CREATE TABLE IF NOT EXISTS `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(50) NOT NULL,
  `password` varchar(255) NOT NULL,
  `email` varchar(100) NOT NULL,
  `created_at` datetime DEFAULT CURRENT_TIMESTAMP,
  `school_id` INT,
  `role` VARCHAR(255) NOT NULL DEFAULT 'teacher',
  PRIMARY KEY (`id`),
  UNIQUE KEY `username` (`username`),
  CONSTRAINT `fk_users_school_id` FOREIGN KEY (`school_id`) REFERENCES `schools`(`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;