MySQL database integration issues with Telegram bot webhook

Other Questions Telegram bot
1

I’m building a Telegram bot for my cafe to handle table bookings and show daily specials. The bot runs on Heroku with PHP and connects to a MySQL database hosted elsewhere. Everything works perfectly until I add the database connection code.

<?php
header('Content-Type: application/json');
$input = file_get_contents("php://input");
$webhook_data = json_decode($input, true);

$connection = mysqli_connect('host', 'user', 'pass', 'database');
$sql = "SELECT * FROM daily_specials ORDER BY position ASC" or die("Query failed: " . mysqli_error($connection));
$query_result = mysqli_query($connection, $sql);
$data_array = array();
while ($record = mysqli_fetch_array($query_result, MYSQLI_ASSOC)) {
    $data_array[] = array(
        'category' => $record['CATEGORY'],
        'dish_name' => $record['DISH']
    );
}
$daily_menu = json_encode($data_array);

$msg = isset($webhook_data['message']) ? $webhook_data['message'] : "";
$msg_id = isset($msg['message_id']) ? $msg['message_id'] : "";
$chat_id = isset($msg['chat']['id']) ? $msg['chat']['id'] : "";
$first_name = isset($msg['chat']['first_name']) ? $msg['chat']['first_name'] : "";
$last_name = isset($msg['chat']['last_name']) ? $msg['chat']['last_name'] : "";
$user_name = isset($msg['chat']['username']) ? $msg['chat']['username'] : "";
$timestamp = isset($msg['date']) ? $msg['date'] : "";
$user_text = isset($msg['text']) ? $msg['text'] : "";
$user_text = trim($user_text);
$user_text = strtolower($user_text);
$today = date('Y-m-d');
$bot_reply = '';
$menu_data = $record['schedule'];

if(strpos($user_text, "/start") === 0 || $user_text=="hello")
{
    $bot_reply = "Hello $first_name $last_name, welcome to our Cafe Bot! Type 'booking' to reserve a table or 'specials' to see today's menu!";
}
elseif($user_text=="booking")
{
    $bot_reply = "How many people for your reservation on $today?";
}
elseif($user_text=="specials")
{
    $bot_reply = "Today's specials: $daily_menu";
}
else
{
    $bot_reply = "Sorry, I don't understand that command!";
}

$params = array('chat_id' => $chat_id, "text" => $bot_reply);
$params["method"] = "sendMessage";
echo json_encode($params);
?>

When I remove all the MySQL code, the bot responds normally. But with the database queries included, it stops working completely. Can someone help me figure out what’s wrong? Is it even possible to use MySQL databases with Telegram bots like this?

2

Run heroku logs --tail to see what’s actually breaking. Usually it’s a connection timeout or bad credentials. That $menu_data = $record['schedule'] line doesn’t make sense either - you’re already looping through records above it. MySQL works fine with Telegram bots, but Heroku’s free tier will kill connections that take too long.

3

Your database connection is probably timing out or failing silently. I ran into the same thing with my restaurant bot - turns out Heroku’s ephemeral filesystem and rotating IPs were screwing with connections. Your MySQL host might be blocking Heroku’s changing IP addresses or you’re hitting connection limits. Wrap your database stuff in try-catch blocks and log the errors so you can see what’s breaking. Also, don’t run database queries inside the webhook response - Telegram only gives you 30 seconds. I switched to caching my daily specials in a local file that updates periodically instead of hitting the database every time someone uses the bot. Way more responsive and no more timeouts.

4

Same exact issue when I built my customer support bot. Your or die() is in the wrong spot - put it after mysqli_query(), not after defining the SQL string. You’re also not checking if the connection worked before running queries. Add if (!$connection) { error_log('Database connection failed: ' . mysqli_connect_error()); return; } right after mysqli_connect. Check if your Heroku app has the right environment variables for database credentials and if your MySQL host allows Heroku IP connections. I’d add error logging to all your database operations so you can see what’s breaking in the Heroku logs. Also watch out for webhook timeouts if your queries take too long.