create table organization(
orgid number not null primary key,
ordparent number,
orgname varchar2(40) not null);

alter table organization add constraint fk_parent foriegn key (orgparent) references organization(orgid);

-- start inserts for organizations
insert into organization  ....etc.
-- end inserts for organizations

create table orglevels(
levelid number not null,
levelname varchar2(20) not null);

insert into orglevels values (1,'Sector');
insert into orglevels values (2,'Department');
insert into orglevels values (3,'Division');