-- Invoices table schema (subset for document relationships)
CREATE TABLE `invoices` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) NOT NULL COMMENT 'CMC Invoice Number String',
  `customer_id` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;