init.sql

create table categories (
  id          serial,
  parent_id   int4 references categories (id),
  name        varchar(100),
  primary key (id)
);

insert into categories (name) values ('one'), ('two'), ('three');

insert into categories (parent_id, name) values (1, 'cat'), (1, 'dog'), (1, 'bird'), (3, 'no'), (3, 'yes'), (3, 'maybe'), (8, 'good'), (8, 'bad'), (8, 'evil'), (4, 'diabetes'), (4, 'wilford brimley');