How do I aggregate results from an Adjacency list using PHP's SPL
- by Stephen J. Fuhry
I've tried using nested sets, and they become very difficult to maintain when dealing with multiple trees and lots of other complications.. I'd like to give PHP's SPL library a stab at this (btw, we are PHP 5.3, MySQL 5.1).
Given two datasets:
The Groups:
+-------+--------+---------------------+---------------+
| id | parent | Category Name | child_key |
+-------+--------+---------------------+---------------+
| 11133 | 7707 | Really Cool Products| 47054 |
| 7709 | 7708 | 24" Monitors | 57910 |
| 7713 | 7710 | Hot Tubs | 35585 |
| 7716 | 7710 | Hot Dogs | 00395 |
| 11133 | 7707 | Really Cool Products| 66647 |
| 7715 | 7710 | Suction Cups | 08396 |
+-------+--------+---------------------+---------------+
The Items
+------------+------------+-----------+----------+---------+
| child_key | totalprice | totalcost | totalqty | onorder | (jan, feb, mar..)
+------------+------------+-----------+----------+---------+
| 24171 | 10.50 | 20.10 | 200 | 100 |
| 35685 | 10.50 | 20.10 | 200 | 100 |
| 76505 | 10.50 | 20.10 | 200 | 100 |
| 04365 | 10.50 | 20.10 | 200 | 100 |
| 01975 | 10.50 | 20.10 | 200 | 100 |
| 12150 | 10.50 | 20.10 | 200 | 100 |
| 40060 | 10.50 | 20.10 | 200 | 100 |
| 08396 | 10.50 | 20.10 | 200 | 100 |
+------------+------------+-----------+----------+---------+
The figures are actually much more complicated than this (I am actually aggregating a variable amount of months or years over the past 15yrs, so there may need to be 20 columns of aggregated results).
I have been trying to figure out RecursiveIterator and IteratorAggregate, but I am having a difficult time finding real world examples that are generic enough to really wrap my head around these classes.
Can someone give me a head start?
