geograsim/App/php/config/db.php

<?php
/**
 * GeoGraSim — Database Connection (PDO)
 */

require_once __DIR__ . '/app.php';

function getDB(): PDO {
    static $pdo = null;
    if ($pdo === null) {
        $dsn = sprintf('mysql:host=%s;port=%s;dbname=%s;charset=utf8mb4', DB_HOST, DB_PORT, DB_NAME);
        $pdo = new PDO($dsn, DB_USER, DB_PASS, [
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES   => false,
            PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8mb4 COLLATE utf8mb4_unicode_ci",
        ]);
    }
    return $pdo;
}