数据库文件重命名返回JSON结果；图片上传至数据库重命名返回JSON新名称

I'll walk you through implementing both of your requested features in PHP, with proper JSON responses and best practices.

1. Database File Rename Function (with JSON Output) #

If you're looking to rename an actual database file (e.g., a SQLite .db file—note: avoid renaming MySQL data files while the server is running), here's a robust function that handles the operation and returns a JSON-formatted result:

<?php
function renameDatabaseFile(string $oldFilePath, string $newFilePath): void {
    $response = [];

    // Check if the original file exists
    if (!file_exists($oldFilePath)) {
        $response = [
            'status' => 'error',
            'message' => 'Target database file does not exist',
            'old_filename' => basename($oldFilePath)
        ];
    } 
    // Attempt to rename the file
    elseif (rename($oldFilePath, $newFilePath)) {
        $response = [
            'status' => 'success',
            'message' => 'Database file renamed successfully',
            'old_filename' => basename($oldFilePath),
            'new_filename' => basename($newFilePath)
        ];
    } 
    else {
        $response = [
            'status' => 'error',
            'message' => 'Failed to rename database file: ' . error_get_last()['message'],
            'old_filename' => basename($oldFilePath)
        ];
    }

    // Send JSON response
    header('Content-Type: application/json');
    echo json_encode($response);
    exit;
}

// Example usage (uncomment to test)
// renameDatabaseFile('./data/old_db.db', './data/new_db_v2.db');
?>

Key Notes: #

• Always verify the file exists before attempting a rename to avoid silent failures.
• The error_get_last() function captures specific errors if the rename fails (e.g., permission issues).
• We set the Content-Type header to application/json to ensure the response is properly interpreted by clients.

2. Image Upload to Database (with Renaming & JSON Response) #

Your existing code saves images to a server directory, but we'll modify it to store the image directly in a database (using MySQL as an example) and generate a unique filename for each upload. First, create a table to store the images:

CREATE TABLE uploaded_images (
    id INT AUTO_INCREMENT PRIMARY KEY,
    filename VARCHAR(255) NOT NULL UNIQUE,
    file_type VARCHAR(100) NOT NULL,
    file_data LONGBLOB NOT NULL,
    uploaded_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

Now, here's the updated PHP code that handles upload, renaming, database insertion, and JSON responses:

<?php
// Database configuration
$dbHost = 'localhost';
$dbName = 'your_database_name';
$dbUser = 'your_db_username';
$dbPass = 'your_db_password';

if (isset($_POST['upload_Btn'])) {
    $uploadedFile = $_FILES['gambar'];
    $response = [];

    // Validate file is an image
    $allowedMimeTypes = ['image/jpeg', 'image/png', 'image/gif', 'image/webp'];
    if (!in_array($uploadedFile['type'], $allowedMimeTypes)) {
        $response = [
            'status' => 'error',
            'message' => 'Invalid file type. Only JPG, PNG, GIF, and WebP are allowed.'
        ];
        sendJsonResponse($response);
    }

    // Generate a unique new filename
    $fileExt = pathinfo($uploadedFile['name'], PATHINFO_EXTENSION);
    $newFilename = uniqid('uploaded_img_', true) . '.' . strtolower($fileExt);

    try {
        // Read image content
        $fileData = file_get_contents($uploadedFile['tmp_name']);

        // Connect to database (using PDO for security)
        $pdo = new PDO(
            "mysql:host=$dbHost;dbname=$dbName;charset=utf8mb4",
            $dbUser,
            $dbPass,
            [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]
        );

        // Insert image into database
        $stmt = $pdo->prepare("
            INSERT INTO uploaded_images (filename, file_type, file_data)
            VALUES (:filename, :file_type, :file_data)
        ");
        $stmt->bindParam(':filename', $newFilename);
        $stmt->bindParam(':file_type', $uploadedFile['type']);
        $stmt->bindParam(':file_data', $fileData, PDO::PARAM_LOB);

        if ($stmt->execute()) {
            $response = [
                'status' => 'success',
                'message' => 'Image uploaded to database successfully',
                'new_filename' => $newFilename
            ];
        } else {
            $response = ['status' => 'error', 'message' => 'Failed to save image to database'];
        }
    } catch (PDOException $e) {
        $response = [
            'status' => 'error',
            'message' => 'Database error: ' . $e->getMessage()
        ];
    } catch (Exception $e) {
        $response = [
            'status' => 'error',
            'message' => 'File read error: ' . $e->getMessage()
        ];
    }

    sendJsonResponse($response);
}

// Helper function to send JSON responses
function sendJsonResponse(array $response): void {
    header('Content-Type: application/json');
    echo json_encode($response);
    exit;
}
?>

Key Improvements & Notes: #

• Security: Uses PDO prepared statements to prevent SQL injection, which is critical when handling user-uploaded data.
• Unique Filenames: uniqid('uploaded_img_', true) generates a highly unique filename (includes microtime) to avoid conflicts.
• Validation: Checks for allowed image MIME types to prevent malicious file uploads.
• Error Handling: Catches database and file read errors to provide meaningful feedback in the JSON response.
• Reusability: The sendJsonResponse helper function avoids code duplication for returning JSON.

内容的提问来源于stack exchange，提问作者quentino97