public static function exists($force_create_table=null) {
		$sql = self::$sql;
		$sql::$logger->deactivate();
		try {
			$sql->query("SELECT 1 FROM udata LIMIT 1");
			$sql::$logger->activate();
			if ($force_create_table) {
				self::drop();
				self::$logger->info("Zapmin: Recreating tables.");
				return false;
			}
			return true;
		} catch (SQLError $e) {
		}
		$sql::$logger->activate();
		return false;
	}