ALTER TABLE `price_list_items`
  ADD COLUMN `service_type` VARCHAR(30) NOT NULL DEFAULT 'broadcast' AFTER `name`,
  ADD COLUMN `unit` VARCHAR(30) NOT NULL DEFAULT 'emitiranje' AFTER `service_type`,
  MODIFY COLUMN `duration_from_seconds` INT UNSIGNED NULL,
  MODIFY COLUMN `duration_to_seconds` INT UNSIGNED NULL,
  MODIFY COLUMN `time_from` TIME NULL,
  MODIFY COLUMN `time_to` TIME NULL;