将数据一次性加载到DataSet与逐行从DB内读取的性能比较

        string strConnect = "Data Source=localhost;Initial Catalog=cmsw;Integrated Security=True; Application Name=pgq";
        DataSet dsCode = new DataSet();
        using (SqlConnection sqlConn = new SqlConnection(strConnect))
        {
           sqlConn.Open();
           SqlDataAdapter sda = new SqlDataAdapter("SELECT top 200000 TRANCODE from JobRecord  ", sqlConn);
           sda.Fill(dsCode, "Test");
           sqlConn.Close();
        }

        DateTime dt1 = DateTime.Now;

        foreach (DataRow dr in dsCode.Tables[0].Rows)
        {
           using (SqlConnection sqlConn = new SqlConnection(strConnect))
           {


               string code = dr["TRANCODE"].ToString();
               SqlCommand cmd = new SqlCommand("SELECT *  from JobRecord  WHERE TRANCODE=@TRANCODE ", sqlConn);
               cmd.Parameters.AddWithValue("TRANCODE", code);
               sqlConn.Open();
               SqlDataReader dataRead = cmd.ExecuteReader();
               if (dataRead.Read())
               {
                   Console.WriteLine("One Cycle:{0}",dataRead["TRANCODE"]);
               }
               sqlConn.Close();
           }
        }
        DateTime dt2 = DateTime.Now;
        TimeSpan ts1 = dt2 - dt1;
        Console.Clear();

        Console.WriteLine("Total MilSeconds:{0}", ts1.Milliseconds);

        DataSet dsTest2 = new DataSet();
        using (SqlConnection sqlConn = new SqlConnection(strConnect))
        {
           sqlConn.Open();
           SqlDataAdapter sda = new SqlDataAdapter("SELECT top 200000 * from JobRecord  ", sqlConn);
           sda.Fill(dsTest2, "dsTest2");
           sqlConn.Close();
        }
        int serialNo = 0;
        while (serialNo < 200000)
        {
           Random rand = new Random();
           int index = rand.Next(1, 200000);
           var code = dsTest2.Tables[0].AsEnumerable()
               .Where(r => r.Field<string>("TRANCODE") == dsCode.Tables[0].Rows[index]["TRANCODE"].ToString())
               .Select(r => r.Field<string>("TRANCODE")).ElementAtOrDefault(0);
           Console.WriteLine("Scend Cycle:{0}",code);
           serialNo++;
        }

        DateTime dt3 = DateTime.Now;
        TimeSpan ts2 = dt3 - dt2;
        Console.WriteLine("First Result, TotalSeconds:{0};\r\nSecond Result TotalSeconds:{1}", ts1.TotalSeconds, ts2.TotalSeconds);
        Console.ReadLine();