Re: Tree structure

On Mon, Sep 11, 2000 at 01:27:48PM +0100, Trewern, Ben wrote:
> Anybody know how to make a tree structure using related tables using
> Postgres.  Something like a directory structure is what I'm aiming for.  I'm
> sure there is an easy way but I'm having probs.

I am not quite sure whether this is what you are thinking about:

create table tree ( id int4, parentid int4, data text)

A structure like
a|__b|__c
can be achieved by

insert into tree (id, parentid, data) values (1, NULL, 'a');
insert into tree (id, parentid, data) values (2, 1, 'b');
insert into tree (id, parentid, data) values (3, 1, 'c');


Probably you'll also want to use a sequence for the ids, and to
declare indices on id, parentid etc.

> 
> Any help would be appreciated.
> 
> Ben.


-- 

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Albert Reiner                                   <areiner@tph.tuwien.ac.at>
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