Ian Buzer wrote: >> You could set your table up in a "modified preorder tree traversal", so >> each node has a "LFT" and "RGT" numeric value. I've done this in several >> instances and it works great. > > Hey, thanks Dov, that's lovely. > > As far as I understand it so far, it does have the snag that if you make a > change near the top of the hierachy, a whole lot of data below has to be > updated.
Depends on what type of change. If you don't use sequential nubers for left and right but increment by a thousand initially you can easily insert items without changing the rest. I don't know which term to Google for, but last year Joe Celko indicated this would be covered by his new book "Trees and Hierarchies in SQL for Smarties". Jochem ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Special thanks to the CF Community Suite Silver Sponsor - New Atlanta http://www.newatlanta.com Message: http://www.houseoffusion.com/lists.cfm/link=i:4:188654 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
