Amer, It's still worth storing the parentId, because you can easily recreate the fullpath if (when!) your code screws up a set of full paths. You can also write a reliable sanity checker that checks the full path of all the nodes in the table based on the parentids.
Also, to locate multiple children of a node, it's a more efficient query to use "where parentid = x", rather than "where fullpath like '1/2/3/4/%'" All the best, Andy > Yes, excellent idea. It's the classic 'linked list' from my old Pascal > days. While playing with it I realized that you only have to save the > ID, Name and the FullPath (parents) data. For example, using Andy's > data: > > ID | Name | FullPath > -------------------- > 1 | Bob | 0 > 2 | John | 0/1 > 3 | Elm | 0/1 > 4 | Sue | 0/1/2 > 5 | Dave | 0/1/2/4 > 6 | Fred | 0/1/2/4/5 > > The FullPath doesn't need the the 'leaf' or bottom node - it can be > derived (it's the ID). Using a 'split' function on the FullPath data you > can pull out the individual parents. > -- > /* All outgoing email scanned by Norton Antivirus 2002 */ > Amer Neely, Softouch Information Services > W: www.softouch.on.ca > E: [EMAIL PROTECTED] > V: 519.438.5887 > Perl | PHP | MySQL | CGI programming for all data entry forms. > "We make web sites work!" > > > --------------------------------------------------------------------- > Before posting, please check: > http://www.mysql.com/manual.php (the manual) > http://lists.mysql.com/ (the list archive) > > To request this thread, e-mail <[EMAIL PROTECTED]> > To unsubscribe, e-mail > <[EMAIL PROTECTED]> > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > > --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
