modified-preorder-tree-t

Modified preorder tree traversal - determining the "top" when no parent is specified

I'm implementing a Modified preorder tree traversal class for a category tree on a Web site, but I'm having trouble with one scenario. Typically when inserting a new category a top-level parent is specified, whose left value in the tree is used in order to determine where the new category should go in the tree. However, there could be ti...

Storing Composite Patterns (Hierarchical Data) in Database

What are 'best-practices' for saving Composite patterns in a Relational Database? We have been using Modified Preorder Tree Traversal. This is very quick to build the whole tree, but very slow to insert or delete new nodes (all left and right values need to be adjusted). Also querying the children of a node is not easy and very slow. A...

Help on displaying data in colunm PHP MySQL (Modified Preorder Tree Trasversal)

Hello I'm trying to get a multicolumn display (if it can be called so) with the code below here is the result: . Someone can see why These leaves are broken? or tell me please which is better: a catagory table linked to a subcatery one, or an adjacency model list. $stmt = $conn->prepare("SELECT node.idCat_ad ,node.".$cat_name.",(COUNT...

data structure for transversal tree in PHP?

I don't have a background in CS or data structures. I want to make a PHP class that stores a modified preorder transversal tree, for manipulation and syncing with a database. Basically I need to store data like: +-------------+----------------------+-----+-----+ | category_id | name | lft | rgt | +-------------+-------...

Nested Tree Search

Hi, i just followed the answers provided in this question: http://stackoverflow.com/questions/1310649/getting-a-modified-preorder-tree-traversal-model-nested-set-into-a-ul I already built my database and is working properly, printing all the child and parent pages with the correct identation. But, i want to make it like a web search. S...

How to generate a tree view from this result set based on Tree Traversal Algorithm?

I have this table: CREATE TABLE `categories` ( `id` int(11) NOT NULL auto_increment, `category_id` int(11) default NULL, `root_id` int(11) default NULL, `name` varchar(100) collate utf8_unicode_ci NOT NULL, `lft` int(11) NOT NULL, `rht` int(11) NOT NULL, PRIMARY KEY (`id`), KEY `category_id` (`category_id`), KEY `lft`...

How to balance binary tree in PHP without rotating parent?

I will try to make myself as clear as possible. Based from Adjacency List Model: http://articles.sitepoint.com/article/hierarchical-data-database I need a way to balance this tree 0 / \ 1 2 / / \ 3 4 5 \ \ 6 7 to something like: 0 / \ 1 2 / \ / \ 3 ...