SqlConnection,SqlCommand,SqldataReader的用法總結:

SqlConnection,SqlCommand,SqldataReader的用法總結:

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
     {
        //-------------------SqlConnection,SqlCommand,SqldataReader的用法-------------------//

        //下面的4種形式等價,如果你的數據庫是Windows連接方法,直接把連接字符串改成"server=.;database=northwind;integrated security=true;"
        //如果你的數據庫是某個實例名,直接把"server=."改成"server=你的計算機名實例名"就可以了

         SqlConnection con = new SqlConnection();
         con.ConnectionString = "server=.;database=northwind;uid=sa;pwd=;";  //雙引號中的最後一個分號可以去掉
         con.Open();
         SqlCommand cmd = con.CreateCommand();
         cmd.CommandText = "select * from customers";
         SqlDataReader sdr = cmd.ExecuteReader();
        this.GridView1.DataSource = sdr;
        this.GridView1.DataBind();
         sdr.Close();
         con.Close();

        //SqlConnection con = new SqlConnection();
        //con.ConnectionString = "server=.;database=northwind;uid=sa;pwd=;";   //雙引號中的最後一個分號可以去掉
        //con.Open();
        //SqlCommand cmd = new SqlCommand("select * from customers");
        //cmd.Connection = con;
        //SqlDataReader sdr = cmd.ExecuteReader();
        //this.GridView1.DataSource = sdr;
        //this.GridView1.DataBind();
        //sdr.Close();
        //con.Close();


        ////數據連接對象是整個程序的公共對象,所以我一般會把數據庫連接封裝到一個類中,這樣就可以在程序的任何地方隨時調用
        //SqlConnection con = new SqlConnection("server=.;database=northwind;uid=sa;pwd=;"); //雙引號中的最後一個分號可以去掉
        //con.Open();
        //SqlCommand cmd = new SqlCommand("select * from customers", con);
        //SqlDataReader sdr = cmd.ExecuteReader();
        //this.GridView1.DataSource = sdr;
        //this.GridView1.DataBind();
        //sdr.Close();
        //con.Close();

        //SqlConnection con = new SqlConnection();
        //con.ConnectionString = "server=.;database=northwind;uid=sa;pwd=;";   //雙引號中的最後一個分號可以去掉
        //con.Open();
        //SqlCommand cmd = new SqlCommand();
        //cmd.Connection = con;
        //cmd.CommandText = "select * from customers";
        //cmd.CommandType = CommandType.Text;  //這條語句是多餘的,因爲默認就是Text 
        //SqlDataReader sdr = cmd.ExecuteReader();
        //this.GridView1.DataSource = sdr;
        //this.GridView1.DataBind();
        //sdr.Close();
        //con.Close();
}

#c#