更新用户个人资料图片不起作用

Question

我在更新用户个人资料图片时遇到问题。将数据粘贴到表单中并单击提交按钮后，显示“已更改”。除了个人资料图片外，一切都真的发生了变化。问题是图像没有存储在文件夹中。同时我不知道为什么。有人可以帮帮我吗？

<?php
session_start();
include_once 'dbconnect.php';

if (isset($_POST['ulozitzmeny']) && ($_SESSION['user']) && strlen($_SESSION['user']) > 0) {

    $first_name = mysql_real_escape_string($_POST['jmeno']);
    $last_name = mysql_real_escape_string($_POST['prijmeni']);
    $email = mysql_real_escape_string($_POST['email']);
    $password = hash('sha512', mysql_real_escape_string($_POST['heslo']));

    $file = rand(1000, 100000) . "-" . $_FILES['file']['name'];
    $file_loc = $_FILES['file']['tmp_name'];
    $file_size = $_FILES['file']['size'];
    $file_type = $_FILES['file']['type'];
    $folder = "images/";
    $new_size = $file_size / 1024;
    $new_file_name = strtolower($file);
    $final_file = str_replace(' ', '-', $new_file_name);
    move_uploaded_file($file_loc,$folder.$final_file);

    $res = mysql_query("SELECT password FROM users WHERE username='$_SESSION[user]'");
    $row = mysql_fetch_array($res);

    $sql = "SELECT file FROM users WHERE username='$_SESSION[user]'";
    $result_set = mysql_query($sql);
    $row2=mysql_fetch_array($result_set);

    if ($password != $row[0]) {

        echo" <div style='position:absolute;left:29.5%;top:10%;width:41%;' class='alert alert-danger fade in'>
             <a href='#' class='close' data-dismiss='alert' aria-label='close'>&times;</a>
             <strong>Chyba!</strong> Nespávné heslo!
             </div>";
    } else {

        if (mysql_query("UPDATE users SET first_name='$first_name', last_name='$last_name', email='$email', file='$final_file', type='$file_type', size='$new_size' WHERE username = '$_SESSION[user]'")or die(mysql_query)) {

            echo" <div style='position:absolute;left:29.5%;top:10%;width:41%;' class='alert alert-success'>
             <a href='#' class='close' data-dismiss='alert' aria-label='close'>&times;</a>
             <strong>Úspěch!</strong> Změny proběhly úspěšně!               
             </div>";
        }
    }
}
?>