实例:使用数据读取器获取结果集的信息

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Data;using System.Data.SqlClient;namespace ResultSetInfo{    class Program    {        static void Main(string[] args)        {            string connString = @"Data Source=SNH;Initial Catalog=Northwind;Integrated Security=True";            string sql = @"select contactname,contacttitle from customers where contactname like 'M%'";            SqlConnection conn = new SqlConnection(connString);            try            {                conn.Open();                SqlCommand cmd = new SqlCommand(sql, conn);                SqlDataReader rdr = cmd.ExecuteReader();                                //get column names                Console.WriteLine("Column Name:\t{0} {1}", rdr.GetName(0).PadRight(25), rdr.GetName(1));                //get column data types                Console.WriteLine("Data Type:\t{0} {1}", rdr.GetDataTypeName(0).PadRight(25), rdr.GetDataTypeName(1));                Console.WriteLine();                while (rdr.Read())                {                     //get column values for all rows                    Console.WriteLine("\t\t{0} {1}", rdr.GetString(0).ToString().PadRight(25), rdr.GetString(1));                }                //get number of columns                Console.WriteLine();                Console.WriteLine("Number of columns in a row: {0}", rdr.FieldCount);                             // get info about each column                Console.WriteLine("'{0} is as index {1} " + "and its type is: {2}", rdr.GetName(0), rdr.GetOrdinal("contactname"), rdr.GetFieldType(0));                Console.WriteLine("'{0}' is at index {1} " + "and its type is: {2}", rdr.GetName(1), rdr.GetOrdinal("contacttitle"), rdr.GetFieldType(1));                rdr.Close();            }            catch (SqlException e)            {                Console.WriteLine("Error: " + e.ToString());            }            finally             {                conn.Close();            }            Console.ReadKey();        }    }}

示例说明：

GetName方法根据列的索引获取列的名称。rdr.GetName(1)

GetDataTypeName方法返回数据库中的一列的数据类型。rdr.GetDataTypeName(0)

FieldCount属性包含结果集中的列数。在不知道列的名称或其他属性的情况下遍历列时，十分有用。