SqlConnection,SqlCommand,SqldataReader的用法总结

SqlConnection,SqlCommand,SqldataReader的用法总结:

希望对新手有所帮助!!!

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种形式等价,如果你的数据库是Windows连接方法,直接把连接字符串改成"server=.;database=northwind;integrated security=true;"
        //如果你的数据库是某个实例名,直接把"server=."改成"server=你的计算机名实例名"就可以了

        SqlConnection con = new SqlConnection();
        con.ConnectionString = "server=.;database=northwind;uid=sa;pwd=;";  //双引号中的最后一个分号可以去掉
        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=;";   //双引号中的最后一个分号可以去掉
        //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();

        ////我最经常用这一种,同时连接对象是整个程序的公共对象,所以我一般会把数据库连接封装到一个类中,这样就可以在程序的任何地方随时调用
        //SqlConnection con = new SqlConnection("server=.;database=northwind;uid=sa;pwd=;"); //双引号中的最后一个分号可以去掉
        //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=;";   //双引号中的最后一个分号可以去掉
        //con.Open();
        //SqlCommand cmd = new SqlCommand();
        //cmd.Connection = con;
        //cmd.CommandText = "select * from customers";
        //cmd.CommandType = CommandType.Text;  //这条语句是多余的,因为默认就是Text 
        //SqlDataReader sdr = cmd.ExecuteReader();
        //this.GridView1.DataSource = sdr;
        //this.GridView1.DataBind();
        //sdr.Close();
        //con.Close();
}