使dedecms的list标签支持多字段排序

织梦list标签的orderby属性只支持按一个字段排序，如果想多字段排序的话，我对后台的PHP进行了修改，使其可以支持多字段排序，修改如下：

先找到文件arc.listview.class.php 在主目录include文件夹下，找到

 //如果不用默认的sortrank或id排序，使用联合查询（数据量大时非常缓慢）
        if(preg_match('/hot|click|lastpost|title/', $orderby))
        {
            $query = "SELECT arc.*,tp.typedir,tp.typename,tp.isdefault,tp.defaultname,
           tp.namerule,tp.namerule2,tp.ispart,tp.moresite,tp.siteurl,tp.sitepath
           $addField
           FROM `#@__archives` arc
           LEFT JOIN `#@__arctype` tp ON arc.typeid=tp.id
           $addJoin
           WHERE {$this->addSql} $ordersql LIMIT $limitstart,$row";
        }
        //普通情况先从arctiny表查出ID，然后按ID查询（速度非常快）
        else
        {
            $t1 = ExecTime();
            $ids = array();
            $query = "SELECT id FROM `#@__arctiny` arc WHERE {$this->addSql} $ordersql LIMIT $limitstart,$row ";
            $this->dsql->SetQuery($query);
            $this->dsql->Execute();
            while($arr=$this->dsql->GetArray())
            {
                $ids[] = $arr['id'];
            }
            $idstr = join(',',$ids);
            if($idstr=='')
            {
                return '';
            }
            else
            {
                $query = "SELECT arc.*,tp.typedir,tp.typename,tp.corank,tp.isdefault,tp.defaultname,
                       tp.namerule,tp.namerule2,tp.ispart,tp.moresite,tp.siteurl,tp.sitepath
                       $addField
                       FROM `#@__archives` arc LEFT JOIN `#@__arctype` tp ON arc.typeid=tp.id
                       $addJoin
                       WHERE arc.id in($idstr) $ordersql ";
            }
            $t2 = ExecTime();
            //echo $t2-$t1;

        }

 替换为

 if($orderby=="default")
        {
            $t1 = ExecTime();
            $ids = array();
            $query = "SELECT id FROM `#@__arctiny` arc WHERE {$this->addSql} $ordersql LIMIT $limitstart,$row ";
            $this->dsql->SetQuery($query);
            $this->dsql->Execute();
            while($arr=$this->dsql->GetArray())
            {
                $ids[] = $arr['id'];
            }
            $idstr = join(',',$ids);
            if($idstr=='')
            {
                return '';
            }
            else
            {
                $query = "SELECT arc.*,tp.typedir,tp.typename,tp.corank,tp.isdefault,tp.defaultname,
                       tp.namerule,tp.namerule2,tp.ispart,tp.moresite,tp.siteurl,tp.sitepath
                       $addField
                       FROM `#@__archives` arc LEFT JOIN `#@__arctype` tp ON arc.typeid=tp.id
                       $addJoin
                       WHERE arc.id in($idstr) $ordersql ";
            }
            $t2 = ExecTime();
            //echo $t2-$t1;

        }
         else
        {
            $query = "SELECT arc.*,tp.typedir,tp.typename,tp.isdefault,tp.defaultname,
           tp.namerule,tp.namerule2,tp.ispart,tp.moresite,tp.siteurl,tp.sitepath
           $addField
           FROM `#@__archives` arc
           LEFT JOIN `#@__arctype` tp ON arc.typeid=tp.id
           $addJoin
           WHERE {$this->addSql} $ordersql LIMIT $limitstart,$row";
        }

 找到

else {
            $ordersql=" ORDER BY arc.sortrank $orderWay";
        }

 替换为

else if($orderby=="default"){
            $ordersql=" ORDER BY arc.sortrank $orderWay";
        }
        else{
           $ordersql=" ORDER BY ".$orderby.",arc.sortrank $orderWay";
        }

 现在在模板中就可以应用了多字段排序了，

模板应用如下：

{dede:list pagesize='17' orderby='arc.title desc,arc.id'}