以下是我在visual studio 2005上写的一个类(连的是SQL Server 2005)，已经过测试通过。里面有3个方法比较典型，源码如下:

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;

namespace DatabaseOperate
{
　class SqlOperateInfo
　{
　　//Suppose your ServerName is "aa",DatabaseName is "bb",UserName is "cc", Password is "dd"
　　private string sqlConnectionCommand = "Data Source=aa;Initial Catalog=bb;User ID=cc;Pwd=dd";
　　//This table contains two columns:KeywordID int not null,KeywordName varchar(100) not null
　　private string dataTableName = "Basic_Keyword_Test";

　　private string storedProcedureName = "Sp_InertToBasic_Keyword_Test";
　　private string sqlSelectCommand = "Select KeywordID, KeywordName From Basic_Keyword_Test";
　　//sqlUpdateCommand could contain "insert" , "delete" , "update" operate
　　private string sqlUpdateCommand = "Delete From Basic_Keyword_Test Where KeywordID = 1";
//方法一
　　public void UseSqlReader()
　　{
　　　SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
　　　SqlCommand sqlCommand = new SqlCommand();
　　　sqlCommand.CommandType = System.Data.CommandType.Text;
　　　sqlCommand.Connection = sqlConnection;
　　　sqlCommand.CommandText = sqlSelectCommand;

　　　sqlConnection.Open();
　　　SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
　　　while(sqlDataReader.Read())
　　　{
　　　　//Get KeywordID and KeywordName , You can do anything you like. Here I just output them.
　　　　int keywordid = (int)sqlDataReader[0];
　　　　//the same as: int keywordid = (int)sqlDataReader["KeywordID"]
　　　　string keywordName = (string)sqlDataReader[1];
　　　　//the same as: string keywordName = (int)sqlDataReader["KeywordName"]
　　　　Console.WriteLine("KeywordID = " + keywordid + " , KeywordName = " + keywordName);
　　　}

　　　sqlDataReader.Close();
　　　sqlCommand.Dispose();
　　　sqlConnection.Close();
　　}

//方法二
　　public void UseSqlStoredProcedure()
　　{
　　　SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
　　　SqlCommand sqlCommand = new SqlCommand();
　　　sqlCommand.CommandType = CommandType.StoredProcedure;
　　　sqlCommand.Connection = sqlConnection;
　　　sqlCommand.CommandText = storedProcedureName;

　　　sqlConnection.Open();
　　　sqlCommand.ExecuteNonQuery();
　　　//you can use reader here,too.as long as you modify the sp and let it like select * from ....

　　　sqlCommand.Dispose();
　　　sqlConnection.Close();
　　}
//方法三
　　public void UseSqlDataSet()
　　{
　　　SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
　　　SqlCommand sqlCommand = new SqlCommand();
　　　sqlCommand.CommandType = System.Data.CommandType.Text;
　　　sqlCommand.Connection = sqlConnection;
　　　sqlCommand.CommandText = sqlSelectCommand;

　　　sqlConnection.Open();
　　　SqlDataAdapter sqlDataAdapter = new SqlDataAdapter();
　　　sqlDataAdapter.SelectCommand = sqlCommand;
　　　DataSet dataSet = new DataSet();
　　　//sqlCommandBuilder is for update the dataset to database
　　　SqlCommandBuilder sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);
　　　sqlDataAdapter.Fill(dataSet, dataTableName);

　　　//Do something to dataset then you can update it to 　Database.Here I just add a row
　　　DataRow row = dataSet.Tables[0].NewRow();
　　　row[0] = 10000;
　　　row[1] = "new row";
　　　dataSet.Tables[0].Rows.Add(row);

　　　sqlDataAdapter.Update(dataSet, dataTableName);

　　　sqlCommand.Dispose();
　　　sqlDataAdapter.Dispose();
　　　sqlConnection.Close();
　　}
　}
}