[company]

You need to do self joins. You can have one comments table but there can be parent_id for each comment.

http://stackoverflow.com/questions/3362038/what-is-self-join... this might help.

[wocp]

Yes, my table structure has a parent_id field. The problem is that I need know the depth, or use recursivity to get all parents.

Using hierarchy and recursivity like this: http://stackoverflow.com/questions/4216875/php-reorder-array...

[company]

http://www.jongales.com/blog/2009/01/27/php-class-for-thread...

see if that helps

[wocp]

I'm going to check out. Thanks!