllTAbleTableAdapters.DateTableAdapter empTA = new AllTAbleTableAdapters.DateTableAdapter();
            GridView2.DataSource = empTA.GetDate();
            GridView2.DataBind();
        }
        protected void Edit_Click(object sender, GridViewEditEventArgs e)
        {
        GridView2.EditIndex = e.NewEditIndex;
        GridView2.DataBind();
        }
        public void Update_Click(object sender, GridViewUpdateEventArgs e)
        {
            //AllTAbleTableAdapters.DateTableAdapter empTA = new AllTAbleTableAdapters.DateTableAdapter();
            //DataTable dt = (DataTable)Session["Date"];

            //GridViewRow row = GridView2.Rows[e.RowIndex];
            //dt.Rows[row.DataItemIndex]["txtID_Date"] = ((TextBox)(row.Cells[1].Controls[0])).Text;
            //dt.Rows[row.DataItemIndex]["txtActual_Date"] = ((TextBox)(row.Cells[2].Controls[0])).Text;
            //dt.Rows[row.DataItemIndex]["txtPlan_Date"] = ((TextBox)(row.Cells[3].Controls[0])).Text;

            TextBox txtID = (TextBox)GridView2.Rows[e.RowIndex].FindControl("txtID_Date");
            TextBox txtAct = (TextBox)GridView2.Rows[e.RowIndex].FindControl("txtActual_Date");
            TextBox txtPlan = (TextBox)GridView2.Rows[e.RowIndex].FindControl("txtPlan_Date");
            AllTAbleTableAdapters.DateTableAdapter empTA = new AllTAbleTableAdapters.DateTableAdapter();
            GridView2.DataSource = empTA.UpdateDate(Convert.ToInt64(txtID.Text), txtAct.Text, txtPlan.Text, Convert.ToInt64(Convert.ToInt64(txtID.Text)));
            //empTA.Connection = conn;
            //empTA.Update( txtID.Text, txtAct.Text,GridView2.DataKeys[e.RowIndex].Values[0].ToString());
            //cmd.Connection = conn;
           // empTA.CommandText = "UPDATE Date.dbo SET ID_Date ='" + txtID.Text + "',Actual_Date ='" + txtAct.Text + "',Plan_Date ='" + txtPlan.Text + "'   WHERE ID_Date='" + GridView2.DataKeys[e.RowIndex].Values[0].ToString() + "'";
           
            GridView2.EditIndex = -1;
            GridView2.DataBind();
        }

        protected void Create_Click (object sender, GridViewCommandEventArgs e)
        {
          if (e.CommandName.Equals("AddNew"))
              {
               AllTAbleTableAdapters.DateTableAdapter empTA = new AllTAbleTableAdapters.DateTableAdapter();
               TextBox txtID=(TextBox)GridView2.FooterRow.FindControl("txtNewID_Date");
               TextBox txtAct = (TextBox)GridView2.FooterRow.FindControl("txtNewActual_Date");
               TextBox txtPlan = (TextBox)GridView2.FooterRow.FindControl("txtNewPlan_Date");
              GridView2.DataSource = empTA.Insert(Convert.ToInt64(txtID.Text), txtAct.Text, txtPlan.Text);
               GridView2.DataBind();
              }
       
        }

GridView2.DataSource = empTA.Insert(Convert.ToInt64(txtID.Text), txtAct.Text, txtPlan.Text);
               GridView2.DataBind();