php打印二维数组问题

$sql="select Sortname,majorname from major left join majorsort on major.Sortid=majorsort.Sortid where mtype='本科'";

$list=mysql_query($sql,$conn) or die (print '错误');


$arr=array();


while($v=mysql_fetch_assoc($list)){
$arr[]=$v; //这里的arr[]还是二维
     }

foreach($arr as $key => $value){

        echo $value['sortname'];//此处单引号里面可以直接取出列名··········

}

//  Array([0]=>array('sortname')=>文理科,'majorname'=>文科;)