CREATE TABLE `billing` (
  
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `identifier` varchar(255) NOT NULL,
  `sender` varchar(255) NOT NULL,
  `target_type` varchar(50) NOT NULL,
  `target` varchar(255) NOT NULL,
  `label` varchar(255) NOT NULL,
  `amount` int(11) NOT NULL,
  
  PRIMARY KEY (`id`)
);