PHP Web开发：通过URL参数传递按钮点击数据

<?php
$con = mysqli_connect("localhost", "root", "", "lectureHub");
if (!$con) {
    die("Could not connect to MySql Server:" . mysqli_error($con));
}

$query = "select * from lectures";
$result = mysqli_query($con, $query);

if ($result->num_rows > 0) {
    while ($row = $result->fetch_assoc()) {
        $lec_id = $row['lec_id'];
        $lec_name = $row['lec_name'];
        ?>
        <!-- 为每个按钮创建一个独立的表单 -->
        <form action="chapters.php" method="get" style="display:inline-block;">
            <input type="hidden" name="lec_id" value="<?php echo htmlspecialchars($lec_id); ?>">
            <button type="submit" class="btn btn-outline-primary lecture">
                <?php echo htmlspecialchars($lec_name); ?>
            </button>
        </form>
        <?php
    }
} else {
    echo "0 results";
}
mysqli_close($con);
?>

<?php
// 检查lec_id参数是否存在且非空
if (isset($_GET['lec_id']) && !empty($_GET['lec_id'])) {
    $received_lec_id = $_GET['lec_id'];

    $con = mysqli_connect("localhost", "root", "", "lectureHub");
    if (!$con) {
        die("Could not connect to MySql Server:" . mysqli_error($con));
    }

    // *** 关键：数据安全性 - 防止SQL注入 ***
    // 推荐使用预处理语句（Prepared Statements）
    $stmt = $con->prepare("SELECT * FROM chapters WHERE lec_id = ?");
    if ($stmt === false) {
        die("Prepare failed: " . htmlspecialchars($con->error));
    }
    $stmt->bind_param("s", $received_lec_id); // "s" 表示参数类型为字符串
    $stmt->execute();
    $result = $stmt->get_result();

    if ($result->num_rows > 0) {
        echo "<h2>章节列表 (讲座ID: " . htmlspecialchars($received_lec_id) . ")</h2>";
        echo "<ul>";
        while ($row = $result->fetch_assoc()) {
            echo "<li>" . htmlspecialchars($row['chapter_name']) . "</li>";
        }
        echo "</ul>";
    } else {
        echo "<p>未找到与讲座ID " . htmlspecialchars($received_lec_id) . " 相关的章节。</p>";
    }

    $stmt->close();
    mysqli_close($con);

} else {
    echo "<p>未接收到有效的讲座ID。</p>";
}
?>

<?php
// ... 数据库连接和查询 ...
if ($result->num_rows > 0) {
    while ($row = $result->fetch_assoc()) {
        $lec_id = $row['lec_id'];
        $lec_name = $row['lec_name'];
        echo "<button type='button' class='btn btn-outline-primary lecture' onclick='redirectToChapters(\"" . htmlspecialchars($lec_id) . "\")'>";
        echo htmlspecialchars($lec_name);
        echo "</button> ";
    }
} else {
    echo "0 results";
}
// ... 关闭数据库连接 ...
?>

<script>
function redirectToChapters(lecId) {
    // 构建包含lec_id参数的URL
    // encodeURIComponent 用于编码特殊字符，确保URL的有效性
    window.location.href = 'chapters.php?lec_id=' + encodeURIComponent(lecId);
}
</script>

<?php
// chapters.php 的代码与方法一中的接收部分完全相同
// ... （请参考方法一中的 chapters.php 代码） ...
?>