Php PayPal IPN-如何在完成后更新数据库

我已经花了几个小时使用PayPal IPN，当状态为“完成”时，我无法让它更新数据库

我知道这方面有很多问题，但我就是想不出来。我想每个人都有不同的问题

我从互联网站上得到了部分脚本，因为我不太熟悉IPN的工作。请允许我分享我当前的代码（我将代码中不重要的部分灰显）：

<?php

// Connect my my own database and start the session that has the ID of the current account user
session_start();
include("connection.php");

/* Greying out
// STEP 1: Read POST data

// reading posted data from directly from $_POST causes serialization 
// issues with array data in POST
// reading raw POST data from input stream instead. 
$raw_post_data = file_get_contents('php://input');
$raw_post_array = explode('&', $raw_post_data);
$myPost = array();
foreach ($raw_post_array as $keyval) {
  $keyval = explode ('=', $keyval);
  if (count($keyval) == 2)
     $myPost[$keyval[0]] = urldecode($keyval[1]);
}
// read the post from PayPal system and add 'cmd'
$req = 'cmd=_notify-validate';
if(function_exists('get_magic_quotes_gpc')) {
   $get_magic_quotes_exists = true;
} 
foreach ($myPost as $key => $value) {        
   if($get_magic_quotes_exists == true && get_magic_quotes_gpc() == 1) { 
        $value = urlencode(stripslashes($value)); 
   } else {
        $value = urlencode($value);
   }
   $req .= "&$key=$value";
}


// STEP 2: Post IPN data back to paypal to validate

$ch = curl_init('https://www.sandbox.paypal.com/cgi-bin/webscr'); // change to [...]sandbox.paypal[...] when using sandbox to test
curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Connection: Close'));

// In wamp like environments that do not come bundled with root authority certificates,
// please download 'cacert.pem' from "http://curl.haxx.se/docs/caextract.html" and set the directory path 
// of the certificate as shown below.
// curl_setopt($ch, CURLOPT_CAINFO, dirname(__FILE__) . '/cacert.pem');
if( !($res = curl_exec($ch)) ) {
    // error_log("Got " . curl_error($ch) . " when processing IPN data");
    curl_close($ch);
    exit;
}
curl_close($ch);

*/

// STEP 3: Inspect IPN validation result and act accordingly
if (strcmp ($res, "VERIFIED") == 0) {
    // check whether the payment_status is Completed
    // check that txn_id has not been previously processed
    // check that receiver_email is your Primary PayPal email
    // check that payment_amount/payment_currency are correct
    // process payment

    // assign posted variables to local variables
    $item_name = $_POST['item_name'];
    $item_number = $_POST['item_number'];
    $payment_status = $_POST['payment_status'];
    if ($_POST['mc_gross'] != NULL)
        $payment_amount = $_POST['mc_gross'];
    else
        $payment_amount = $_POST['mc_gross1'];
    $payment_currency = $_POST['mc_currency'];
    $txn_id = $_POST['txn_id'];
    $receiver_email = $_POST['receiver_email'];
    $payer_email = $_POST['payer_email'];
    $custom = $_POST['custom'];

    if($payment_status == "Completed") {

        if(array_key_exists("id", $_COOKIE) AND $_COOKIE['id']) {

            $_SESSION["id"] = $_COOKIE["id"];

        }

        if(array_key_exists("id", $_SESSION) AND $_SESSION['id']) {

            // Update plan and due date to database
            $id = $_SESSION['id'];
            $due = date('Y-m-d', strtotime('+1 month'));

            $query = "UPDATE users SET plan = 'paid' , due_date = '".mysqli_real_escape_string($link, $due)."' WHERE id = ".$id." LIMIT 1";
            $result = mysqli_query($link, $query);

        }


    }

} else if (strcmp ($res, "INVALID") == 0) {
    // log for manual investigation

}

---

将PayPal交易id保存在数据库列中，并尝试使用保存的交易id使用数据库进行更新。使用IPN操作时，最好不要使用Cookies-会话

您能用您的验证条件代码替换下面的代码吗

（if（strcmp（$res，“VERIFIED”）==0{}下的代码）：

我希望以上能解决你的问题
 我已经弄明白了，但我知道如果我没有弄明白，我会非常感激的认可的。
$item_name = $_POST['item_name'];
$item_number = $_POST['item_number'];
$payment_status = $_POST['payment_status'];
if ($_POST['mc_gross'] != NULL)
    $payment_amount = $_POST['mc_gross'];
else
    $payment_amount = $_POST['mc_gross1'];
$payment_currency = $_POST['mc_currency'];
$txn_id = $_POST['txn_id'];
$receiver_email = $_POST['receiver_email'];
$payer_email = $_POST['payer_email'];
$custom = $_POST['custom'];

if($payment_status == "Completed") {
        $due = date('Y-m-d', strtotime('+1 month'));
        $query = "UPDATE users SET plan = 'paid' , due_date = '".mysqli_real_escape_string($link, $due)."' WHERE txn_id = '".$txn_id."'";
        $result = mysqli_query($link, $query);       

}