我这段代码是获取dizcuss帖子的一个函数，帮我看看哪里有问题？function recommend_posts($page){
    global $_G;
    //$expect_fids='1000';//不调用的版块，多个用半角逗号分开
    //if(!$_GET['from'] || $_GET['from']==''){
    //    $from="t.`fid` NOT in ($expect_fids) and";
    //}
    $type = '';
    //首页帖子主列表
    $tnum=35;
    $lasttime = strtotime("-7 month");
    $begin=($page-1)*$tnum;
    $manylist=array();
    $orderby='t.`dateline` desc';
    $sql = "SELECT t.*,p.pid,f.name,i.viewperm,i.extra from ".DB::table("forum_thread")." t LEFT JOIN ".DB::table("forum_post")." p on p.tid=t.tid LEFT JOIN ";
    $sql .= DB::table("forum_forum")." f on f.fid=t.fid LEFT JOIN ".DB::table("forum_forumfield")." i on i.fid=t.fid WHERE t.displayorder>=0 and t.dateline>$lasttime and p.first=1 and f.status=1 $type group by t.tid ORDER BY $orderby LIMIT $begin , $tnum";
    $res = DB::query($sql);

    $usergroup=user_group($_G['uid']);
    $userextgroupids=explode(",",preg_replace("/\s+/", ",", $usergroup["extgroupids"]));
    $allauthids=array();
    while ($rw=DB::fetch($res)) {
        if ($rw['readperm'] && $rw['readperm']>$usergroup['readaccess']){
            //跳过无权限帖子。
            continue;
        }
        $viewperms = trim($rw["viewperm"]);
        $viewperms_a = explode(",",preg_replace("/\s+/", ",", $viewperms));
        
        if ($usergroup['groupid']=="1" || empty($viewperms_a)){
            //all can view.
        }else if (!in_array($usergroup['groupid'],$viewperms_a) && empty(array_intersect($userextgroupids, $viewperms_a))){
            continue;
        }

        $rw['lastposterenc']=urlencode($rw['lastposter']);
        $rw['lastposterid']=DB::result_first("select authorid from ".DB::table("forum_post")." where tid='$rw[tid]' and first=0 ORDER BY pid desc");
        $rw['extra'] = unserialize(stripslashes($rw['extra']));// forumcolor
        //$rw['dateline'] = dgmdate($rw['dateline'], 'u', '9999', getglobal('setting/dateformat')); //$rw['dateline'] = dgmdate($rw['dateline'],'Y-m-d H:i');
        $rw['rushreply'] = getstatus($rw['status'], 3);

        if($rw['highlight']) {
            $colorarray = array('', '#EE1B2E', '#EE5023', '#996600', '#3C9D40', '#2897C5', '#2B65B7', '#8F2A90', '#EC1282');
            $string = sprintf('%02d', $rw['highlight']);
            $stylestr = sprintf('%03b', $string[0]);
            $rw['highlight'] = 'style="';
            $rw['highlight'] .= $stylestr[0] ? 'font-weight: bold;' : '';
            $rw['highlight'] .= $stylestr[1] ? 'font-style: italic;' : '';
            $rw['highlight'] .= $stylestr[2] ? 'text-decoration: underline;' : '';
            $rw['highlight'] .= $string[1] ? 'color: '.$colorarray[$string[1]] : '';
            $rw['highlight'] .= '"';
        } else {
            $rw['highlight'] = '';
        }
        $post = C::t('forum_post')->fetch_threadpost_by_tid_invisible($rw['tid']);
        $rw['message'] = trim(messagecutstr($post['message'], 230));
        $table='forum_attachment_'.substr($rw['tid'], -1);
        $getimage = DB::fetch_first("SELECT aid,attachment FROM ".DB::table($table)." WHERE tid='$rw[tid]' AND readperm=0 AND price=0 AND isimage!=0 ORDER BY `dateline` ASC LIMIT 0,1");
        $rw['image'] = getforumimg($getimage['aid'],0,190,105);
        $manylist[]=$rw;
        $allauthids[]=$rw['authorid'];
    }
    loadcache('stamps');
    return $manylist;


}