CREATE TABLE t_set (id INT NOT NULL PRIMARY KEY, value SET('one', 'two'));

INSERT
INTO    t_set
VALUES  (1, 1);

SELECT  *
FROM    t_set;


id    value
----  ------
   1  one

UPDATE  t_set
SET     value = 0;

SELECT  *
FROM    t_set;

id    value
----  ------
   1