How to organize step commenting a La "Habr" in PHP + MySql?

Recursion queries to the database, apparently, is not very suitable.
I used in addition commentID topicID and parentID else, so for him to sample.
Further, PHP is pereimenovaniya in a tree and the whole tree cache in a serialized form.
And recursion is already at the output depending on the layout. with frameworks suggest, alas, can not.

Recursion to help you. Select all comments whose parent_comment_id = 0, and for each of them perform the function recursively get_child_comments($comment_id).
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The structure of the database table is comment_id(int), parent_comment_id(int) comment_text(text) and later.

If you use Yii framework that can be implemented by NestedSet behavior code.google.com/p/yiiext/downloads/detail?name=trees_0.95.zip&can=2&q=

Googling the topic nested sets. All frameworks and ORMах there is a ready implementation. For example in cakephp, doctrine is, and in other types of yii extensions are third-party (or maybe already have built in too).
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Here is a useful links for the trees:

comments broke, here they are:
\rwww.rsdn.ru/article/alg/binstree.xml
\rdoc.prototypes.ru/database/trees/nestedsets/theory/use/
\rbase.vingrad.ru/view/1491-Derevo-katalogov-NESTED-SETS-vlozhennyie-mnozhestva-i-upravlenie-im
\rwww.phpclub.ru/detail/article/db_tree

Recursion in the database (query request) is the death of the project. I get the whole tree in one request (for marshalling topic_id at the time) and build the tree directly in the cycle of data processing.