private function getOrCreateParameter(Connection $conn, $key, $value)
{
$stmt = $conn->prepare('SELECT id FROM parameter WHERE pkey = ? AND value = ?');
$stmt->execute([$key, $value]);
$identifier = $stmt->fetchColumn();
if (false !== $identifier) {
return $identifier;
}
$stmt = $conn->prepare('INSERT INTO parameter (pkey, value) VALUES (?, ?)');
$stmt->execute([$key, $value]);
return $conn->lastInsertId();
}