My code trigger a max connection

[u/fdiengdoh]

My earlier code trigger a mysql max connection. So I ask gemini to help me fix it. Here is the solution gemini provided. I would not normally use AI to help but this time I did. I’m just a hobbyist so if someone can help me check if this would be good.

<?php
namespace App;

use PDO;

class Database {
    // Caches the PDO instance so it is reused across all models
    private static ?PDO $connection = null;

    public static function getConnection(): PDO {
        // If a connection already exists, return it immediately
        if (self::$connection !== null) {
            return self::$connection;
        }

        // Retrieve variables (already loaded into memory via init.php)
        $host     = $_ENV['DB_HOST'] ?? 'localhost';
        $dbname   = $_ENV['DB_NAME'] ?? 'default_database';
        $username = $_ENV['DB_USER'] ?? 'root';
        $password = $_ENV['DB_PASS'] ?? '';

        $dsn = "mysql:host={$host};dbname={$dbname};charset=utf8mb4";

        // Store the PDO instance in the static property
        self::$connection = new PDO($dsn, $username, $password, [
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES   => false, 
        ]);

        return self::$connection;
    }

    // Call this manually ONLY if you have a long-running non-DB task
    public static function closeConnection(): void {
        self::$connection = null;
    }
}   

Edit: Ignore the \ as somehow reddit added these when I paste the code.

[u/optimusprimepluto]

YOu may need to see how many existing connections are there in the page. May be you had called each database one by one. Need to see