Can all views be updated?

CREATE VIEW emp_basic AS SELECT id, name, salary FROM employees; UPDATE emp_basic SET salary = 75000 WHERE id = 101;

Will this update work?

INSERT INTO emp_basic (id, name, salary) VALUES (110, 'New Emp', 50000);

What happens with updatable view?

DELETE FROM emp_basic WHERE id = 110;

What does this do with updatable view?

CREATE VIEW dept_stats AS SELECT dept_id, COUNT(*) FROM employees GROUP BY dept_id; UPDATE dept_stats SET ...

Will this update work?