如何设计一个可靠的MySQL表结构来实现文件存储功能？

CREATE TABLE `file` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  `path` varchar(255) NOT NULL,
  `size` int(11) NOT NULL,
  `type` varchar(255) NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

<?php

function uploadFile($file)
{
    $name = $file['name'];
    $path = 'uploads/' . $name;
    $size = $file['size'];
    $type = $file['type'];

    move_uploaded_file($file['tmp_name'], $path);

    $sql = "INSERT INTO `file` (`name`, `path`, `size`, `type`) VALUES ('$name', '$path', $size, '$type')";
    // 执行SQL语句插入文件信息

    return true;
}

function downloadFile($id)
{
    $sql = "SELECT `path` FROM `file` WHERE `id` = $id";
    // 执行SQL语句查询文件路径

    $path = $result['path'];

    header('Content-Type: application/octet-stream');
    header("Content-Disposition: attachment; filename="" . basename($path) . """);
    readfile($path);

    return true;
}

function deleteFile($id)
{
    $sql = "SELECT `path` FROM `file` WHERE `id` = $id";
    // 执行SQL语句查询文件路径

    $path = $result['path'];

    unlink($path);

    $sql = "DELETE FROM `file` WHERE `id` = $id";
    // 执行SQL语句删除文件信息

    return true;
}

?>