php网页注册程序 登陆

<?php
// 注册示例
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    $username = $_POST['username'];
    $password = password_hash($_POST['password'], PASSWORD_DEFAULT);

    // 连接数据库
    $conn = new mysqli('localhost', 'username', 'password', 'database');
    if ($conn->connect_error) {
        die("连接失败: " . $conn->connect_error);
    }

    // 插入用户信息
    $sql = "INSERT INTO users (username, password) VALUES ('$username', '$password')";
    if ($conn->query($sql) === TRUE) {
        echo "注册成功";
    } else {
        echo "错误: " . $sql . "<br>" . $conn->error;
    }

    $conn->close();
}
?>

<!-- 注册表单 -->
<form method="post">
    用户名: <input type="text" name="username"><br>
    密码: <input type="password" name="password"><br>
    <input type="submit" value="注册">
</form>

<?php
// 登录示例
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    $username = $_POST['username'];
    $password = $_POST['password'];

    // 连接数据库
    $conn = new mysqli('localhost', 'username', 'password', 'database');
    if ($conn->connect_error) {
        die("连接失败: " . $conn->connect_error);
    }

    // 查询用户信息
    $sql = "SELECT * FROM users WHERE username = '$username'";
    $result = $conn->query($sql);

    if ($result->num_rows > 0) {
        $row = $result->fetch_assoc();
        if (password_verify($password, $row['password'])) {
            echo "登录成功";
        } else {
            echo "密码错误";
        }
    } else {
        echo "用户名不存在";
    }

    $conn->close();
}
?>

<!-- 登录表单 -->
<form method="post">
    用户名: <input type="text" name="username"><br>
    密码: <input type="password" name="password"><br>
    <input type="submit" value="登录">
</form>