insert,update,delete without using store procedure

using System;
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;



public partial class _Default : System.Web.UI.Page
{
    SqlDataAdapter da;
    DataTable dt;
    DataSet ds;

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            GridView();

        }
    }

    private void GridView()
    {
        da = new SqlDataAdapter("select * from test", "Data Source=SPADEWRO-47A76C;Initial Catalog=test;Integrated Security=True");
        dt = new DataTable();
        da.Fill(dt);
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }

    protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        string str;
        str = GridView1.Rows[e.RowIndex].Cells[2].Text;
        SqlDataAdapter daa = new SqlDataAdapter("delete from test where No=" + str + " ", "Data Source=SPADEWRO-47A76C;Initial Catalog=test;Integrated Security=True");
        ds = new DataSet();
        daa.Fill(ds);
        GridView1.EditIndex = -1;
        GridView();
    }
    protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
    {



        GridView1.EditIndex = e.NewEditIndex;
        GridView();
    }
    protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
    {
        GridView1.EditIndex = -1;
        GridView();
    }
    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {

        SqlDataAdapter daa ;
        DataSet dss ;
        TextBox t1, t2;
        t1 = ((TextBox)GridView1.Rows[e.RowIndex].Cells[2].Controls[0]);
        t2 = ((TextBox)GridView1.Rows[e.RowIndex].Cells[3].Controls[0]);
      
        if(((LinkButton)GridView1.Rows[0].Cells[0].Controls[0]).Text == "Insert")
        {
          daa = new SqlDataAdapter("insert into test values("+t1.Text+", '"+t2.Text+"')", "Data Source=SPADEWRO-47A76C;Initial Catalog=test;Integrated Security=True");
         dss = new DataSet();
        daa.Fill(dss);
        GridView1.EditIndex = -1;
    }
        else
        {
         daa = new SqlDataAdapter("update test set name='" + t2.Text + "' where No=" + t1.Text + " ", "Data Source=SPADEWRO-47A76C;Initial Catalog=test;Integrated Security=True");
        dss = new DataSet();
        daa.Fill(dss);
         
    }
        GridView1.EditIndex = -1;
        GridView();
}
  
    protected void Button1_Click(object sender, EventArgs e)
    {
        SqlDataAdapter daa = new SqlDataAdapter("select * from test", "Data Source=SPADEWRO-47A76C;Initial Catalog=test;Integrated Security=True");
        DataTable dtt = new DataTable ();
        daa.Fill(dtt);

        DataRow dr = dtt.NewRow();
        dtt.Rows.InsertAt(dr, 0);
        GridView1.EditIndex = 0;
        GridView1.DataSource = dtt;
        GridView1.DataBind();
        ((LinkButton)GridView1.Rows[0].Cells[0].Controls[0]).Text = "Insert";
    }
}