Alter table experimentation

CREATE TABLE user (
	user_id INT(7),
	user_prefix VARCHAR(16),
	name VARCHAR (255),
	created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
	PRIMARY KEY(user_id, user_prefix)
);

DELIMITER $$
CREATE PROCEDURE prepare_data()
BEGIN
  DECLARE i INT DEFAULT 100;

  WHILE i < 10000000 DO
    INSERT INTO user (user_id, user_prefix, name) VALUES (i, i, 'test nad all test because of text');
    SET i = i + 1;
  END WHILE;
END$$
DELIMITER ;

CALL prepare_data();


//UP
ALTER TABLE user DROP PRIMARY KEY, ADD COLUMN `id` INT NOT NULL AUTO_INCREMENT FIRST, ADD PRIMARY KEY (`id`);

//DOWN
ALTER TABLE user DROP PRIMARY KEY, DROP COLUMN `id`, ADD PRIMARY KEY (user_id, user_prefix);