From: Martijn Tonies
Date: October 19 2004 3:44pm
Subject: Re: Ask for help on a mysql problem
List-Archive: http://lists.mysql.com/mysql/174475
Message-Id: <045f01c4b5f2$860a46b0$0a02a8c0@martijn>
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> > That is ONE way to store a tree structure :-)
>
> > Another would be:
>
> > ITEMS
> > (ItemID INT AUTO_INCREMENT PRIMARY KEY NOT NULL,
> > other stuff)
>
> > ITEM_PARENT
> > (ItemID int,
> >  ParentID int
> > primary key (ItemID, ParentID)
> > )
>
>
> > I prefer the latter.
>
> The latter is not a tree, but a directed graph.

A rooted tree is a special kind of directed graph.

Besides, I wonder if you can fully store a graph in these tables
(with the PK and all)

With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL
Server.
Upscene Productions
http://www.upscene.com