01_data_definitions.sql

USE intro_test;

CREATE TABLE `employees` (
  `id` int NOT NULL AUTO_INCREMENT,
  `first_name` varchar(50) DEFAULT NULL,
  `last_name` varchar(50) DEFAULT NULL,
  PRIMARY KEY (`id`)
);

CREATE TABLE categories (
	id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(50) NOT NULL
);

CREATE TABLE `products`(
	`id` INT PRIMARY KEY AUTO_INCREMENT,
    `name` VARCHAR(50) NOT NULL,
    `category_id` INT NOT NULL
);

INSERT INTO `employees` VALUES 
(5, 'SQL', 'Inserted'),
(6, "Double", "Quotes"),
(7, "Ruin", 'AI');

SELECT *
FROM employees;

ALTER TABLE employees
ADD COLUMN middle_name VARCHAR(50);

ALTER TABLE products
ADD CONSTRAINT fk_cataegory_id
FOREIGN KEY (category_id) REFERENCES categories(id);

SELECT *
FROM categories;

ALTER TABLE employees
MODIFY COLUMN middle_name VARCHAR(100);