按重量选择随机值php

看看我的桌子：

userid-lottaryid-amount
1 -------- 1 ----  1
2 -------- 1 ---- 10
3 -------- 1 ---- 15
4 -------- 1 ---- 20

我想选择一个胜利者.另一个人获得第二名.

我无法随机选择获胜者,因为第四位用户有20张门票而第一位用户只有一张.
因此,我需要按重量生成随机结果,以便更公平.

我发现下面的PHP功能,但我无法弄清楚如何使用它.

function weighted_random_simple($values,$weights){ 
      $count = count($values); 
      $i = 0; 
      $n = 0; 
      $num = mt_rand(0,array_sum($weights)); 

      while($i < $count){
          $n += $weights[$i]; 
          if($n >= $num){
              break; 
          }
          $i++; 
      } 
      return $values[$i]; 

  }

    $values = array('1','10','20','100');
    $weights = array(1,10,20,100);

    echo weighted_random_simple($values,$weights);

我必须将userid colomn作为数组提取到$values并将colomn的数量提取到$weights.但我不敢.

到目前为止,这是我的代码：

$query = $handler->prepare("SELECT 

      `cvu`.`lottaryid` as `lottaryid`,`cvu`.`userid` as `userid`,`cvu`.`amount` as `amount`,`members`.`id` as `members_memberid`,`members`.`username` as `username`

      FROM `lottariesandmembers` as `cvu`

      LEFT JOIN `members` as `members` ON `cvu`.`userid` = `members`.`id`  WHERE `cvu`.`lottaryid` = 2");
    $query->bindParam(':lottaryid',$lottaryid,PDO::PARAM_INT);
    $query->execute();



    while($r = $query->fetch()) {

        for ( $count=1 ; $count <= $r["amount"] ; $count++ ) {

            $abcprint = "$r[userid].$count - $r[username] - <br>";

            echo "$abcprint";

        }


    }

这个代码我只列出了用户数量.例如：

1.1 user1
2.1 user2
2.2 user2
2.3 user2
..
2.10 user2
3.1 user3
..
3.15 user3
4.1 user4
..
4.20 user4

等等.但我仍然坚持如何在该名单上挑选一名获胜者.

如果你想帮助我,我想合并这些代码并创建这个小脚本.

如果你在另一方面看到解决方案,我也会开放头脑风暴.