如何以循环顺序从数据库表中仅获取3个数据？

Question

我想在任何用户登录时从数据库表中只获取3个数据。之后当下一个用户登录时，下一个3个问题将会到来。我怎样才能做到这一点？我应该在SELECT查询中做出哪些更改？

$sql ="SELECT * FROM questiontypes";
$query = mysql_query($sql);
$qset = "";
while($result = mysql_fetch_array($query)) {
    $qset .='<li id="qtypeli">'.$result['qtname'].'</li>';
    $sql1 = "select questions .* from questions where qtype='".$result['qtname']."'order by RAND() LIMIT 3";
    $query1 = mysql_query($sql1);
    while($result1 = mysql_fetch_array($query1)) {
        $qset .='<li id="'.$result1['qid'].'" qt="'.$result1['qtid'].'"><span class="qnamespan"> '.$i.'. '.$result1['qname'].'</span></li>