下面的代码首先是客户端代码，然后是类文件。
由于某种原因，“deductTokens()”方法调用了两次，从而对帐户收取双倍费用。
我整夜都在编程，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);
}
}
?>
当我死时（“$query”）；在查询之后，它直接打印正确的语句，当我在 MySQL 中运行该查询时，它工作得很好。
$action = $_REQUEST['action'];
account.php 只是一个订单列表，它永远不会调用 downloads.php。刚刚尝试注释掉重定向，但我遇到了同样的问题。我不明白它是如何被调用两次的，die 语句显示了正确的查询，并且脚本不会重新加载自身。
这是我的 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)"
我知道这里显然有问题。但我不知道第二个请求来自哪里。
