Re: trees in MySQL

The difficulty you are being confronting could be alleviated by using an XML data model (meaning non relational). Of course, I don't know about your requirements, but it could be a direction worth investigating. I use the php_xslt.dll (sablotron) extension, which I find works quite pleasantly. Ignatius ____________________________________________ ----- Original Message ----- From: "José Moreira" <jmoreira@e-terno.net> To: "Php-Db (Correio electrónico)" <php-db@lists.php.net> Sent: Thursday, December 19, 2002 11:45 AM Subject: [PHP-DB] trees in MySQL > hello im implementing a portal and im choosing between the 'Nested Set' and > 'Adjacency Lists tree' models. > > <http://users.starpower.net/rjhalljr/Serve/MySQL/traer.html> > > > im perfectly aware of the 'Adjacency Lists tree' model how-to and I am > studying the 'Nested Set', example follows : > > CREATE TABLE LanguageTree ( > > Language VARCHAR(255) PRIMARY KEY > , Parent VARCHAR(255) > , Lft LONG > , Rgt LONG > , INDEX idxLft (Lft) > , INDEX idxRgt (Rgt) > ) Comment = "Related languages"; > > > A[1 12] > / \ > / \ > B[2 3] C[4 11] > / \ > / \ > D[5 8] F[9 10] > | > E[6 7] > > > my doubt is that if i want to insert a new node, for example 'G' under > 'A' > > A[1 12] > / | \ > / \ > B[2 3] G[] C[4 11] > / \ > / \ > D[5 8] F[9 10] > | > E[6 7] > > > i have? to update almost every left,righ fields after that node, resulting > in a website performance downgrade .... > > > help? even if thjats the only way, how can i do it? perhaps im getting it > wrong ... > > > best regards > > > José Moreira > TEGOPI S.A. > http://www.tegopi.pt > > > > > > > > > > -- > PHP Database Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php