如何格式化动态数组进行JSON编码？谷歌地图坐标JSON构建求助

Got it, let's adjust your PHP code to generate the exact JSON structure you need for Google Maps coordinates. Here's the complete, working version with explanations:

<?php
try {
    $conn = new PDO('mysql:host=localhost;dbname=dining', 'root', 'mypasswordhere');
    // Enable exception handling for query errors (not just connection issues)
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $qry = "SELECT dining_lat, dining_long FROM dining_listings";
    $getData = $conn->query($qry);
    
    $restaurants = [];
    // Loop through each database row to build your lat/lng objects
    foreach ($getData->fetchAll(PDO::FETCH_ASSOC) as $row) {
        $restaurants[] = [
            'lat' => (float)$row['dining_lat'], // Cast to float to ensure numeric JSON values
            'lng' => (float)$row['dining_long']
        ];
    }

    // Build the final JSON structure and encode it
    $jsonOutput = json_encode(['restaurants' => $restaurants]);
    
    // Set the correct HTTP header for JSON responses (critical for API clients)
    header('Content-Type: application/json');
    echo $jsonOutput;

} catch (PDOException $e) {
    // Handle errors gracefully with a JSON error response
    header('HTTP/1.1 500 Internal Server Error');
    echo json_encode(['error' => $e->getMessage()]);
    exit;
}
?>

Key Details: #

• PDO Error Mode: Added PDO::ERRMODE_EXCEPTION so any query failures (not just connection issues) are caught in your try/catch block, making debugging easier.
• Data Casting: Converting dining_lat and dining_long to floats ensures they appear as numeric values in the JSON (not quoted strings), which matches your desired format.
• Structure Matching: We wrap the array of lat/lng objects inside a parent array with the restaurants key—this is exactly the structure you specified.
• Proper Headers: Setting Content-Type: application/json tells browsers or API clients that the response is JSON, which is essential for Google Maps to parse it correctly.

Example Output: #

If your database has the coordinates you listed, this code will output:

{"restaurants":[{"lat":-84.9834,"lng":85.8374},{"lat":-84.8378,"lng":85.8374},{"lat":-84.7384,"lng":85.3784}]}

内容的提问来源于stack exchange，提问作者Hayden