Saluton,
this is easy:
On Fri, Oct 20, 2000 at 06:48:54PM +0800, pgsql-sql wrote:
...
> NODE1
> + --- NODE1_1
> + --- NODE1_2
> | + --- NODE1_2_1
> + --- NODE1_3
create table n (id int4, parent int4, data text);
insert into n (id, data) values (1, 'node 1');
insert into n (id, parent, data) values (2, 1, 'node 1.1');
insert into n (id, parent, data) values (3, 1, 'node 1.2');
insert into n (id, parent, data) values (4, 3, 'node 1.2.1');
insert into n (id, parent, data) values (5, 1, 'node 1.3');
(you will probably want to use a serial for id, etc.)
The idea is to store each node in a row, and to store both the row's
id and the id of the parent node in it. When there is no parent node
(your node NODE_1), parent is NULLL.
HTH,
Albert.
--
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Albert Reiner <areiner@tph.tuwien.ac.at>
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