Oracle+.NET+ASP

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.OracleClient;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void TextBox1_TextChanged(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        OracleConnection con = new OracleConnection();
        con.ConnectionString = "Data Source=XE; User ID=system;Password=123456;Unicode=True";
        OracleCommand cmd = new OracleCommand();
        cmd.Connection = con;
        cmd.CommandText = "INSERT INTO pro VALUES(:atrib1,:atrib2)";
        cmd.Parameters.Add(":atrib1", OracleType.VarChar, 30).Value = TextBox1.Text;
        cmd.Parameters.Add(":atrib2", OracleType.VarChar, 30).Value = TextBox2.Text;
        int result = 0;
        con.Open();
        result = cmd.ExecuteNonQuery();
        con.Close();
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        OracleConnection con = new OracleConnection();
        con.ConnectionString = "Data Source=XE;User ID=system;Password=123456;Unicode=True";
        OracleCommand cmd = new OracleCommand();
        cmd.Connection = con;
        cmd.CommandText = "UPDATE pro SET atrib1=:atrib1";
        cmd.Parameters.AddWithValue(":atrib1", TextBox1.Text);
        int result = 0;
        con.Open();
        result = cmd.ExecuteNonQuery();
        con.Close();
    }
    protected void Button3_Click(object sender, EventArgs e)
    {
        OracleConnection con = new OracleConnection();
        con.ConnectionString = "Data Source=XE;User ID=system;Password=123456;Unicode=True";
        OracleCommand cmd = new OracleCommand();
        cmd.Connection = con;
        cmd.CommandText = "delete from pro where codigo=:atrib1";
        cmd.Parameters.AddWithValue(":atrib1", TextBox2.Text);
        int result = 0;
        con.Open();
        result = cmd.ExecuteNonQuery();
        con.Close();
    }
    protected void Button4_Click(object sender, EventArgs e)
    {
        OracleConnection con = new OracleConnection();
        con.ConnectionString = "Data Source=XE;User ID=system;Password=123456;Unicode=True";
        OracleCommand cmd = new OracleCommand();
        cmd.Connection = con;
        OracleDataAdapter cSeleccion = new OracleDataAdapter("select * from pro", con);
        DataSet ds = new DataSet();
        cSeleccion.Fill(ds);
        GridView1.DataSource = ds;
        GridView1.DataBind();
    }
}