A small library based on the technique outlined here: http://ferdychristant.com/blog//archive/DOMM-7QJPM7

Stores & retrieves parent/child data without having to do recursive db hits. Comments in library file are pretty self-explanatory.

Output can either come in the form:

Record 1
Record 1.1
Record 1.2
Record 1.2.3
Record 2
...

or as a multi-dimensional array

https://github.com/jrmadsen67/mahana-hierarchy

All comments or recommendations welcomed.

Often threatened, rarely made good on…

a short tut on how to use this to create nested comments, etc without needing recursive functions:

http://codebyjeff.com/blog/2012/10/nested-data-with-mahana-hierarchy-library

library has a couple of additions to make it a little easier to work with, as well

I’ll use this library in a recent project for a welfare organization. Thanks a lot!

I had a little time this morning, I took the opportunity to have a look there as I had said.
However, I have a question.
After multiple answers, I get this lineage:

Why not just (less in db):

Otherwise, it happens when you post the 100000th post?

For forums and CMS’s you can try this too (I’m not really sure about the performance, but I guess it’s good since they use it in Prestashop):

http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/

Noobigniter - 22 October 2012 11:11 AM

I had a little time this morning, I took the opportunity to have a look there as I had said.
However, I have a question.
After multiple answers, I get this lineage:

00001-00002-00003-00006-00011-00012-00013-00014-00015-00016-00017 

Why not just (less in db):

1-2-3-5-11-12-13-14-15-16-17 

Otherwise, it happens when you post the 100000th post?

 

the trick is to do a simple orderby on the lineage - if you don’t pad, you get

1-11-111-2-...

NeoArc - 22 October 2012 10:44 AM

I’ll use this library in a recent project for a welfare organization. Thanks a lot!

cool! let me know if you run into difficulties or have suggestions after using it

A suggestion, I do not know if is is one, but I immediately changed one little thing in the class, so you can use it on several tables (pages, category, comments, etc ...)

I commented :

and added this

Then it only remains to choose the table to use.

It’s not much, but pretty handy.

Otherwise, nothing to report at this time.

PS: thank you

yes, not a bad idea. I think I might actually add a full $config in instead, so later we can config other things as well (like padding size, for example)

glad it’s working out

Me again ^^
I noticed that it is easy to work on 1 table, however, and after creating a function like

, working on several tables becomes “dangerous “, even impossible if multiple identical fields in different tables (ie: id, user_id,..)
So I have to abandon much of the library, unfortunately.
I’ll just use the system of “lineage” on insert, which I had not thought of.

yes, i think that’s why a config will be the better way to go.

I’ll have a look at adding that today if I get time

Couple quick updates:

1) now uses $config and an initialize method, so you can use multiple instances in site or even same page

2) composer package available: https://packagist.org/packages/jrmadsen67/mahana-hierarchy

Careful - I’ve renamed $_db to $db & $_table to $table as you can now pass these as $config keys

And a couple more

(I’m actively using this in a site I’m working on, so adding things as I find I need them)

get_ancestors($id, $remove_this = false)

Returns an array of all the ancestors of the given record. Second parameter will leave out the requesting record or not

get_parent($id)

Returns an row array of the parent of the given record.