CREATE TABLE students (
  id INT AUTO_INCREMENT KEY,
  name VARCHAR(50) NOT NULL,
  email VARCHAR(100) UNIQUE NOT NULL
);

INSERT INTO students (name,email) VALUES
('Рамазан','ebalkozu@mail.ru'),
('Роман','popapisya@mail.ru'),
('Артемий','piskatryas@mail.ru');   

UPDATE students SET email = 'ASDASDADD@mail.ru' WHERE id = 1;

ALTER TABLE students ADD COLUMN phone_number VARCHAR(11);

UPDATE students SET phone_number = '88005553535' WHERE phone_number IS NULL;

DELETE FROM students WHERE id = 1;

INSERT INTO students (id,name,email) VALUES
(1,'Александр','lychiy@mail.ru');

SELECT * FROM students;