PHP表单批量更新：处理循环生成的多组输入并优化数据库交互

<?php
// 假设 $connection 是已建立的数据库连接
// 假设 $_SESSION['logged_in'] 存储了用户ID
isset($_REQUEST['username']) ? $username = $_REQUEST['username'] : header("Location: login.php");

if (isset($_SESSION['logged_in'])) {
    $user_id = $_SESSION['logged_in'];
}

$stmt = $connection->prepare("SELECT id, filename, image_title, image_tags FROM lj_imageposts WHERE user_id = :user_id");
$stmt->execute([':user_id' => $user_id]);
?>

<form method="post" enctype="multipart/form-data">
    <?php while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) { ?>
        <div class="upload-details-component">
            <div class="form-row">
                @@##@@">
            </div>
            <div class="edit-zone">
                <div class="form-row">
                    <label for="upload-details-title-<?php echo $row['id']; ?>">Image Title</label>
                    <!-- 使用数组命名 image-title[] -->
                    <input id="upload-details-title-<?php echo $row['id']; ?>" type="text" name="image-title[]" value="<?php echo htmlspecialchars($row['image_title']); ?>">
                </div>
                <div class="form-row">
                    <label for="upload-details-tags-<?php echo $row['id']; ?>">Comma Separated Image Tags</label>
                    <!-- 使用数组命名 image-tags[] -->
                    <textarea id="upload-details-tags-<?php echo $row['id']; ?>" name="image-tags[]"><?php echo htmlspecialchars($row['image_tags']); ?></textarea>
                </div>
                <div class="form-row">
                    <!-- 隐藏字段也使用数组命名，用于传递每条记录的唯一标识 -->
                    <input type="hidden" name="image-id[]" value="<?php echo htmlspecialchars($row['id']); ?>">
                </div>
            </div>
        </div>
    <?php } ?>
    <button type="submit" name="upload-submit">COMPLETE UPLOAD</button>
</form>

<?php
if (isset($_POST['upload-submit'])) {
    // 确保所有必需的数组都存在
    if (isset($_POST['image-title'], $_POST['image-tags'], $_POST['image-id']) &&
        is_array($_POST['image-title']) && is_array($_POST['image-tags']) && is_array($_POST['image-id'])) {

        // 准备SQL更新语句
        $sql = "UPDATE lj_imageposts SET
            image_title = :image_title,
            image_tags = :image_tags
            WHERE id = :id"; // 使用ID作为更新条件是最佳实践
        $stmt = $connection->prepare($sql);

        // 遍历其中一个数组，通过索引访问其他数组的对应值
        foreach ($_POST['image-id'] as $key => $id) {
            $image_title = $_POST['image-title'][$key] ?? ''; // 使用null合并运算符处理可能为空的值
            $image_tags = $_POST['image-tags'][$key] ?? '';

            try {
                $stmt->execute([
                    ':image_title' => $image_title,
                    ':image_tags' => $image_tags,
                    ':id' => $id
                ]);
            } catch (PDOException $e) {
                // 记录错误或向用户显示错误信息
                error_log("Database update error for ID {$id}: " . $e->getMessage());
                // 可以选择中断循环或继续处理
            }
        }

        // 重定向或显示成功消息
        header("Location: upload-details.php?username={$username}");
        exit(); // 确保重定向后终止脚本执行

    } else {
        // 处理数据不完整的情况
        echo "Error: Missing or invalid form data.";
    }
}
?>

<?php
// 假设 $connection 和 $user_id 已定义
$stmt = $connection->prepare("SELECT id, filename, image_title, image_tags FROM lj_imageposts WHERE user_id = :user_id");
$stmt->execute([':user_id' => $user_id]);
?>

<form method="post" enctype="multipart/form-data">
    <?php while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) { ?>
        <div class="upload-details-component">
            <div class="form-row">
                @@##@@">
            </div>
            <div class="edit-zone">
                <div class="form-row">
                    <label for="upload-details-title-<?php echo $row['id']; ?>">Image Title</label>
                    <!-- 使用关联数组命名 image-title[ID] -->
                    <input id="upload-details-title-<?php echo $row['id']; ?>" type="text" name="image-title[<?php echo $row['id']; ?>]" value="<?php echo htmlspecialchars($row['image_title']); ?>">
                </div>
                <div class="form-row">
                    <label for="upload-details-tags-<?php echo $row['id']; ?>">Comma Separated Image Tags</label>
                    <!-- 使用关联数组命名 image-tags[ID] -->
                    <textarea id="upload-details-tags-<?php echo $row['id']; ?>" name="image-tags[<?php echo $row['id']; ?>]"><?php echo htmlspecialchars($row['image_tags']); ?></textarea>
                </div>
                <!-- 注意：此时不再需要单独的隐藏ID字段，因为ID已经作为键包含在其他字段的name中 -->
            </div>
        </div>
    <?php } ?>
    <button type="submit" name="upload-submit">COMPLETE UPLOAD</button>
</form>

<?php
if (isset($_POST['upload-submit'])) {
    if (isset($_POST['image-title'], $_POST['image-tags']) &&
        is_array($_POST['image-title']) && is_array($_POST['image-tags'])) {

        $sql = "UPDATE lj_imageposts SET
            image_title = :image_title,
            image_tags = :image_tags
            WHERE id = :id";
        $stmt = $connection->prepare($sql);

        // 直接遍历 image-title 数组，键就是ID
        foreach ($_POST['image-title'] as $id => $title) {
            $image_title = $title ?? ''; // 当前图片的标题
            $image_tags = $_POST['image-tags'][$id] ?? ''; // 通过ID获取对应标签

            try {
                $stmt->execute([
                    ':image_title' => $image_title,
                    ':image_tags' => $image_tags,
                    ':id' => $id
                ]);
            } catch (PDOException $e) {
                error_log("Database update error for ID {$id}: " . $e->getMessage());
            }
        }

        header("Location: upload-details.php?username={$username}");
        exit();
    } else {
        echo "Error: Missing or invalid form data.";
    }
}
?>