C# OleDbDataReader快速数据读取方式(3种)

查询得到OleDbDataReader后，有三种方式支持数据读取，如下：

//方法一**速度中等OleDbDataReader reader = command.ExecuteReader();while (reader.Read()){  var t1 = reader[0]; }//方法二**速度最慢OleDbDataReader reader = command.ExecuteReader();while (reader.Read()){  var t1 = reader["字段名"]; }//方法三**速度最快OleDbDataReader reader = command.ExecuteReader();while (reader.Read()){  var t1 = reader.GetValue(0); }

关于速度的描述，下面我们来简单验证一下。

有一个数据库，数据库中的表TEST有105945行数据，设计一个循环读取来测试他们的读取速度。

测试源码如下：

static void Main(string[] args)    {      string connstr = string.Format("Provider=Microsoft.Jet.OLEDB.4.0 ;Data Source={0};", "F://2.mdb");      string s1 = "ID";      string s2 = "探测号";      string s3 = "X";      string s4 = "Y";      string s5 = "H";      string sql = string.Format("SELECT {0},{1},{2},{3},{4} FROM 管点表", s1, s2, s3, s4, s5);      TimeSpan time1 = new TimeSpan();      TimeSpan time2 = new TimeSpan();      TimeSpan time3 = new TimeSpan();      int count = 50;      //数据库中查询的表有105945行      for (int i = 0; i < count; i++)      {        using (OleDbConnection conn = new OleDbConnection(connstr))        {          #region          conn.Open();          OleDbCommand command = conn.CreateCommand();          command.CommandText = sql;          OleDbDataReader reader = command.ExecuteReader();          DateTime now = DateTime.Now;          while (reader.Read())          {            var t1 = reader[0]; var t2 = reader[1]; var t3 = reader[2]; var t4 = reader[3]; var t5 = reader[4];          }          time1 = time1 + (DateTime.Now - now);          #endregion        }      }      for (int i = 0; i < count; i++)      {        using (OleDbConnection conn = new OleDbConnection(connstr))        {          #region          conn.Open();                    OleDbCommand command2 = conn.CreateCommand();          command2.CommandText = sql;          OleDbDataReader reader = command2.ExecuteReader();          DateTime now = DateTime.Now;          while (reader.Read())          {            var t1 = reader[s1]; var t2 = reader[s2]; var t3 = reader[s3]; var t4 = reader[s4]; var t5 = reader[s5];          }          time2 = time2 + (DateTime.Now - now);          #endregion        }      }      for (int i = 0; i < count; i++)      {        using (OleDbConnection conn = new OleDbConnection(connstr))        {          #region          conn.Open();          OleDbCommand command3 = conn.CreateCommand();          command3.CommandText = sql;          OleDbDataReader reader = command3.ExecuteReader();          DateTime now = DateTime.Now;          while (reader.Read())          {            var t1 = reader.GetValue(0); var t2 = reader.GetValue(1); var t3 = reader.GetValue(2); var t4 = reader.GetValue(3); var t5 = reader.GetValue(4);          }          time3 = time3 + (DateTime.Now - now);          #endregion        }      }      Console.WriteLine(string.Format("方法一：/r/n耗时：{0}s", time1.TotalSeconds));      Console.WriteLine(string.Format("方法二：/r/n耗时：{0}s", time2.TotalSeconds));      Console.WriteLine(string.Format("方法三：/r/n耗时：{0}s", time3.TotalSeconds));       Console.ReadKey();    }