PHP study notes: e-commerce platform and online payment

<?php
// 连接数据库
$connection = new mysqli('localhost', 'username', 'password', 'database_name');

if ($connection->connect_error) {
    die('连接数据库失败：' . $connection->connect_error);
}

// 处理用户提交的表单数据
if (isset($_POST['submit'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];
    
    // 在数据库中插入新用户数据
    $sql = "INSERT INTO users (username, password) VALUES ('$username', '$password')";
    if ($connection->query($sql) === TRUE) {
        echo "注册成功";
    } else {
        echo "注册失败：".$connection->error;
    }
}
?>

<h1>用户注册</h1>
<form method="post" action="">
    <label for="username">用户名：</label>
    <input type="text" name="username" required><br>
    <label for="password">密码：</label>
    <input type="password" name="password" required><br>
    <input type="submit" name="submit" value="注册">
</form>

<?php
// 连接数据库
$connection = new mysqli('localhost', 'username', 'password', 'database_name');

if ($connection->connect_error) {
    die('连接数据库失败：' . $connection->connect_error);
}

// 处理用户提交的表单数据
if (isset($_POST['submit'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];
    
    // 查询数据库中的用户数据
    $sql = "SELECT * FROM users WHERE username='$username' AND password='$password'";
    $result = $connection->query($sql);
    
    // 验证用户登录信息
    if ($result->num_rows > 0) {
        echo "登录成功";
        // 在登录成功的情况下，可以跳转到用户的个人主页
    } else {
        echo "用户名或密码错误";
    }
}
?>

<h1>用户登录</h1>
<form method="post" action="">
    <label for="username">用户名：</label>
    <input type="text" name="username" required><br>
    <label for="password">密码：</label>
    <input type="password" name="password" required><br>
    <input type="submit" name="submit" value="登录">
</form>

<?php
// 处理用户提交的订单数据
if (isset($_POST['submit'])) {
    $productName = $_POST['product_name'];
    $productPrice = $_POST['product_price'];
    
    // 调用支付宝接口进行支付
    $gatewayUrl = 'https://openapi.alipay.com/gateway.do';
    $appId = 'your_app_id';
    $merchantPrivateKey = 'your_merchant_private_key';
    $alipayPublicKey = 'your_alipay_public_key';
    
    // 构建请求参数
    $requestParams = array(
        'app_id' => $appId,
        'method' => 'alipay.trade.page.pay',
        'charset' => 'utf-8',
        'sign_type' => 'RSA2',
        'timestamp' => date('Y-m-d H:i:s'),
        'version' => '1.0',
        'notify_url' => 'your_notify_url',
        'biz_content' => json_encode(array(
            'subject' => $productName,
            'out_trade_no' => uniqid(), // 生成唯一订单号
            'total_amount' => $productPrice,
            'product_code' => 'FAST_INSTANT_TRADE_PAY'
        ))
    );
    
    // 签名请求参数
    ksort($requestParams);
    $signString = '';
    foreach ($requestParams as $key => $value) {
        $signString .= $key.'='.urlencode($value).'&';
    }
    $signString = substr($signString, 0, -1);
    $signature = base64_encode(openssl_sign($signString, $merchantPrivateKey, OPENSSL_ALGO_SHA256));
    $requestParams['sign'] = $signature;
    
    // 生成最终支付链接
    $payUrl = $gatewayUrl . '?' . http_build_query($requestParams);
    
    // 重定向用户到支付宝页面进行支付
    header("Location: ".$payUrl);
    exit();
}
?>

<h1>在线支付</h1>
<form method="post" action="">
    <label for="product_name">商品名称：</label>
    <input type="text" name="product_name" required><br>
    <label for="product_price">商品价格：</label>
    <input type="number" name="product_price" required><br>
    <input type="submit" name="submit" value="支付">
</form>