gistfile1.txt

db=# create table object_type (id bigint, parent_id bigint, 
    label text, location text, direct_location boolean);

db=# select * from object_type;
 id  | parent_id |    label    |  location  | direct_location 
-----+-----------+-------------+------------+-----------------
 100 |         0 | book        | main floor | t
 101 |       100 | non-fiction | main floor | f
 102 |       101 | history     | main floor | f
 103 |       102 | ww2         | main floor | t
 104 |       101 | biography   | 2nd floor  | t
 105 |       100 | fiction     | main floor | f