using (SqlConnection conn = new SqlConnection("server=(local);database=pubs;user id=sa;password=sa;"))
{
    conn.Open();
    //事务开始
    using (SqlTransaction trans = conn.BeginTransaction())
    {
        try
        {
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            cmd.CommandType = CommandType.Text;
            cmd.Transaction = trans;

            //添加
            cmd.CommandText = "Insert INTO test([name],[age]) VALUES('aaa',20)";
            cmd.ExecuteNonQuery();
            cmd.CommandText = "Insert INTO test([name],[age]) VALUES('bbb',21)";
            cmd.ExecuteNonQuery();
            cmd.CommandText = "Insert INTO test([name],[age]) VALUES('ccc',22)";
            cmd.ExecuteNonQuery();

            //throw new Exception("Error");

            //提交事务
            trans.Commit();

            Response.Write("ok");
        }
        catch(Exception ex)
        {
            //回滚事务
            trans.Rollback();
            Response.Write(ex.Message);
        }
    }
    conn.Close();
}