while 循环问题，在线给分

Question

                            while(true) 
                            {  
                                  if($total>0) 
                                  {  
                                      $sql_select=" select  *  from  ot_balance  where user_id=".$user_id."  and ot_balance>0  order by last desc, hr_datetime asc limit 1"; 
                                      $this->db->query($sql_select,0,-1);           
                                        if($record=$this->db->nextRecord()) 
                                          { 
                                          $ot_balance=$record["ot_balance"];                  
                                           } 
                                       if($ot_balance>=$total) 
                                           {    
                                             $main = array($total,$user_id); 
                                             $sql="update ot_balance set ot_used=ot_used+?, ot_balance=ot_to_used-ot_used-ot_cancelled where user_id=? and ot_balance>0  order by last desc, hr_datetime asc limit 1 "; 
                                             $ret = $this->db->execute($sql,$main);  
                                             $total=0; 
                                           } 
                                 else  
                                  {    
                                          $total=$total-$ot_balance; 
                              
                                  }                                                                                                                                              
                                  } 
                                  
                                  else break; 
                                
                            }    
这就是全部的代码呀。

Answer 1

$total之前没赋值嘛，一开始就不大于0,所以只执行一次

Answer 2

do{
    $sql_select=" select  *  from  ot_balance  where user_id=".$user_id."  and ot_balance>0  order by last desc, hr_datetime asc limit 1";
    $this->db->query($sql_select,0,-1);         
    if($record=$this->db->nextRecord())
    {
       $ot_balance=$record["ot_balance"];                 
    }
    if($ot_balance>=$total)
    {   
       $main = array($total,$user_id);
       $sql="update ot_balance set ot_used=ot_used+?, ot_balance=ot_to_used-ot_used-ot_cancelled where user_id=? and ot_balance>0  order by last desc, hr_datetime asc limit 1 ";
       $ret = $this->db->execute($sql,$main); 
       $total=0;
    }
    else 
    {   
       $total=$total-$ot_balance;
                             
     } 
}while($total)

Answer 3

                             if($ot_balance>=$total) 
                              {    
                                  $main = array($total,$user_id); 
                              $sql="update ot_balance set ot_used=ot_used+?, ot_balance=ot_to_used-ot_used-ot_cancelled where user_id=? and ot_balance>0  order by last desc, hr_datetime asc limit 1 "; 
                              $ret = $this->db->execute($sql,$main);  
                              $total=0; <== 只要执行一次,就把循环条件破坏了
                              } 
 

Answer 4

我已弄好了。
是else 也要写update 语句
谢谢大家。
给分了。。