如何在php中将会话从用户名更改为id？答案

【问题标题】：How to change session from username to id in php?如何在php中将会话从用户名更改为id？
【发布时间】：2018-07-20 12:26:53
【问题描述】：

        // LOGIN USER
        if (isset($_POST['login_user'])) {
          $username = mysqli_real_escape_string($db, $_POST['username']);
          $password = mysqli_real_escape_string($db, $_POST['password']);

          if (empty($username)) {
            array_push($errors, "Username is required");
          }
          if (empty($password)) {
            array_push($errors, "Password is required");
          }

          if (count($errors) == 0) {
            $password = md5($password);
            $query = "SELECT * FROM register WHERE username='$username' AND password='$password'";
            $results = mysqli_query($db, $query);
        }   

            $qry = "SELECT * from register";
            $result = mysqli_query($qry);

            $row = mysqli_fetch_array($result);
            $id = $row[0];


            if (mysqli_num_rows($results) == 1) {
    //here i want to change session from username to id          
     $_SESSION['username'] = $username;
              $_SESSION['success'] = "You are now logged in";
              header('location: index.php');
            }else {
                array_push($errors, "Wrong username/password combination");
            }
          }
        ?>

此代码也有效，但我想将用户名会话替换为 id 会话。请帮助我如何用 id 替换它。在这里，我想将会话设置为用户名中的 id。所以请帮助我如何获得我的代码的解决方案。

【问题讨论】：

旁注：使用 MD5 密码而不是使用 password_hash() 安全地散列密码有什么特殊原因吗？或者这只是为了学术目的？ MD5 根本不安全。
当我更新用户配置文件时，会话由于更改设置的用户名而被破坏，这就是为什么我想用 id 作为会话替换用户名作为会话，而 md5 用于学术目的

标签： php mysql session

【解决方案1】：

只需复制此代码：替换你的代码

$_SESSION['username'] = $username;

到

$_SESSION['id'] = $username;

看起来像：

if (mysqli_num_rows($results) == 1) {
    //here i want to change session from username to id          
    $_SESSION['id'] = $username;
    $_SESSION['success'] = "You are now logged in";
    header('location: index.php');
}else {
    array_push($errors, "Wrong username/password combination");
}

【讨论】：

【解决方案2】：

你可以这样获取值，因为我们是把结果放入一个数组中

$row = mysqli_fetch_array($result);

$id = $row[0];

正确的方法如下

// LOGIN USER
    if (isset($_POST['login_user'])) {
      $username = mysqli_real_escape_string($db, $_POST['username']);
      $password = mysqli_real_escape_string($db, $_POST['password']);

      if (empty($username)) {
        array_push($errors, "Username is required");
      }
      if (empty($password)) {
        array_push($errors, "Password is required");
      }

      if (count($errors) == 0) {
        $password = md5($password);
        $query = "SELECT * FROM register WHERE username='$username' AND password='$password'";
        $results = mysqli_query($db, $query);
    }   

        $qry = "SELECT * from register";
        $result = mysqli_query($qry);

        $row = mysqli_fetch_array($result);

        // $id =  $row[0];

        $id = $row['id'];  //this is the primary key


        if (mysqli_num_rows($results) == 1) {         
          $_SESSION['id'] = $id;
          $_SESSION['success'] = "You are now logged in";
          header('location: index.php');
        }else {
            array_push($errors, "Wrong username/password combination");
        }
      }
    ?>

【讨论】：

【解决方案3】：

只需设置$_SESSION['id'] = $id。

【讨论】：