Upload multiple images to database - php

Question

the 5 pictures i want to upload are used to display the product with a gallery that you click on each image to see individually, i'm new to this so any feedback on how to improve my code is appreciated :)
config.php:
<?php
session_start();
// connect to database
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "ecommerce_site";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
?>
manage.php:
<form method="POST" action="manage.php" enctype="multipart/form-data">
<input type="file" name="image[]" multiple>
<button type="submit" name="upload_product">Post</button>
</form>
admin-functions.php:
<?php
if (isset($_POST['upload_product'])){
$filecount = count($_FILES['image']['name']);
for($i = 0 ; $i < $filecount ; $i++){
$filename = $_FILES['image']['name'][$i];
$sql = "INSERT INTO products (picture, picture_2, picture_3, picture_4, picture_5) VALUES ('$filename', '$filename', '$filename', '$filename', '$filename',)";
if($conn->query($sql) === TRUE){
echo"success";
}
else{
echo "error";
}
move_uploaded_file($_FILES['image']['tmp_name'][$i], '../static/images/'.$filename);
}
}
$result = mysqli_query($conn, "SELECT * FROM products");
?>
database