php会员系统思路

<?php
// 示例代码：用户登录
$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);
}

$sql = "SELECT * FROM users WHERE username = '$username' AND password = '$password'";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    echo "登录成功";
} else {
    echo "用户名或密码错误";
}

$conn->close();
?>

<?php
// 示例代码：权限验证
$user_id = $_SESSION['user_id'];
$required_permission = "admin";

// 查询用户权限
$sql = "SELECT * FROM user_permissions WHERE user_id = $user_id AND permission = '$required_permission'";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    echo "权限验证通过";
} else {
    echo "权限不足";
}
?>