PHP - Strange Question - Updating File Automatically

<?php
include("config.inc.php");

if ($_SERVER['REQUEST_METHOD'] == "POST") 
{

 include("config.inc.php");
    if(!$_POST) {
    header("Location: preexport.php");
    exit();
} 

 
    // initialization
    $result_final = "";
    $counter = 0;

// List of our known photo types
    $known_photo_types = array(
                        'image/pjpeg' => 'jpg',
                        'image/jpeg' => 'jpg',
                        'image/gif' => 'gif',
                        'image/bmp' => 'bmp',
                        'image/x-png' => 'png'
                    );
   
// GD Function List
    $gd_function_suffix = array(
                        'image/pjpeg' => 'JPEG',
                        'image/jpeg' => 'JPEG',
                        'image/gif' => 'GIF',
                        'image/bmp' => 'WBMP',
                        'image/x-png' => 'PNG'
                    );
 
// Fetch the photo array sent by preexport.php
    $photos_uploaded = $_FILES['photo_filename'];
    $filename[]= $photos_uploaded['name'][$counter];
	//print_r($photos_uploaded);
  $photo_caption = $_POST['photo_caption'];

// Fetch the photo caption array
    $photo_description = $_POST['photo_description'];

// Fetch the photo caption array
    $photo_keyword = $_POST['photo_keyword'];
     
    while( $counter <count($_FILES['photo_filename']['tmp_name']) ) 
{
        if($photos_uploaded['size'][$counter] > 0)
        {
            if(!array_key_exists($photos_uploaded['type'][$counter], $known_photo_types))
            {
                $result_final .= "File ".($counter+1)." is not a photo<br />";
            }
            else
            {
			
			/*print "HHHHHH\n";
			print "Counter is $counter : ";
			print $photos_uploaded['name'][0];
			print $photos_uploaded['name'][1];
			print "Photo caption is $photo_caption[$counter]"; */
                mysqli_query(
                    $mysqli,"INSERT INTO
                        gallery_photos (
                    `photo_filename`,
		    `photo_caption`,
                    `photo_description`,
		    `photo_keywords`,
                    `category_name`
                    ) VALUES(
		        '".addslashes($photos_uploaded['name'][$counter])."',
                        '".addslashes($photo_caption[$counter])."',
                        '".addslashes($photo_description[$counter])."',
                        '".addslashes($photo_keyword[$counter])."',
                        '".addslashes($_POST['category'])."')"
                    ) or die(mysqli_error() . 'Photo not uploaded');
                   
               // $new_id = mysqli_insert_id();
                $filetype = $photos_uploaded['type'][$counter];
				
                $extention = $known_photo_types[$filetype];
                //$filename = $photo_filename[$counter].".".$extention;
		//$filename = $new_id.".".$extention;
 
              //  mysqli_query( "UPDATE gallery_photos SET photo_filename='".addslashes($filename)."' WHERE photo_id='".addslashes($new_id)."'" );
 
                // Store the orignal file
				
                copy($photos_uploaded['tmp_name'][$counter], $images_dir."/".$photos_uploaded['name'][$counter]);
 
                // Let's get the Thumbnail size
                $size = GetImageSize( $images_dir."/".$photos_uploaded['name'][$counter] );
                if($size[0] > $size[1])
                {
                    $thumbnail_width = 200;
                    $thumbnail_height = (int)(200 * $size[1] / $size[0]);
                }
                else
                {
                    $thumbnail_width = (int)(200 * $size[0] / $size[1]);
                    $thumbnail_height = 200;
                }
           
                // Build Thumbnail with GD 1.x.x, you can use the other described methods too
                $function_suffix = $gd_function_suffix[$filetype];
                $function_to_read = "ImageCreateFrom".$function_suffix;
                $function_to_write = "Image".$function_suffix;
 
                // Read the source file
                $source_handle = $function_to_read ( $images_dir."/".$photos_uploaded['name'][$counter] );
				
				$sharpenMatrix = array
                (
                    array(-1.2, -1, -1.2),
                    array(-1, 8, -1),
                    array(-1.2, -1, -1.2)
                );
 
                // calculate the sharpen divisor
                $divisor = array_sum(array_map('array_sum', $sharpenMatrix));          
 
                $offset = 0;
               
                if($source_handle)
                {
                    // Let's create an blank image for the thumbnail
                        $destination_handle = ImageCreateTrueColor ( $thumbnail_width, $thumbnail_height );
               
                    // Now we resize it
                    ImageCopyResized( $destination_handle, $source_handle, 0, 0, 0, 0, $thumbnail_width, $thumbnail_height, $size[0], $size[1] );
                }
 
                // Let's save the thumbnail
                $function_to_write( $destination_handle, $images_dir."/tb_".$photos_uploaded['name'][$counter], 100 );
                ImageDestroy($destination_handle );
                //

           
               
 
                $result_final .= "<img src='".$images_dir. "/tb_".$photos_uploaded['name'][$counter]."' /> File ".($counter+1)." Added<br />";
            }
        }
    $counter++;
    }
 
    // Print Result
echo <<<__HTML_END
 
<html>
<head>
    <title>Photos uploaded</title>
</head>
<body>
    $result_final
</body>
</html>
 
__HTML_END;

}
?>

<?php
 include 'config.inc.php';
 
  $photo_category_list = '';
 $photo_upload_fields = '';
 $counter = 1;
 
 // If we want more fields, then use, preexport.php?number_of_fields=9
 $number_of_fields = (isset($_GET['number_of_fields'])) ?
   (int)($_GET['number_of_fields']) : 9;
 
 // Firstly Lets build the Category List
 $result = mysqli_query($mysqli,'SELECT category_name FROM gallery_category');
 /*if($result === FALSE) {
    die(mysqli_error()); // TODO: better error handling
}*/
 while($row = mysqli_fetch_array($result)) {
   $photo_category_list .= <<<__HTML_END
<option value="$row[0]">$row[0]</option>\n
__HTML_END;
 }
 mysqli_free_result( $result ); 
 
 // Lets build the Image Uploading fields
 while($counter <= $number_of_fields) {
   $photo_upload_fields .= <<<__HTML_END
<tr><td>
 Photo {$counter}:
 <input name="photo_filename[]"
type="file" />
</td></tr>
<tr><td>
 Caption:
 <textarea name="photo_caption[]" cols="50"
   rows="1"></textarea>
</td></tr>
<tr><td>
 Description:
 <textarea name="photo_description[]" cols="50"
   rows="4"></textarea>
</td></tr>
<tr><td>
 Keyword:
 <textarea name="photo_keyword[]" cols="50"
   rows="4"></textarea>
</td></tr>
__HTML_END;
   $counter++;
 }
 
 // Final Output
 echo <<<__HTML_END
<html>
<head>
<title> Rajeev lets upload photos!! </title>
</head>
<body>
<form enctype="multipart/form-data"
 action="export.php" method="post"
 name="export_form">
 <table width="90%" border="0"
   align="center" style="width: 90%;">
   <tr><td>
     Select Category
     <select name="category">
     $photo_category_list
     </select>
   </td></tr>
   <!&#8212;Insert the image fields here -->
   $photo_upload_fields
   <tr><td>
     <input type="submit" name="submit"
       value="Add Photos" />
   </td></tr>
 </table>
</form>
</body>
</html>
__HTML_END;
?>

I need help here. I am creating a system where the user will be able to update the product stock by uploading the stock of the products according to the id that has been assigned to the product. 
this is how my products table in  looks like in mysql database

I tried the code below but all i could not update my data into my database. And there's not error shown on my code. I do not know what is wrong with my codes. Please help me.
below the code that i use for uploading the CSV file to the data of my product_stock. 

<?php 
include 'conn.php';
if(isset($_POST["add_stock"]))
{
 if($_FILES['product_file']['tmp_name'])
 {
  $filename = explode(".", $_FILES['product_file']['tmp_name']);
  if(end($filename) == "csv")
  {
   $handle = fopen($_FILES['product_file']['tmp_name'], "r");
   while($data = fgetcsv($handle))
   {
    $product_id = mysqli_real_escape_string($conn, $data[0]);
    $product_stock = mysqli_real_escape_string($conn, $data[1]);  
    $product_status = 1 ;
    $query = "UPDATE products SET `product_stock` = '$product_stock', `product_status` = '$product_status' WHERE id = '$product_id'";
    mysqli_query($conn, $query);
   }
   fclose($handle);
   header("location: upload-product.php?updation=1");
  }
  else
  {
   echo '<script>alert("An error occur while uploading product. Please try again.")
   window.location.href = "upload-product.php"</script>';
  }
 }
 else
 {
  echo '<script>alert("No file selected! ")
  window.location.href = "upload-product.php"</script>';
 }
}
if(isset($_GET["updation"]))
{
  echo '<script>alert("Product Stock Updated successfully!")</script>';
}
?>

 <div class="col-12">
            <div class="card card-user">
              <div class="card-header">
                <h5 class="card-title">Update Product Stock</h5>
                <div class="card-body">
                <div class="form-group">
				<label for="file">Update Products stock File (.csv file)</label>
                <a href="assets/templates/product-template.xlsx" title="Download Sample File (Fill In Information and Export As CSV File)" class="mx-2">
				<span class="iconify" data-icon="fa-solid:download" data-inline="false">
				</a>
                </div>
                <form class = "form" action="" method="post" name="uploadCsv" enctype="multipart/form-data">
                <div>
                <input type="file" name="product_file" accept=".csv">
                <div class="row">
                <div class="update ml-auto mr-auto">
                <button type="submit" class="btn btn-primary btn-round" name="add_stock"> Import .cvs file</button>
                </div>
                </div>
                </div>
                </div>
                </form>
                </div>
              </div>

This is the template that i require user to key in and saved it in CSV format before uploading it.