On Mon, Jan 30, 2006 at 03:04:20PM +0200, Gleb Paharenko wrote: > Hello. > > This is not an exact answer on your question, however it could be > interesting for you: > http://dev.mysql.com/tech-resources/articles/hierarchical-data.html
This is a good article. One thing it leaves out of the discussion of the adjacency-lists model is the use of an auxilliary transitive- closure table that makes querying the adjacency-list data efficient and straightforward. (The Celko treatment of the subject referred to in the article covers this.) For some applications where the data set is small and static enough, this can be a good solution too in the right situation, and one that avoids the mathematical hackery of nested sets. --Pete > Jochen Kaechelin wrote: > > I have the following table: > > > > mysql> select * from link_categories; > > +----+-------+-------------+---------------+-----------+---------+ > > | id | level | category_id | category | parent_id | deleted | > > +----+-------+-------------+---------------+-----------+---------+ > > | 1 | 1 | 1000 | Software | 0 | 0 | > > | 2 | 1 | 2000 | Harware | 0 | 0 | > > | 3 | 2 | 1001 | Virenscanner | 1000 | 0 | > > | 4 | 2 | 1003 | Packprogramme | 1000 | 0 | > > | 5 | 3 | 1004 | Linux | 1001 | 0 | > > | 6 | 3 | 1005 | Windows | 1001 | 0 | > > | 7 | 4 | 1006 | Windows XP | 1005 | 0 | > > | 8 | 2 | 1007 | Sniffer | 1000 | 0 | > > | 9 | 4 | 1008 | Debian Woody | 1004 | 0 | > > | 10 | 1 | 100000 | Vermischtes | 0 | 0 | > > +----+-------+-------------+---------------+-----------+---------+ > > 10 rows in set (0.24 sec) > > > > and I want to display a tree like: > > > > Software > > Virenscanner > > Linux > > Debian Woody > > Windows > > Windowsd XP > > Packprogramm > > Sniffer > > Hardware > > Vermischtes > > .... > > > > Can someone give me hint how to build a query? > > > > I run MySQL 4.1.x and 5.0.x and I use PHP. > > > > Thanx. > > > > > -- > For technical support contracts, goto https://order.mysql.com/?ref=ensita > This email is sponsored by Ensita.NET http://www.ensita.net/ > __ ___ ___ ____ __ > / |/ /_ __/ __/ __ \/ / Gleb Paharenko > / /|_/ / // /\ \/ /_/ / /__ [EMAIL PROTECTED] > /_/ /_/\_, /___/\___\_\___/ MySQL AB / Ensita.NET > <___/ www.mysql.com > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] > > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
