BEGIN;
alter table company add column suppl_custid varchar(10);
update company set suppl_custid = '' where suppl_custid IS NULL;
alter table company alter column suppl_custid set NOT NULL;
alter table company alter column suppl_custid set default '';

alter table company add column suppl_login varchar(15);
update company set suppl_login = '' where suppl_login IS NULL;
alter table company alter column suppl_login set NOT NULL;
alter table company alter column suppl_login set default '';

alter table company add column suppl_password varchar(15);
update company set suppl_password = '' where suppl_password IS NULL;
alter table company alter column suppl_password set NOT NULL;
alter table company alter column suppl_password set default '';

COMMIT;

