PHP编写在线考试题，急需高手指教！谢谢！

现在数据库有了，要用rand乱数随机生成数据库里的试题，还得有採分设置，现在很乱！<?php

    require ('dbconnect.php');// データベース接続:

    if (!empty($_POST)) {
    $yougo = mysql_real_escape_string($_POST['yougo']);
    $query = "SELECT * FROM yougosyu WHERE yougo like '$yougo%'";
    $result = mysql_query($query);

    if (!$result) {
        $message  = 'Invalid query: ' . mysql_error() . "\n";
        $message .= 'Whole query: ' . $query;
        die($message);
    }


// step 1
    $count = 1;
    while ($row = mysql_fetch_assoc($result)) {
         $count++;
    }

//step2
        $ran = mt_rand();
        $bingo = $ran % $count + 1;
        

    $result = mysql_query($query);
    $count = 1;
    while ($row = mysql_fetch_assoc($result)) {
         $count++;
                if ($count == $bingo){
                  echo $count;
            echo ')  ';
            echo $row['yougo'];
            echo '...';
            echo $row['setumei'];

        }
    }

     $ran = mt_rand();
        $pos = $ran % 4 + 1;
        echo $pos;
        
    mysql_free_result($result);
}
?>

<form action="./yougo_query.php"  method="post">
<font size=3>
<dl>
用語検索 <input type="text" name="yougo" />
</dl>
<input type="submit" value="検索" />  
<a href="./index.html">Top Page へ</a>
</form>