I try to create a column with computeonchange.

Its works with CREATE TABLE sql command, but if i use ALTER TABLE ADD COLUMN sql command this computeonchange doesn't works.

any reason why?

example:

CREATE TABLE MyStudents ( Name VARCHAR(16) NOT NULL, surname VARCHAR(16))

alter table MyStudents add column fullname Varchar(50) COMPUTECODE { SET {fullname}={Name}_ "?" _{surname}} COMPUTEONCHANGE (Name,surname)

insert into SQLUser.MyStudents (Name, surname) values ('name1',null)

update MyStudents set name = 'name' where name = 'name1'