我在本地服务器 (Xampp) 上的 PHP 代码有预期的结果，但在在线服务器上却没有

Question

Good afternoon people.

I created some functions in php / MySQL that returns a json object, As you can see in the code below.

File tweets.php (Class)

    <?php
class Tweets {
    private $conn;
    private $table_name = 'tweets';

    public $id;
    public $text;
    public $created_at;

    // Constructor
    public function __construct($db) {
        $this->conn = $db;
    }

    public function readAll() {
        $query = "SELECT * FROM " . $this->table_name . " ORDER BY created_at ASC";

        $stmt = $this->conn->prepare($query);

        $stmt->execute();

        return $stmt;
    }

    public function create() {
        $query = "INSERT INTO " . $this->table_name . " SET tweet_id = :tweet_id, text = :text, created_at = :created_at";

        $stmt = $this->conn->prepare($query);

        $this->tweet_id = htmlspecialchars(strip_tags($this->tweet_id));
        $this->text = htmlspecialchars(strip_tags($this->text));
        $this->created_at = htmlspecialchars(strip_tags($this->created_at));

        $stmt->bindParam(':tweet_id', $this->tweet_id);
        $stmt->bindParam(':text', $this->text);
        $stmt->bindParam(':created_at', $this->created_at);

        if($stmt->execute()) {
            return $this->conn->lastInsertId();
        }

        return false;
    }

    public function delete() {
        $query = "DELETE FROM " . $this->table_name . " WHERE id = ?";

        $stmt = $this->conn->prepare($query);

        $this->id = htmlspecialchars(strip_tags($this->id));

        $stmt->bindParam(1, $this->id);

        if($stmt->execute()) {
            return true;
        }

        return false;
    }

    public function deleteAll() {
        $query = "DELETE FROM " . $this->table_name;

        $stmt = $this->conn->prepare($query);

        if($stmt->execute()) {
            return true;
        }

        return false;
    }

    public function search($keywords, $start, $end){
        $query = "SELECT * FROM " . $this->table_name . " WHERE text LIKE ? ORDER BY id ASC LIMIT ?, ?";
    
        $stmt = $this->conn->prepare($query);
    
        $keywords=htmlspecialchars(strip_tags($keywords));
        $keywords = "%{$keywords}%";
    
        $stmt->bindParam(1, $keywords);
        $stmt->bindParam(2, $start, PDO::PARAM_INT);
        $stmt->bindParam(3, $end, PDO::PARAM_INT);
    
        $stmt->execute();
    
        return $stmt;
    }

    public function count(){
        $query = "SELECT COUNT(*) as total_rows FROM " . $this->table_name . "";
    
        $stmt = $this->conn->prepare( $query );
        $stmt->execute();
        $row = $stmt->fetch(PDO::FETCH_ASSOC);
    
        return $row['total_rows'];
    }
}
?>

File getTweets.php

<?php
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json");
header("Access-Control-Allow-Methods: GET");
header("Access-Control-Max-Age: 3600");
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

require_once '../config/config.php';
include_once '../config/database.php';

include_once '../objects/tweets.php';

$database = new Database();
$db = $database->getConnection();

$tweets = new Tweets($db);

$keywords = isset($_GET["s"]) ? $_GET["s"] : "";
$start = isset($_GET['start']) ? $_GET['start'] : '';
$end = isset($_GET['end']) ? $_GET['end'] : '';

$stmt = $tweets->search($keywords, $start, $end);
$num = $stmt->rowCount();

if($num > 0) {
    $tweet_arr = array();

    while($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
        extract($row);

        $tweet_item = array(
            "text" => $text,
        );

        array_push($tweet_arr, $tweet_item);
    }

    http_response_code(200);
  
    echo json_encode($tweet_arr);
} else {
     http_response_code(404);
  
     echo json_encode(
         array("message" => "Nao foi achada nenhuma promoção.")
     );
}
?>

The functions work perfectly on my local web server (Xampp), but when I upload to the final web server (Online), I have the response status 200 OK but without any json object.

As you can see in the images below, the first is the response from the local server and the second from online. What could be happening?

PrintScreen Postman - local

PrintScreen Postman - online

Answer 1

There could be errors that aren't being displayed, try adding the following code to the top of 'getTweets.php' and see if you get any PHP Warnings/Errors

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

Answer 2

据我所知，您没有将相同的参数传递给 Postman 中的在线测试，您缺少“开始”和“结束”，而且您似乎没有在 search() 方法中处理它们。

Answer 3

The chances are that you have a different default charset on the live sever vs local

Check that you connection string contains the charset

mysql:host=HOSTNAME;dbname=DBNAME;charset=utf8;

Answer 4

After reading the PHP manual a lot I decided to create a function to handle the result. I did these two functions below, I hope it helps other people with the same problem that I had.

function safe_json_encode($value){
    if (version_compare(PHP_VERSION, '5.4.0') >= 0) {
        $encoded = json_encode($value, JSON_PRETTY_PRINT);
    } else {
        $encoded = json_encode($value);
    }
    switch (json_last_error()) {
        case JSON_ERROR_NONE:
            return $encoded;
        case JSON_ERROR_DEPTH:
            return 'Maximum stack depth exceeded';
        case JSON_ERROR_STATE_MISMATCH:
            return 'Underflow or the modes mismatch';
        case JSON_ERROR_CTRL_CHAR:
            return 'Unexpected control character found';
        case JSON_ERROR_SYNTAX:
            return 'Syntax error, malformed JSON';
        case JSON_ERROR_UTF8:
            $clean = utf8ize($value);
            return safe_json_encode($clean);
        default:
            return 'Unknown error';
    }
}
    
    
function utf8ize($mixed) {
    if (is_array($mixed)) {
        foreach ($mixed as $key => $value) {
            $mixed[$key] = utf8ize($value);
        }
    } else if (is_string ($mixed)) {
        return utf8_encode($mixed);
    }
    return $mixed;
}

Call:

safe_json_encode($tweet_arr);