php - 如何使 PHP 页面只能在登录后才能访问

Question

我是 PHP 新手，正在尝试为作业组合一个原型(prototype)。我使用以下登录脚本以及填写用户名和密码的简单表单。一旦它根据数据库检查用户名和密码，如果匹配，则将用户带到welcome.php页面。如何使welcome.php 仅在用户成功登录后才可见？

<?php
include("web_config.php");

 session_start();

  if($_SERVER["REQUEST_METHOD"] == "POST") {
  // username and password sent from form 

  $myusername = mysqli_real_escape_string($mysqli,$_POST['username']);
  $mypassword = mysqli_real_escape_string($mysqli,$_POST['password']); 

  $sql = "SELECT UserAccountID FROM UserAccounts WHERE Username = '$myusername' and Password = '$mypassword'";
  $result = mysqli_query($mysqli,$sql);
  $row = mysqli_fetch_array($result,MYSQLI_ASSOC);
  $active = $row['active'];

  $count = mysqli_num_rows($result);

  // If result matched $myusername and $mypassword, table row must be 1 row

  if($count == 1) {
   echo "User logged in."; header("location: welcome.php");
   } else {


         $error = "Your Login Name or Password is invalid";
      }
   }
 ?>
  <div style = "font-size:11px; color:#cc0000; margin-top:10px"><?php    echo $error; ?></div>

Answer 1

您可能想看看Using sessions & session variables in a PHP Login Script其中已经包含了有关该主题的一些有用信息。