text: CREATE TABLE `yii2basic`.`book` (
  	`id` INT AUTO_INCREMENT PRIMARY KEY,
  	`title` VARCHAR(63) NOT NULL,
  	`authors` VARCHAR(63) NOT NULL,
  	-- `authors` INT REFERENCES `yii2basic`.`authors`(ID),
  	`published` DATE NULL,
  	`created` TIMESTAMP NOT NULL
  		DEFAULT CURRENT_TIMESTAMP);
  
  -- CREATE TABLE `yii2basic`.`author` (
  -- 	`id` INT AUTO_INCREMENT PRIMARY KEY,
  -- 	`first_name` VARCHAR(45) NOT NULL,
  -- 	`last_name` VARCHAR(45) NOT NULL);
  
  -- ALTER TABLE `yii2basic`.`book` 
  -- ADD CONSTRAINT `fk_book`
  -- 	FOREIGN KEY (`authors`)
  -- 	REFERENCES `yii2basic`.`author` (`id`);
  