PHP如何同时查询多个ID

include 'include/cmsdj.conn.php'; 

$CD_ID=SafeRequest('id','get');

        global $db;

        $sql='Select * from '.tname('dj').' where CD_ID='.$CD_ID.'';

        $row=$db->getrow($sql);

        $server=$db->getrow('select * from '.tname('server').' where CD_ID='.$row['CD_Server'].'');

        if($row){

                $CD_Url=$row['CD_Url'];

                        $playurl=$server['CD_Url'].$CD_Url;

        echo '';}

?>