Re: Storing a tree
От | Jochem van Dieten |
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Тема | Re: Storing a tree |
Дата | |
Msg-id | 3BEA8DF4.5020802@oli.tudelft.nl обсуждение исходный текст |
Ответ на | Storing a tree (Antonio Fiol Bonnín <fiol@w3ping.com>) |
Список | pgsql-general |
Antonio Fiol Bonnín wrote: > > I would like to store a tree in the database. A tree much like a > directory tree, with un unknown depth. > > However, in my case, the order of the leafs (left to right) is > important. > > I tried to implement the tree as a table: > > CREATE TABLE tree ( father_id int, son_id int ); There may be a better model for your data: the adjacency list model. Take a look at http://www.intelligententerprise.com/001020/celko.shtml If you want to implement it and you need/want to write stored procdures and/or functions to do the most common list manipulation tasks we might be able to work something out. I am a bit short of time at the moment, but I believe it would be great if this stuff ended up in /contrib/ (or is it there already?), and I am willing to invest time in that (but I am leaving on holiday next week). For more code, look at http://www.codebits.com/ntm/ (stored procedures for using this model with MS SQL Server). Jochem
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