def insert_settings(defaults): """Insert the given setting if they don't exist yet. XXX: Does not include any support for MultiSetting. This approach won't work for that. We'll need to use a migration script. :type defaults: list :param defaults: Key and value pairs :rtype: list :returns: Any settings that have just been created. """ inserted = [] try: settings_query = DBSession.query(Setting.key)\ .filter(Setting.key.in_([key for key, value in defaults])) existing_settings = set(x[0] for x in settings_query) except ProgrammingError: # If we are running paster setup-app on a fresh database with a # plugin which tries to use this function every time the # Environment.loaded event fires, the settings table will not # exist and this exception will be thrown, but its safe to ignore. # The settings will be created the next time the event fires, # which will likely be the first time the app server starts up. return inserted for key, value in defaults: if key in existing_settings: continue transaction = DBSession.begin_nested() try: s = Setting(key, value) DBSession.add(s) transaction.commit() inserted.append(s) except IntegrityError: transaction.rollback() if inserted: DBSession.commit() return inserted