Question

<div id="nav">  
<div id="nav_wrapper"><br/>
<ul>
<li><a href="#">ホーム</a></li>
<li><a href="#">About</a></li>
<li><a href="login.html">ログイン</a></li>
</ul>
</div>

这是我的登录按钮所在的nagivation栏

<?php
session_start();

include "connection.php";

$username = mysqli_real_escape_string($conn,$_POST['user']);
$password = mysqli_real_escape_string($conn,$_POST['pass']);

$sql = "Select * from user where username = '".$username.
"' and password = '".md5($password)."'";
$result = mysqli_query($conn, $sql);

if(mysqli_num_rows($result)<=0)
{
    $sql = "Select * from user where username = '".$username.
    "' and password = '".$password."'";
    $result = mysqli_query($conn, $sql);

    if(mysqli_num_rows($result)<=0)
    {
        echo "<script>alert('Wrong username / password! Please try again!');";
        die("window.history.go(-1);</script>");
    }
}

if($row=mysqli_fetch_array($result))
{
    $_SESSION['username'] = $row['username'];
    $_SESSION['password'] = $row['password'];
    $_SESSION['role'] = $row['role'];
}

if($_SESSION['role']==="1")
{
    echo "<script>alert('Welcome back! ".$_SESSION['username']."');";
    echo "window.location.href='index.html';</script>";
}
else if($_SESSION['role']==="0")
{
    echo "<script>alert('Welcome back, Admin!');";
    echo "window.location.href='admin.html';</script>";
}
else
{
    echo "<script>window.location.href='login.html';</script>";
}
?>

这是我的login.html，我可以知道如何在用户登录后用logout替换登录吗？我以前见过一些问题，但我无法理解。抱歉愚蠢的问题因为我还是html的新手

Answer 1

假设你要在他们退出时破坏会话 - 这样的事情应该有用......

if(isset($_SESSION['username'])){
      echo //logout button here
  } else {
      echo //log in button here
  }

md5也不是很安全 - 为什么要将密码发布到会话变量？

Answer 2

您只需比较SESSION值即可确定用户是否已登录。

if(empty($_SESSION['username']))
{
    echo '<li><a href="login.html">ログイン</a></li>';
}else
{
    echo '<li><a href="logout.html">Logout</a></li>';
}

并尝试不使用md5加密密码。请改用PHP's own password hashing algos。也使用prepared statements，因为转义字符串也不安全。

也不要在会话中存储密码和其他敏感信息，它们很容易被劫持。

用户登录后如何用注销替换登录？

2 个答案: