PHP：MySQL查询无故重复更新

下面的代码首先是客户端代码，然后是类文件。PHP：MySQL查询无故重复更新

由于某些原因，'deductTokens（）'方法调用了两次，因此对帐户收取了双倍的费用。我一直在编程通宵，所以我可能只需要第二双眼睛：

if ($action == 'place_order') { 

    if ($_REQUEST['unlimited'] == 200) { 

     $license = 'extended'; 

    } else { 

     $license = 'standard'; 

    } 

    if ($photograph->isValidPhotographSize($photograph_id, $_REQUEST['size_radio'])) { 

     $token_cost = $photograph->getTokenCost($_REQUEST['size_radio'], $_REQUEST['unlimited']); 
     $order = new ImageOrder($_SESSION['user']['id'], $_REQUEST['size_radio'], $license, $token_cost); 
     $order->saveOrder(); 
     $order->deductTokens(); 
     header('location: account.php'); 

    } else { 

     die("Please go back and select a valid photograph size"); 

    } 

} 


######CLASS CODE####### 
<?php 

include_once('database_classes.php'); 

class Order { 

    protected $account_id; 
    protected $cost; 
    protected $license; 

    public function __construct($account_id, $license, $cost) { 

     $this->account_id = $account_id; 
     $this->cost = $cost; 
     $this->license = $license; 

    } 

} 

class ImageOrder extends Order { 

    protected $size; 

    public function __construct($account_id, $size, $license, $cost) { 

     $this->size = $size; 

     parent::__construct($account_id, $license, $cost); 

    } 

    public function saveOrder() { 

     //$db = Connect::connect(); 
     //$account_id = $db->real_escape_string($this->account_id); 
     //$size = $db->real_escape_string($this->size); 
     //$license = $db->real_escape_string($this->license); 
     //$cost = $db->real_escape_string($this->cost); 

    } 

    public function deductTokens() { 

     $db = Connect::connect(); 
     $account_id = $db->real_escape_string($this->account_id); 
     $cost = $db->real_escape_string($this->cost); 
     $query = "UPDATE accounts set tokens=tokens-$cost WHERE id=$account_id"; 
     $result = $db->query($query); 

    } 

} 

?>

当我死了（“$查询”）;直接在查询之后，它会打印正确的语句，并且当我在MySQL中运行该查询时，它可以很好地工作。

$ action = $ _REQUEST ['action'];

account.php只是一个命令列表，从来没有调用downloads.php。只是尝试评论重定向，但我有同样的问题。我不明白它是如何被调用两次，死亡语句显示正确的查询，并且脚本不重新加载自己。

这里是我的Apache访问日志：

71.*** - - [22/May/2010:13:14:35 +0000] "POST /download.php?action=confirm_download&photograph_id=122 HTTP/1.1" 200 1951 "http://***.com/viewphotograph.php?photograph_id=122" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 (.NET CLR 3.5.30729)" 
71.*** - - [22/May/2010:13:14:36 +0000] "GET /download.php?action=place_order&photograph_id=122&size_radio=xsmall&unlimited=0 HTTP/1.1" 302 453 "http://*** .com/download.php?action=confirm_download&photograph_id=122" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 (.NET CLR 3.5.30729)" 
71.*** - - [22/May/2010:13:14:36 +0000] "GET /download.php?action=place_order&photograph_id=122&size_radio=xsmall&unlimited=0 HTTP/1.1" 302 453 "http://*** .com/download.php?action=confirm_download&photograph_id=122" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 (.NET CLR 3.5.30729)" 
71.*** - - [22/May/2010:13:14:36 +0000] "GET /account.php HTTP/1.1" 200 2626 "http://***.com/download.php?action=confirm_download&photograph_id=122" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 (.NET CLR 3.5.30729)"

据我所知，显然有些不对劲这里。但我无法弄清楚第二个请求来自哪里。

来源

2010-05-22 ThinkingInBits

调试总是比双眼好。准备运行的代码，不会被查看。 – 2010-05-22 12:04:18

我一直试图运行这个代码四个小时。我已经睡了36个小时了。 – ThinkingInBits 2010-05-22 12:05:25

如果我放了一个骰子（“$ query”）;在结果之前，它显示正确的查询。如果我把它放在$ result之后，它仍然显示正确的查询，但错误的数量仍然会被扣除。 – ThinkingInBits 2010-05-22 12:07:29