CREATE TABLE IF NOT EXISTS `Materials` (
  `id` INT NOT NULL AUTO_INCREMENT,
  `name_ar` VARCHAR(150) NOT NULL,
  `code_en` VARCHAR(80) NOT NULL,
  `unit_name` VARCHAR(80) NOT NULL,
  `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` DATETIME NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uq_materials_code_en` (`code_en`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;