哪位朋友帮我解释一下这段代码啊，越详细越好，谢谢了！！！

Question

public partial class forumindex : FunctionBase //继承
{ 
    protected void Page_Load(object sender, EventArgs e) //页面加载事件触发
    {         Page.Title = "交流园地"; //页面标题
        newscontent.InnerHtml = ShowTopNews(); //新闻内容的HTML加载,要看后一个返回的是什么        string sql = "select forum.type,count(forum.forumid) as total,forumtype.title as typename,forumtype.forummanage,forumtype.description from forum " //查询数据库语句
                        + "left join forumtype on forumtype.id=forum.type " 
                        + "group by forum.type,forumtype.title,forumtype.forummanage,forumtype.description"; 
        DataSet ds = SQLBASE.FillDataSet(sql); //返回ds,一个表的集合,这里应该只是一个表
//接下来从数据库里面取出帖子的数据
        //StringBuilder strHtmlCode = new StringBuilder(1000); 
        for (int i = 0; i < ds.Tables[0].Rows.Count; i++) 
        { 
            DataRow row = ds.Tables[0].Rows[i]; 
            /*---------------该类别的情况-总跟帖数-----------------------------------*/ 
            string enlist_sql = "select count(enlistforum.id) as num from enlistforum " 
                                + "left join forum on enlistforum.forumid=forum.forumid " 
                                + "group by forum.type having forum.type=" + row["type"]; 
            DataSet enlistds = SQLBASE.FillDataSet(enlist_sql); 
            int enlist_num = 0;//该类型帖子的总跟贴数 
            if (enlistds.Tables[0].Rows.Count>0) 
            { 
                DataRow enlistrow = enlistds.Tables[0].Rows[0]; 
                enlist_num = (int)enlistrow["num"]; 
            } 
            /*-------------------今日总发帖数------------------------------------------------*/ 
            string today_sql = "select count(forumid) as todaynum from forum where DATEDIFF(day, createdate, getdate())=0 and type=" + row["type"]; 
            DataSet todayds = SQLBASE.FillDataSet(today_sql); 
            int today_num = 0;//该类型帖子的总跟贴数 
            if (todayds.Tables[0].Rows.Count > 0) 
            { 
                DataRow todayrow = todayds.Tables[0].Rows[0]; 
                today_num = (int)todayrow["todaynum"]; 
            } 
            /*----------------------该项的最后发帖人----------------------------------------*/ 
            string last_sql = "select  top 1 forum.forumid,reguser.username,forum.createdate from reguser,forum where reguser.rid=forum.initiator order by forum.forumid desc"; 
            DataSet lastds = SQLBASE.FillDataSet(last_sql); 
            string lastname = "无记录"; 
            string lastdate = ""; 
            if (lastds.Tables[0].Rows.Count > 0) 
            { 
                DataRow lastrow = lastds.Tables[0].Rows[0]; 
                lastname = lastrow["username"].ToString(); 
                lastdate = lastrow["createdate"].ToString(); 
            } 
            forumlist.InnerHtml += " <br /> <table  style='width: 800px; border: solid 1px #0096FF;background-color:#D6E0EF' cellpadding='1' cellspacing='1'>" 
                        +" <tr>" 
                            + " <td style='width: 100%; height:25px; background-color:#00b0ff' align='left' valign='middle' colspan='7'>" 
                                + " <span style='padding-left:5px; color:White'> <strong> <a href='/code/forumlist.aspx?type=" + row["type"] + "' target='_blank'>" + row["typename"] + " </a> </strong> </span>" 
                            +" </td>" 
                        +" </tr>" 
                        + " <tr bgcolor='#EFEFEF'>" 
                            + " <td style='width: 6%; height:20px;' align='center' valign='middle'>" 
                            + " </td>" 
                            + " <td style='width: 44%; height:20px;' align='center' valign='middle'>论坛" 
                            + " </td>" 
                            + " <td style='width: 6%; height:20px;' align='center' valign='middle'>主题" 
                            + " </td>" 
                            + " <td style='width: 6%; height:20px;' align='center' valign='middle'>贴数" 
                            + " </td>" 
                            + " <td style='width: 6%; height:20px;' align='center' valign='middle'>今日" 
                            + " </td>" 
                            + " <td style='width: 20%; height:20px;' align='center' valign='middle'>最后发表" 
                            + " </td>" 
                            + " <td style='width: 12%; height:20px;' align='center' valign='middle'>版主" 
                            + " </td>" 
                        + " </tr>" 
                        + " <tr>" 
                            + " <td style='width: 6%; height:30px;background-color:#F8F8F8' align='center' valign='middle'>" 
                            +" </td>" 
                            + " <td style='width: 44%; height:30px;background-color:#ffffff' align='left' valign='middle' onMouseOver=\"this.className='altbg1'\" onMouseOut=\"this.className='altbg2'\">" 
                            + " <a href='/code/forumlist.aspx?type=" + row["type"] + "' target='_blank'>" + row["description"] + " </a>" 
                            + " </td>" 
                            + " <td style='width: 6%; height:30px;background-color:#F8F8F8' align='center' valign='middle'>" + row["total"] 
                            + " </td>" 
                            + " <td style='width: 6%; height:30px;background-color:#ffffff' align='center' valign='middle'>" + enlist_num 
                            + " </td>" 
                            + " <td style='width: 6%; height:20px;background-color:#F8F8F8' align='center' valign='middle' >" + today_num 
                            + " </td>" 
                            + " <td style='width: 20%; height:20px;background-color:#ffffff' align='center' valign='middle'>" + lastdate+" by "+lastname 
                            + " </td>" 
                            + " <td style='width: 12%; height:30px;background-color:#F8F8F8' align='center' valign='middle'>" + row["forummanage"] 
                            + " </td>" 
                        +" </tr>" 
                    +" </table>";         } 
        //forumlist.InnerHtml = strHtmlCode; 
    }