我在用户点击“删除”时编写了一个代码，但它没有删除该帐户，只是注销，我尝试在互联网上搜索，但没有发现任何帮助我。这是代码：
<?php include('server.php');
session_start();
if (isset($_GET['delete'])) {
$query = "DELETE FROM `users` WHERE `username` = '$username', `password`='$password'";
mysqli_query($db, $query);
session_destroy();
unset($_SESSION['username']);
unset($_SESSION['password']);
unset($_SESSION['money']);
header("location: login.php");
}
?>
这段代码有什么解决方案吗？我应该使用AND而不是逗号，因为它没有那样工作，也许有一个错误。 $query具有与phpmyadmin相同的代码，并且在那里取得了成功。
抱歉，server.php以下是代码：
使用md5加密密码也不是一个好主意，我可能需要改变它。
这是login.php，其中第一个代码来自（注册按钮未正确编程）：
<?php include('server.php');
session_start();
if (isset($_GET['delete'])) {
$stmt = $db->prepare('DELETE FROM users WHERE username = ? AND password = ?');
$stmt->bind_param('ss', $_SESSION['username'], $_SESSION['password']); // 's' specifies the variable type => 'string'
$stmt->execute();
session_destroy();
unset($_SESSION['username']);
unset($_SESSION['password']);
unset($_SESSION['money']);
header("location: login.php");
}
?>
<!DOCTYPE html>
<html>
<head>
<title>Login</title>
<link rel="stylesheet" type="text/css" href="style.css">
<script>
function register() {
header("location: register.php");
}
</script>
</head>
<body>
</br>
</br>
</br>
</br>
</br>
</br>
</br>
</br>
<form method="post" action="login.php" align="center">
<?php include('errors.php'); ?>
<div class="input-group">
<label>Username</label>
<input type="text" name="username" >
</div>
<div class="input-group">
<label>Password</label>
<input type="password" name="password">
</div>
<br/>
<div class="input-group">
<button type="submit" class="btn" name="login_user">Login</button>
</div>
<p></p></br>
<p>
<small class="input-group"> Not yet a member? </small> <button type="button" class="btn2" onclick="register()" name="register">Register</button>
</p>
</form>
</body>
</html>这是register.php：
<?php include('server.php') ?>
<!DOCTYPE html>
<html>
<head>
<title>Registration system PHP and MySQL</title>
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
</br></br></br></br></br></br></br>
<div class="header">
<h2>Register</h2>
</div>
<form method="post" action="register.php">
<?php include('errors.php'); ?>
<div class="input-group">
<label>Username</label>
<input type="text" name="username" value="<?php echo $username; ?>">
</div>
<div class="input-group">
<label>Email</label>
<input type="email" name="email" value="<?php echo $email; ?>">
</div>
<div class="input-group">
<label>Password</label>
<input type="password" name="password_1">
</div>
<div class="input-group">
<label>Confirm password</label>
<input type="password" name="password_2">
</div>
<div class="input-group">
<button type="submit" class="btn" name="reg_user">Register</button>
</div>
<p>
Already a member? <a href="login.php">Sign in</a>
</p>
</form>
</body>
</html>这是errors.php：
<?php if (count($errors) > 0) : ?>
<div class="error">
<?php foreach ($errors as $error) : ?>
<p><?php echo $error ?></p>
<?php endforeach ?>
</div>
<?php endif ?>这是index.php：
<?php
session_start();
if (!isset($_SESSION['username'])) {
$_SESSION['msg'] = "You must log in first";
header('location: login.php');
}
if (isset($_GET['logout'])) {
session_destroy();
unset($_SESSION['username']);
unset($_SESSION['password']);
unset($_SESSION['money']);
header("location: login.php");
}
?>
<!DOCTYPE html>
<html>
<head>
<title>Home</title>
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
<div class="content">
<!-- notification message -->
<?php if (isset($_SESSION['success'])) : ?>
<div class="error success" >
<h3>
<?php
echo $_SESSION['success'];
unset($_SESSION['success']);
?>
</h3>
</div>
<?php endif ?>
<!-- logged in user information -->
<?php if (isset($_SESSION['username'])) : ?>
<p>Welcome <strong><?php echo $_SESSION['username']; ?></strong></p>
<p> <a href="index.php?logout='1'" style="color: red;">logout</a> </p>
<p> <a href="login.php?delete='1'" style="color: red;">delete</a> </p>
<?php endif ?>
</div>
</body>
</html>不知道server.php的内容是什么，我可以看到一些错误。首先，您的代码容易受到SQL注入攻击。在SO上有关于此的几个主题，而是读取一个here。
从您的代码开始 - $db，$username，$password未定义。从下一行猜测，它必须是$_SESSION['username']和$_SESSION['password']。
此外，SQL对我来说看起来不合适，但这是我不确定的一件事 - 根据我的大脑它应该是
$stmt = $db->prepare('DELETE FROM users WHERE username = ? AND password = ?');
$stmt->bind_param('ss', $_SESSION['username'], $_SESSION['password']); // 's' specifies the variable type => 'string'
$stmt->execute();
另外，我希望你不要以明文存储密码。