Converting multiple photos by size in php - php

Question

Here is my code of importing and converting a photo into database and in a path on server drive.
I want to upload multiple photos in database and convert all of them in a smaller size. For example when I press button "chose file" I want to select more than one photo , and submit all of them. After they need to go in my database, and to convert into a smaller size (all of them, not only one).
<?php include("config.php") ?>
<?php
$name = '';
$type = '';
$size = '';
$error = '';
function compress_portrait($source_url, $destination_url, $quality) {
$info = getimagesize($source_url);
if ($info['mime'] == 'image/jpeg')
$image = imagecreatefromjpeg($source_url);
elseif ($info['mime'] == 'image/gif')
$image = imagecreatefromgif($source_url);
elseif ($info['mime'] == 'image/png')
$image = imagecreatefrompng($source_url);
imagejpeg($image, $destination_url, $quality);
return $destination_url;
} if ($_POST) {
if ($_FILES["portrait"]["error"] > 0) {
$error = $_FILES["portrait"]["error"];
}
else if (($_FILES["portrait"]["type"] == "image/gif") ||
($_FILES["portrait"]["type"] == "image/jpeg") ||
($_FILES["portrait"]["type"] == "image/png") ||
($_FILES["portrait"]["type"] == "image/pjpeg")) {
$fname=$_FILES['portrait']['name'];
$url = ('upload/portrait/'.$fname );
$filename = compress_portrait($_FILES["portrait"]["tmp_name"], $url, 50);
$query="INSERT into gallery (`USER_CODE`,`FILE_NAME`,`FILE_SIZE`,`FILE_TYPE`, `CATEGORY`) VALUES('$user_id','$fname','$file_size','$file_type' , 'portrait'); ";
mysqli_query($con , $query);
}}else {
$error = "Uploaded image should be jpg or gif or png";
}
?>
<div class="container align-center" >
<h1 class="mt-3">Add Images on Gallery</h1>
<h4 style="margin-top: 12px; ">Portrait:</h4>
<form action="" method="POST" id="img_compress" enctype="multipart/form-data">
<input type="file" name="portrait" id="portrait" multiple/>
<input type="submit" name="submit" id="submit" class="submit btn-primary"/>
</form>
</div>