todaynews.aspx.cs

一个简单的新闻后台管理系统

using System;
using System.Data;
using System.Configuration;
using System.Collections;
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 TodayNews : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string sqlcon = ConfigurationManager.ConnectionStrings["news_manageConnectionString2"].ConnectionString.ToString();
        SqlConnection con = new SqlConnection(sqlcon);
        DataSet dst = new DataSet();
        con.Open();

        //读出ItemId的数目



        int i = 0, j = 1;
        string sqlitems = "select ItemID,ItemName from t_Item order by itemid desc";
        SqlCommand com = new SqlCommand(sqlitems, con);
        SqlDataReader reader = com.ExecuteReader();

        if (reader.Read())
        {
            //用i接收ItemId 的值



            i = (int)reader.GetValue(0);
            con.Close();
        }
        //
        string sqlUnion = "";
        for (; i >= 1; i--)
        {
            sqlUnion = sqlUnion + "union select top 5 t_News.newsid, t_News.newsdate, t_News.newstitle, t_Class.ItemID  from t_Class, t_News where t_News.ClassID = t_Class.ClassID and itemid = " + j + " ";
            j++;
        }
        con.Open();

        //把t_item表填充到数据
        string sqlItem = "select ItemID, ItemName from t_Item";
        SqlDataAdapter sdaItems = new SqlDataAdapter(sqlItem, con);
        sdaItems.Fill(dst, "t_Item");

        //把新闻表填充到数据源
        string sqlNews = "select top 5 t_News.newsid, t_News.newsdate, t_News.newstitle, t_Class.ItemID from t_Class, t_News where t_News.ClassID = t_Class.ClassID and itemid = 1" + sqlUnion + " order by newsdate desc";
        SqlDataAdapter sdaNews = new SqlDataAdapter(sqlNews, con);
        sdaNews.Fill(dst, "t_News");

        //datalist嵌套表使用，建立关系通过ItemID,使外层datalist访问里层
        dst.Relations.Add("myrelation", dst.Tables["t_Item"].Columns["ItemID"], dst.Tables["t_News"].Columns["ItemID"]);
        dlstItem.DataSource = dst.Tables["t_Item"].DefaultView;
        dlstItem.DataBind();
        con.Close();
    }
    protected void dlstItem_SelectedIndexChanged(object sender, EventArgs e)
    {

    }
}