帝国cms二级栏目亮尚的php代码

不懂的地方具体参考这篇文章：帝国cms用sql批量替换内容字段值
<?php
if($class_r[$GLOBALS[navclassid]][bclassid]==0){
$classid=$GLOBALS['navclassid'];
}else{
$classid=$class_r[$GLOBALS[navclassid]][bclassid];
}
$sql=$empire->query("select classid,sonclass,classname,islast,islist from {$dbtbpre}enewsclass where bclassid=$classid and showclass=0 order by myorder,myorder asc");
while($s=$empire->fetch($sql)){
$classurl=sys_ReturnBqClassname($s,9); 
$tclass="";
if($GLOBALS['navclassid']==$s[classid]){
$tclass='cc';
}
echo '<dd class="'.$tclass.'" ><a href="'.$classurl.'">'.$s[classname].'</a></dd>';
}
?>