这是一个简单的登录页面和某处代码不工作在php - This is a simple login page and somewhere code is not working in php

这是一个登录表单的php代码。请帮助我检查我的代码4-5次，但没有找到这里的问题。问题是，我的if块执行成功，但其他部分不工作。我不知道这里发生了什么。请告诉我为什么我的代码不能正常执行。

<!DOCTYPE html>
<head>
</head>
<body>
    <form method="post" action="_SELF">
        <table>
        <tr><td>User<input type="text" name="fuser"/></td></tr>
        <tr><td>Password<input type="password" name="fpassword"/></td></tr>
        <tr><td><a href="#">Lost Password</a>&nbsp;<a href="form.php">Create new Account</a></td></tr>
        <tr><td><input type="submit" name="fsubmit" value="Login"/></td></tr>
        </table>
    </form>
</body>
</html>

PHP

<?php if(isset($_POST['fsubmit'])) { $hostname="localhost"; $username="root"; $dbpassword=""; $db="php"; $user=$_POST['fuser']; $password=$_POST['fpassword']; mysql_connect($hostname, $username, $dbpassword) or die("Server not Found, May be connection lost somewhere."); mysql_select_db($db) or die("Error Established, Database Not Connected."); $query="select * from register where user='$user' and password='$password'"; $rs=mysql_query($query) or die("Query not Executed, Some Fault."); while($r=mysql_fetch_assoc($rs)) { if($user==$r['user'] && $password==$r['password']) { header("Refresh:3; URL=dashboard.php"); } else { header("Refresh:1; URL=form.php"); } } } ?>

解决方案:
为什么要将传递的数据与查询的获取数据进行比较?它太过冗余，而且这种循环会减缓进程。如果有匹配，你所要做的就是使用*_num_rows。
还可以考虑在将表单中的POST数据绑定到查询中之前，使用_real_escape_string()对表单中的POST数据进行消毒，或者更好地使用预处理语句。
您的else语句将无法工作，因为当用户输入数据库中不存在的凭据时，它将不会进入循环，而循环往往不会读取if-else语句。
示例代码:
$user = mysql_real_escape_string($_POST['fuser']); $password = mysql_real_escape_string($_POST['fpassword']); $query = "SELECT * FROM register WHERE user = '$user' AND password = '$password'"; $rs = mysql_query($query) or die("Query not Executed, Some Fault."); if(mysql_num_rows($rs) > 0){ echo "<script>alert('You Are Login Successfully.')</script>"; echo "Please Wait We Moving Now, Don't Press F5 or Refresh Button"; header("Refresh:3; URL=dashboard.php"); } else { echo "<script>alert('Sorry Try Agian or Register First.')</script>"; echo "Please Wait We Moving Now, Don't Press F5 or Refresh Button"; header("Refresh:1; URL=form.php"); }
事先准备好的声明中:
提示: mysql_* API已弃用，建议使用mysqli_*。

首先使用mysqli_*:
建立连接
$con = new mysqli("localhost", "root", "", "php"); if (mysqli_connect_errno()) { printf("Connect failed: %s'n", mysqli_connect_error()); exit(); }
然后，继续你的代码:

$user = $_POST['fuser']; $password = $_POST['fpassword']; $stmt = $con->prepare("SELECT * FROM register WHERE user = ? AND password = ?"); $stmt->bind_param("ss", $user, $password); $stmt->execute(); $stmt->store_result(); if($stmt->num_rows > 0){ echo "<script>alert('You Are Login Successfully.')</script>"; echo "Please Wait We Moving Now, Don't Press F5 or Refresh Button"; header("Refresh:3; URL=dashboard.php"); } else { echo "<script>alert('Sorry Try Agian or Register First.')</script>"; echo "Please Wait We Moving Now, Don't Press F5 or Refresh Button"; header("Refresh:1; URL=form.php"); } $stmt->close();
安全:
在将密码存储在数据库中时也要考虑加密。我建议你至少使用password_hash。