修改PayPal IPN侦听器以在付款完成时处理多个查询

由于缺乏PHP知识，我在修改PayPal IPN侦听器时遇到了问题。

付款完成后，我的IPN侦听器将交易的详细信息插入到"付款"表中，但我现在需要脚本来更新另一个名为"会员"的表，这样我就可以很容易地判断谁付款了。

这就是我提出的SQL：

"UPDATE `Members` SET paid='TRUE' WHERE id='".$data['custom']."'

我使用IPN变量"自定义"从原始支付表单发送用户ID。

我曾尝试在脚本中实现mysqli_multi_query，但没有成功。我真的被这件事卡住了，如果有人能给我指明正确的方向，那就太棒了。

这是我的PHP：

function check_txnid($tnxid){
    global $link;
    return true;
    $valid_txnid = true;
    //get result set
    $sql = mysql_query("SELECT * FROM `payments` WHERE txnid = '$tnxid'", $link);       
    if($row = mysql_fetch_array($sql)) {
        $valid_txnid = false;
    }
    return $valid_txnid;
}
function check_price($price, $id){
    $valid_price = false;
    //you could use the below to check whether the correct price has been paid for the product
    /* 
    $sql = mysql_query("SELECT amount FROM `products` WHERE id = '$id'");       
    if (mysql_numrows($sql) != 0) {
        while ($row = mysql_fetch_array($sql)) {
            $num = (float)$row['amount'];
            if($num == $price){
                $valid_price = true;
            }
        }
    }
    return $valid_price;
    */
    return true;
}
function updatePayments($data){ 
    global $link;
    if(is_array($data)){                
        $sql = mysql_query("INSERT INTO `payments` (txnid, payment_amount, payment_status, itemid, createdtime) VALUES (
                '".$data['txn_id']."' ,
                '".$data['payment_amount']."' ,
                '".$data['payment_status']."' ,
                '".$data['item_number']."' ,
                '".date("Y-m-d H:i:s")."' 
                )", $link);
    return mysql_insert_id($link);
    }
}
//Database Connection
$link = mysql_connect($host, $user, $pass);
mysql_select_db($db_name);
// Check if paypal request or response
if (!isset($_POST["txn_id"]) && !isset($_POST["txn_type"])){
    // Firstly Append paypal account to querystring
    $querystring .= "?business=".urlencode($paypal_email)."&";  
    // Append amount& currency (£) to quersytring so it cannot be edited in html
    //The item name and amount can be brought in dynamically by querying the $_POST['item_number'] variable.
    $querystring .= "item_name=".urlencode($item_name)."&";
    $querystring .= "amount=".urlencode($item_amount)."&";
    //loop for posted values and append to querystring
    foreach($_POST as $key => $value){
        $value = urlencode(stripslashes($value));
        $querystring .= "$key=$value&";
    }
    // Append paypal return addresses
    $querystring .= "return=".urlencode(stripslashes($return_url))."&";
    $querystring .= "cancel_return=".urlencode(stripslashes($cancel_url))."&";
    $querystring .= "notify_url=".urlencode($notify_url);
    // Append querystring with custom field
    //$querystring .= "&custom=".USERID;
    // Redirect to paypal IPN
    header('location:https://www.paypal.com/cgi-bin/webscr'.$querystring);
    exit();
}else{
    // Response from Paypal
    // read the post from PayPal system and add 'cmd'
    $req = 'cmd=_notify-validate';
    foreach ($_POST as $key => $value) {
        $value = urlencode(stripslashes($value));
        $value = preg_replace('/(.*[^%^0^D])(%0A)(.*)/i','${1}%0D%0A${3}',$value);// IPN fix
        $req .= "&$key=$value";
}
    // assign posted variables to local variables
    $data['item_name']          = mysql_real_escape_string($_POST['item_name']);
    $data['item_number']        = mysql_real_escape_string($_POST['item_number']);
    $data['payment_status']     = mysql_real_escape_string($_POST['payment_status']);
    $data['payment_amount']     = mysql_real_escape_string($_POST['mc_gross']);
    $data['payment_currency']   = mysql_real_escape_string($_POST['mc_currency']);
    $data['txn_id']             = mysql_real_escape_string($_POST['txn_id']);
    $data['receiver_email']     = mysql_real_escape_string($_POST['receiver_email']);
    $data['payer_email']        = mysql_real_escape_string($_POST['payer_email']);
    $data['custom']             = mysql_real_escape_string($_POST['custom']);
    // post back to PayPal system to validate
    $header = "POST /cgi-bin/webscr HTTP/1.0'r'n";
    $header .= "Content-Type: application/x-www-form-urlencoded'r'n";
    $header .= "Content-Length: " . strlen($req) . "'r'n'r'n";
    $fp = fsockopen ('ssl://www.paypal.com', 443, $errno, $errstr, 30); 
    if (!$fp) {
        // HTTP ERROR
    } else {    
        fputs ($fp, $header . $req);
        while (!feof($fp)) {
            $res = fgets ($fp, 1024);
            if (strcmp($res, "VERIFIED") == 0) {
                // Used for debugging
                //@mail("you@youremail.com", "PAYPAL DEBUGGING", "Verified Response<br />data = <pre>".print_r($post, true)."</pre>");
                // Validate payment (Check unique txnid & correct price)
                $valid_txnid = check_txnid($data['txn_id']);
                $valid_price = check_price($data['payment_amount'], $data['item_number']);
                // PAYMENT VALIDATED & VERIFIED!
                if($valid_txnid && $valid_price){               
                    $orderid = updatePayments($data);       
                    if($orderid){                   
                        // Payment has been made & successfully inserted into the Database                              
                    }else{                              
                    // Error inserting into DB
                    // E-mail admin or alert user
                    }
                }else{                  
                    // Payment made but data has been changed
                    // E-mail admin or alert user
                }                       
            }else if (strcmp ($res, "INVALID") == 0) {
                // PAYMENT INVALID & INVESTIGATE MANUALY! 
                // E-mail admin or alert user
                // Used for debugging
                //@mail("you@youremail.com", "PAYPAL DEBUGGING", "Invalid Response<br />data = <pre>".print_r($post, true)."</pre>");
            }       
        }       
    fclose ($fp);
    }   
}
?>