dasposchi-de/core/db.php

<?php
/**
 * Datenbank-Verbindung (SQLite PDO Singleton)
 */

require_once __DIR__ . '/../config/config.php';

function db(): PDO
{
    static $pdo = null;
    if ($pdo === null) {
        $pdo = new PDO('sqlite:' . DB_PATH, null, null, [
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES   => false,
        ]);
        $pdo->exec('PRAGMA journal_mode=WAL');
        $pdo->exec('PRAGMA foreign_keys=ON');
    }
    return $pdo;
}