利用SqlCommand和SqlDataReader对象操作数据库

using System;
 2using System.Data;
 3using System.Configuration;
 4using System.Collections;
 5using System.Web;
 6using System.Web.Security;
 7using System.Web.UI;
 8using System.Web.UI.WebControls;
 9using System.Web.UI.WebControls.WebParts;
10using System.Web.UI.HtmlControls;
11using System.Data.SqlClient; //added by zhangq
12
13public partial class TestDB : System.Web.UI.Page
14{
15    private void ReadSingleResult()
16    {
17        //创建数据连接
18        //从文件web.config中读取数据库链接字符串
19        string conString = ConfigurationManager.ConnectionStrings["DBTESTConnectionString"].ConnectionString;
20        SqlConnection myCon = new SqlConnection(conString);
21
22        //创建执行命令
23        SqlCommand myCmd = new SqlCommand("SELECT TOP 3 * FROM 仓库 ORDER BY 仓库号 DESC", myCon);
24
25        //定义dr
26        SqlDataReader dr = null;
27        try
28        {
29            myCon.Open();     //打开数据库的链接
30            dr = myCmd.ExecuteReader();
31            ShowData(dr);
32            dr.Close();
33        }
34        catch (Exception ex) { Response.Write(ex.Message); }
35        finally
36        {
37            myCon.Close();
38        }
39    }
40    private void ShowData(SqlDataReader dr)
41    {
42        String str = "";
43        for (int i = 0; i < dr.FieldCount; i++)
44        {
45            str = str + dr.GetName(i);
46        }
47        str = str + "<br>";
48        while (dr.Read())
49        {
50            for (int i = 0; i < dr.FieldCount; i++)
51            {
52                str = str + dr[i].ToString();
53            }
54        }
55        Response.Write(str);
56    }
57    protected void Page_Load(object sender, EventArgs e)
58    {
59        ReadSingleResult();
60    }
61}