c#事务的使用,示例及注意事项

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

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            string connstr=ConfigurationManager.AppSettings["ConnectionString"].ToString();
            SqlConnection con1 = new SqlConnection(connstr);
            if (con1.State.Equals(ConnectionState.Closed))
            {
                con1.Open();
            }
            string sql1 = "insert into guestbook(title,body) values('事务添加1','事务添加1')";
            SqlCommand cmd1 = new SqlCommand(sql1,con1);

            //事务开始 当使用con1.BeginTransaction()后，那么每一个con1相关联的command命令都应该使用这个事务 因而当我们用cmd2时需要新创建一个con2
            SqlTransaction myTran = con1.BeginTransaction();
            cmd1.Transaction = myTran;

            try
            {
                cmd1.ExecuteNonQuery();

                string sql2 = "insert into guestbook(title,body) values('事务添加2','事务添加2')";
                SqlConnection con2 = new SqlConnection(connstr);
                if (con2.State.Equals(ConnectionState.Closed))
                {
                    con2.Open();
                }
                SqlCommand cmd2 = new SqlCommand(sql2, con2);
                cmd2.ExecuteNonQuery();
                con2.Close();
                myTran.Commit();
                Response.Write("事务执行成功！");
            }
            catch
            {
                myTran.Rollback();
                Response.Write("事务执行失败!");
            }
            finally
            {
                con1.Close();
            }
        }

    }
}