我似乎无法找到为什么这个IPN代码没有更新数据库

Question

I ran this code without any errors but the database is not updating. I am receiving the variable data from Paypal correctly. To verify the Post data I added two lines at the beginning of the script to write the variables to a text file. The server uses php 5.4. I hope you guys can find the problem.

<?php  

/* checking for POST variables & writing to text file */
$posted_data = print_r($_POST,true);
file_put_contents('IPN_data.txt',$posted_data);

/* 
Database config here

*/

/* Connect to database */

$conn = new mysqli($db_host, $db_user, $db_pass, $db_database);
if ($conn->connect_error) {
            die("Connection failed: " . $conn->connect_error);
        } 
//read the post from PayPal system and add 'cmd' 
$req = 'cmd=_notify-validate'; 

foreach ($_POST as $key => $value) { 

$value = urlencode(stripslashes($value)); 
$req .= "&$key=$value"; 
} 

//post back to PayPal system to validate 
$header = "POST /cgi-bin/webscr HTTP/1.1
"; 
$header .= "Content-Type: application/x-www-form-urlencoded
"; 
$header .= "Host: www.sandbox.paypal.com
"; 
$header .= "Connection: close
"; 
$header .= "Content-Length: " . strlen($req) . "

"; 
$fp = fsockopen ('ssl://www.sandbox.paypal.com', 443, $errno, $errstr, 30); 
// 

$item = $_POST['item_name'];
$transaction_id = $_POST['txn_id'];
$payeremail = $_POST['payer_email'];

//error connecting to paypal 
if (!$fp) { 
// 
} 

//successful connection     
if ($fp) { 
fputs ($fp, $header . $req); 

while (!feof($fp)) { 
    $res = fgets ($fp, 1024); 
    $res = trim($res); //NEW & IMPORTANT 

    if (strcmp($res, "VERIFIED") == 0) { 
        //insert order into database     
     if (strcmp ($payment_status, "Completed") == 0) {

           /* update database */
           if($item == 'Learn HTML'){
                    $sql = "INSERT INTO dc_html (transaction_id,email_id)
                    VALUES ( '$transaction_id','$payeremail')";
                    $conn->close();
                    break;

           }

           if($item == 'Learn Css') {
                    $sql = "INSERT INTO dc_css (transaction_id,email_id)
                    VALUES ( '$transaction_id','$payeremail')";
                    $conn->close();
                    break;
           }



      }





    } 

    if (strcmp ($res, "INVALID") == 0) { 
        //insert into DB in a table for bad payments for you to process later 
    } 
} 

fclose($fp); 
} 

?> 

Answer 1

You seem to assign query to $sql variable but it does not appear in the code where you actually call a $conn->query($sql).

If you do not execute the query how could it get inserted into database?

Also adding some logging might help you debug more easily.

Like send an email or write an error to a file if

• postback fails
• db connection fails
• db query execution fails

Hope this helps.