compound key - Mailing list pgsql-sql

Hi,

I have seen the following stucture in AdabasD:
create table AttributeNames (
   id           integer not null,
   name         varchar(200),
   classId      integer not null
);
alter table AttributeNames add primary key (id,classId);

I know, I can't create "compound key" using "alter table", but is there
any way to create one ?

thanx,
Attila