重命名图像并在DB中存储名称

Question

如何将文件重命名为随机名称，然后将文件名和扩展名存储在数据库中。我会用它来改变个人资料图片。 我在这里有这个代码：     Валидниформати：“jpeg”，“jpg”，“png”';

    if(isset($_POST["submit"])) {

        $target_dir = "avatars/";
        $target_file = $target_dir . basename($_FILES["file"]["name"]);
        $uploadOk = 1;
        $allowedFiles =  array('gif','png' ,'jpg', 'jpeg', 'GIF', 'PNG', 'JPG', 'JPEG');
        $imageFileType = pathinfo($target_file,PATHINFO_EXTENSION);
        $check = getimagesize($_FILES["file"]["tmp_name"]);

        if($check !== false) {
            $imageError = "File is an image - " . $check["mime"] . ".";
            $uploadOk = 1;
        } else {
            $imageError = "<span style='color: red;'>Това не е снимка</span>";
            $uploadOk = 0;
        }

        if (file_exists($target_file)) {
            $imageError = "<span style='color: red;'>Снимката съществува</span>";
            $uploadOk = 0;
        }

        if ($_FILES["file"]["size"] > 500000) {
            $imageError = "<span style='color: red;'>Твърде голям файл</span>";
            $uploadOk = 0;
        }

        /*
        if ($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg" && $imageFileType != "gif") {
            $imageError = "<span style='color: red;'>Допустими формати: JPG, JPEG, PNG, GIF</span>";
            $uploadOk = 0;
        }
        */

        if (!in_array($imageFileType, $allowedFiles)) {
            $imageError = "<span style='color: red;'>Допустими формати: JPG, JPEG, PNG, GIF</span>";
            $uploadOk = 0;
        }

        if ($uploadOk == 1) {
            if (move_uploaded_file($_FILES["file"]["tmp_name"], $target_file)) {
                $imageError = "<span style='color: red;'>Файлът е качен успешно</span>";
            } else {
                $imageError = "<span style='color: red;'>Грешка при качване</span>";
            }
        }  
    }
    ?>