Merhaba php kısmında yardıma ihtiyacım var veri tabani bağlantısını doğru yapmıştım ama sistem arama çalışmadı nasıl yapabilirim kodları düzeltip bana buradan atabilir misiniz?

<?php
    
    include "scripts/perf_start.php";
    
    session_start();
    
    require_once "app.php";
    require_once "scripts/lang-switch.php";
    
    require_once "scripts/login_helpers.php";
    redirect_visitor("login.php?ref=" . $app["rel_req"]);
    
    require_once "scripts/session.php";
    $member = session_get_member();
    
?>
<!DOCTYPE html>
<html lang="tr">

<head>
    <meta charset="utf-8" />
    <title><?= _t("Dosyalar") ?></title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <base href="<?= $app["url"] ?>/" />
    <link rel="icon" type="image/x-icon" href="favicon.ico" />
    <link rel="stylesheet" href="css/styles.css" />
    <link rel="stylesheet" href="css/header.css" />
    <link rel="stylesheet" href="css/dashboard.css" />
    <link rel="stylesheet" href="css/files.css" />
</head>

<body>

    <?php
        $page = "files";
        include "template/header.php";
    ?>
    
    <main>
        <div class="container">
            
<?php
    
    session_print_error("download_id_invalid");
    session_print_error("download_db_missing");
    
    require_once "scripts/tools.php";
    
    if (is_approved()) {
        
        session_print_error("action_delete_file");
        session_print_message("action_delete_file");
        
        require_once "db/connection.php";
        require_once "models/FileUploadAgent.php";
        
        $fileupload_agent = new FileUploadAgent($db_agent->pdo);
        
        $files = [];
        
        require_once "scripts/requests.php";
        
        $id = GET("id");
        
        if ($id && preg_match('/^\d+$/', $id, $match)) {
            $file = $fileupload_agent->get_file_by_id($id);
            if ($file) {
                $files = [$file];
            } else {
                echo "Dosya bulunamadı.";
            }
        } else {
            $files = $fileupload_agent->get_files();
            $count = count($files);
            if ($count != 0) {
                echo "<span class='count'>{$count} " . _t("dosya bulundu") . ".</span>";
            } else {
                echo _t("Yüklü herhangi bir dosya bulunamadı.");
            }
        }
    
        if ($files) {
            
            require_once "scripts/element.php";
            
            $table = elem("table", null);
            $thead_rows = [];
            
            if (is_admin()) {
                $thead_rows[] = elem("td", ["class"=>"op"], "İşlemler");
            }
            $thead_rows[] = elem("td", ["class"=>"file"],         _t("Dosya"));
            $thead_rows[] = elem("td", ["class"=>"size"],         _t("Boyut"));
            $thead_rows[] = elem("td", ["class"=>"thumbnail"],    _t("Ön İzleme"));
            $thead_rows[] = elem("td", ["class"=>"description"],  _t("Açıklama"));
            if (is_admin() || is_mod()) {
                $thead_rows[] = elem("td", ["class"=>"date"],   "Yüklenme Tarihi");
                $thead_rows[] = elem("td", ["class"=>"email"],  "Yükleyen");
            }
            
            $thead = elem("thead", null, elem("tr", null, $thead_rows));
            $table->append($thead);
            
            for ($i = 0; $i < count($files); $i++) {
                $file = $files[$i];
                
                $thumbnail = "";
                if ($file["thumbnail"]) {
                    $thumbnail = elem("a", ["href"=>"uploads/images/". $file["thumbnail"], "target"=>"_blank"], elem("img", ["src"=>"uploads/images/". $file["thumbnail"], "class"=>"thumbnail"]));
                }
                
                $file_link = elem("a", ["href"=>"download.php?id=" . $file["id"], ], $file["name"]);
                
                $file_size = number_format(intval($file["size"]) / 1024, 2);
                $file_size = elem("span", ["title"=>"{$file["size"]} KB"], $file_size . " MB");
                
                $cells = [];
                if (is_admin() || is_mod()) {
                    if (is_admin()) {
                        $cells[] = elem("td", ["class"=>"op"], elem("a", ["href"=>"actions/delete_file.php?id={$file["id"]}&ref=files.php", "class"=>"button-chrome delete", "title"=>"Dosyayı Sil"], elem("img", ["src"=>"images/bin.png"])));
                    }
                }
                $cells[] = elem("td", ["class"=>"file"], $file_link);
                $cells[] = elem("td", ["class"=>"size"], $file_size);
                $cells[] = elem("td", ["class"=>"thumbnail"], $thumbnail);
                $cells[] = elem("td", ["class"=>"description"], $file["description"]);
                if (is_admin() || is_mod()) {
                    $cells[] = elem("td", ["class"=>"date"], $file["upload_date"]);
                    // $cells[] = elem("td", ["class"=>"email"], "asd");
                    
                    global $db_agent;
                    
                    $member_agent = new MemberAgent($db_agent->pdo);
                    
                    $uploader = $member_agent->get_member_by_id($file["uploader_id"]);
                    if ($uploader) {
                        $target_page = "users";
                        if ($uploader["role"] == "administrator") {
                            $target_page = "admins";
                        } else if ($uploader["role"] == "moderator") {
                            $target_page = "mods";
                        }
                        $uploader_link = elem("a", ["href"=>"{$target_page}.php?id=" . $uploader["id"]], $uploader["email"]);
                    } else {
                        $uploader_link = elem("span", ["title"=>"ID : {$file["uploader_id"]}"], $file["uploader_email"]);
                    }
                    $cells[] = elem("td", ["class"=>"email"], $uploader_link);
                }
                $row = elem("tr", null, $cells);
                $table->append($row);
            }
            
            $table->output();
            
        }
        
    } else {
        echo "<p>Hesabınız henüz onaylanmamış.</p>";
        echo "<p>Dosyaları hesabınız onaylandığında görüntüleyebilirsiniz.</p>";
    }
    
?>

        </div>
    </main>
    <script src="https://code.jquery.com/jquery-3.5.1.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/js/bootstrap.bundle.min.js"></script>
    
    <script>
        document.querySelectorAll(".delete").forEach(function (a) {
            a.addEventListener("click", function (e) {
                e.preventDefault();
                if (confirm("Dosya silinecek. Devam edilsin mi?")) {
                    location.href = this.href;
                }
            });
        });
    </script>
        </section>
</body>
</html>
<tbody>
<form action="" method="GET">
                                    <div class="input-group mb-3">
                                        <input type="text" name="search" required value="<?php if(isset($_GET['search'])){echo $_GET['search']; } ?>" class="form-control" placeholder="Search">
                                        <button type="submit" class="btn btn-primary">Arama</button>
                                    </div>
                                </form>
<?php 

                                    $con = mysqli_connect("localhost","user","password!","database");

                                    if(isset($_GET['search']))
                                    {
                                        $filtervalues = $_GET['search'];
                                        $query = "SELECT * FROM users WHERE CONCAT(id,name,size,description) LIKE '%$filtervalues%' ";
                                        $query_run = mysqli_query($con, $query);

                                        if(mysqli_num_rows($query_run) > 0)
                                        {
                                            foreach($query_run as $items)
                                            {
                                                ?>
                                                <tr>
                                                    <td><?= $items['id']; ?></td>
                                                    <td><?= $items['name']; ?></td>
                                                    <td><?= $items['size']; ?></td>
                                                    <td><?= $items['description']; ?></td>
                                                    <td><?= $items['thumbnail']; ?></td>
                                                </tr>
                                                <?php
                                            }
                                            
                                        }
                                        else
                                        {
                                            ?>
                                                <tr>
                                                    <td colspan="4">No Record Found</td>
                                                </tr>
                                            <?php
                                        }
                                    }
                                ?> 
                                </tbody>
<?php
    session_delete("errors", "messages");
    include "scripts/perf_end.php";