CREATE TABLE IF NOT EXISTS `discussions` ( `id` INT AUTO_INCREMENT PRIMARY KEY, `community_id` INT NOT NULL, `user_id` INT NOT NULL, `title` VARCHAR(255) NOT NULL, `content` TEXT NOT NULL, `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP, FOREIGN KEY (`community_id`) REFERENCES `communities`(`id`), FOREIGN KEY (`user_id`) REFERENCES `users`(`id`) ); CREATE TABLE IF NOT EXISTS `discussion_replies` ( `id` INT AUTO_INCREMENT PRIMARY KEY, `discussion_id` INT NOT NULL, `user_id` INT NOT NULL, `content` TEXT NOT NULL, `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP, FOREIGN KEY (`discussion_id`) REFERENCES `discussions`(`id`), FOREIGN KEY (`user_id`) REFERENCES `users`(`id`) );