<?php
function db() {
    static $pdoconn = null;
    if ($pdoconn === null) {
        $host = '127.0.0.1';
        $db   = 'lamp_app';
        $user = 'lamp_user';
        $pass = '';
        $charset = 'utf8mb4';

        $dsn = "mysql:host=$host;dbname=$db;charset=$charset";
        $options = [
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES   => false,
        ];
        try {
             $pdoconn = new PDO($dsn, $user, $pass, $options);
        } catch (\PDOException $e) {
             throw new \PDOException($e->getMessage(), (int)$e->getCode());
        }
    }
    return $pdoconn;
}

function run_migrations() {
    $pdo = db();
    $migration_files = glob(__DIR__ . '/migrations/*.sql');
    foreach ($migration_files as $file) {
        $sql = file_get_contents($file);
        $pdo->exec($sql);
    }
}

run_migrations();