Getting hierarchy data from self-referencing tables

Question

Let\'s say you have the following table:

items(item_id, item_parent)  

... and it is a self-referencing table - item_parent r

Answer 1

There is a good tech article on the mysql website about hierarchical data in MySql: Managing Hierarchical Data in MySQL - you can find a few detailed solutions with pro and cons there.

Especially the part about "The Nested Set Model" and "Finding the Depth of the Nodes" should be of interest for you.