How to organize a stepped commenting model a la "Habr" in PHP + MySql?

Question

PHP

The question is, in fact, in the title. What connections in the muscle to use, how to properly organize the output?

Answer 1

Recursion with queries to the database, apparently, is not very suitable.
In addition to commentID and parentID, I also used topicID to make a selection based on it.
Further, in php, this is re-formed into a tree and the entire tree is cached in a serialized form.
And the recursion is already in the output, depending on the layout. with frameworks, alas, I can not tell.

Answer 2

Recursion to help you. Select all comments that have parent_comment_id = 0 and for each of them execute the get_child_comments($comment_id) function recursively.
The structure of the database table is something like this: comment_id(int), parent_comment_id(int), comment_text(text) and further as desired.

Answer 3

If you use the Yii framework, then you can implement it using the NestedSet behavior code.google.com/p/yiiext/downloads/detail?name=trees_0.95.zip&can=2&q=

Answer 4

Google about nested sets. On any frameworks and ORMs there are ready-made implementations. For example, in cakephp, doctrine is, and in others like yii there are third-party extensions (or maybe already built in too).
Here are some useful tree links:

Answer 5

google://hierarchical+structures+in+databases+

Answer 6

the comment ended, here they are :
www.rsdn.ru/article/alg/binstree.xml
doc.prototypes.ru/database/trees/nestedsets/theory/use/base.vingrad.ru/view/1491-Derevo-katalogov-NESTED
-SETS-vlozhennyie-mnozhestva-i-upravlenie-im
www.phpclub.ru/detail/article/db_tree

Answer 7

Recursion in the database (request in a request) is the death of a project. I display the entire tree in one query (ordered by topic_id by time) and build the tree directly in the data processing loop.

Answer 8

It is better to store the entire path (list of parent-id) to the comment, then the tree of comments can be selected with one request (this is how, in my opinion, they do it in LiveJournal).

Answer 9

After all the comments from the database related to the post are received in one request, make up a tree-like php array. In parallel, maintain a linear array, the keys of which are the id of the comment, and the values ​​are links to the elements of the tree. Such a “reference” list is needed in order to simply add nested comments indicating only the parent id and not to search the entire tree where to put a new comment.

Answer 10

forums and comments often use left-right numbering. This greatly increases the cost of adding new nodes:
http://blogs.sitepoint.com/hierarchical-data-database-2/