フロントエンドとバックエンドのphp5ビルドの完全なファイルのソースコード

<?php

// 连接数据库
$link = mysqli_connect("localhost", "root", "password", "database_name");

// 注册新用户
function register_user($username, $password) {
  global $link;
  $username = mysqli_real_escape_string($link, $username);
  $password = mysqli_real_escape_string($link, $password);
  $password = password_hash($password, PASSWORD_DEFAULT);
  $sql = "INSERT INTO users (username, password) VALUES (&#39;$username&#39;, &#39;$password&#39;)";
  mysqli_query($link, $sql);
}

// 用户登录
function login_user($username, $password) {
  global $link;
  $username = mysqli_real_escape_string($link, $username);
  $password = mysqli_real_escape_string($link, $password);
  $sql = "SELECT * FROM users WHERE username=&#39;$username&#39;";
  $result = mysqli_query($link, $sql);
  if (mysqli_num_rows($result) == 1) {
    $row = mysqli_fetch_assoc($result);
    if (password_verify($password, $row[&#39;password&#39;])) {
      $_SESSION[&#39;user&#39;] = $row[&#39;id&#39;];
      return true;
    }
  }
  return false;
}

// 修改用户信息
function update_user($username, $password) {
  global $link;
  $username = mysqli_real_escape_string($link, $username);
  $password = mysqli_real_escape_string($link, $password);
  $password = password_hash($password, PASSWORD_DEFAULT);
  $id = $_SESSION[&#39;user&#39;];
  $sql = "UPDATE users SET username=&#39;$username&#39;, password=&#39;$password&#39; WHERE id=&#39;$id&#39;";
  mysqli_query($link, $sql);
}

// 上传文件
function upload_file($filename, $filepath) {
  global $link;
  $filename = mysqli_real_escape_string($link, $filename);
  $filepath = mysqli_real_escape_string($link, $filepath);
  $user_id = $_SESSION[&#39;user&#39;];
  $sql = "INSERT INTO files (filename, filepath, user_id) VALUES (&#39;$filename&#39;, &#39;$filepath&#39;, &#39;$user_id&#39;)";
  mysqli_query($link, $sql);
}

// 管理文件
function manage_files() {
  global $link;
  $user_id = $_SESSION[&#39;user&#39;];
  $sql = "SELECT * FROM files WHERE user_id=&#39;$user_id&#39;";
  $result = mysqli_query($link, $sql);
  while ($row = mysqli_fetch_assoc($result)) {
    echo "<tr><td>{$row['filename']}</td><td>{$row['filepath']}</td><td><a href=&#39;delete_file.php?id={$row[&#39;id&#39;]}&#39;>Delete</a></td></tr>";
  }
}

// 删除文件
function delete_file($id) {
  global $link;
  $id = mysqli_real_escape_string($link, $id);
  $user_id = $_SESSION['user'];
  $sql = "DELETE FROM files WHERE id='$id' AND user_id='$user_id'";
  mysqli_query($link, $sql);
}
?>