在PHP MySQL中跳过转诊系统中的非活动赞助商id

我有一个转介系统的数据库，用户可以赚取佣金，每个级别多达6个级别。但我省略了不活跃的用户，而不是上。我的脚本为每个活动或非活动的用户提供。下面是我的PHP、MySQL代码

   $eredm= mysqli_query($conn,"
SELECT u1.sponsorid AS referral1
     , u2.sponsorid AS referral2
     , u3.sponsorid AS referral3
     , u4.sponsorid AS referral4
     , u5.sponsorid AS referral5
     , u6.sponsorid AS referral6
     , u7.sponsorid AS referral7
  FROM users AS u1 
      JOIN users As u2 
       ON u1.sponsorid = u2.username
      JOIN users As u3 
       ON u2.sponsorid = u3.username 
      JOIN users As u4 
       ON u3.sponsorid = u4.username 
      JOIN users As u5 
       ON u4.sponsorid = u5.username 
      JOIN users As u6 
       ON u5.sponsorid = u6.username 
      JOIN users As u7 
       ON u6.sponsorid = u7.username 
      JOIN users As u8 
       ON u7.sponsorid = u8.username
     WHERE u1.username = '$userid'
 ");
     $rows= mysqli_fetch_array($eredm);

     $referrer1 = $rows['referral1'];
     $referrer2 = $rows['referral2'];
     $referrer3 = $rows['referral3'];
     $referrer4 = $rows['referral4'];
     $referrer5 = $rows['referral5'];
     $referrer6 = $rows['referral6'];
     $referrer7 = $rows['referral7'];

    $refpc[1]=$refpc1; $refpc[2]=$refpc2; $refpc[3]=$refpc3; 
    $refpc[4]=$refpc4; $refpc[5]=$refpc5; 
    $refpc[6]=$refpc6; $refpc[7]=$refpc7;  

    $cref[1]=$referrer1; $cref[2]=$referrer2; $cref[3]=$referrer3; 
    $cref[4]=$referrer4; $cref[5]=$referrer5; 
    $cref[6]=$referrer6; $cref[7]=$referrer7;  

    $i=1;
    while($i<=$rlevels){

     if (!($cref[$i]=='_')){
     $curcomission = ($invest_to_add/100)*$refpc[$i];
     $curref = $cref[$i];
     $eredm = mysqli_query($conn,"UPDATE users SET 
     earned=earned+$curcomission 
      WHERE username='$curref'");
     $ma = date("Y-m-d");
     $eredm = mysqli_query($conn,"INSERT INTO 
     credits(s_date,s_reason,s_amount,s_user,s_type) VALUES('$ma','Ref. 
     comission from $userid',$curcomission,'$curref',1)") or 
     die(mysqli_error());
      }
     $i++
     }

$eredm=mysqli\u查询（$conn，”
选择u1.sponsorid作为参考1
，u2.作为参考的赞助商2
，u3.作为参考的赞助商3
，u4.作为参考的赞助商
，u5.作为参考的赞助商
，u6.作为参考的赞助商
，u7.作为参考的赞助商
来自用户的u1
以u2身份加入用户
在u1.sponsorid=u2.username上
以u3身份加入用户
在u2.sponsorid=u3.username上
以u4身份加入用户
在u3.sponsorid=u4.username上
以u5身份加入用户
在u4.sponsorid=u5.username上
以u6身份加入用户
在u5.sponsorid=u6.username上
以u7身份加入用户
在u6.sponsorid=u7.username上
以u8身份加入用户
在u7.sponsorid=u8.username上
其中u1.username='$userid'
");
$rows=mysqli_fetch_数组（$eredm）；
$referer1=$rows['referer1']；
$referer2=$rows['referer2']；
$referer3=$rows['referer3']；
$referer4=$rows['referer4']；
$referer5=$rows['referer5']；
$referer6=$rows['referer6']；
$referer7=$rows['referer7']；
$refpc[1]=$refpc1$refpc[2]＝$refpc2$refpc[3]＝$refpc3；
$refpc[4]=$refpc4$refpc[5]＝$refpc5；
$refpc[6]=$refpc6$refpc[7]＝$refpc7；
$cref[1]=$referer1$cref[2]＝$referer2$cref[3]＝$referer3；
$cref[4]＝$referer4$cref[5]＝$referer5；
$cref[6]＝$referer6$cref[7]＝$referer7；
$i=1；
尽管如此，这个API的美妙之处在于它提供了对prepared语句的使用。这里的任何人都可以帮助我