PHP + MySQL implementation of unlimited classification columns

This article mainly introduces how PHP + MySQL implements the unlimited classification topic, and involves php database query operations and recursive traversal of result sets, for more information about how to implement the unlimited classification topic in PHP + MySQL, see the following example. We will share this with you for your reference. The details are as follows:

A simple, clear, and simple unlimited classification example with indentation. you only need to query the data table once and recursively traverse the result set, to enable the column indent display in php, refer.

$ SQL = 'select * from cat order by cat_id desc '; $ list = $ db-> getAll ($ SQL); $ list = getLevelCat ($ list ); function getLevelCat ($ catlist, $ parent_id = '0', $ html = '', $ level = '0') {$ arr = array (); foreach ($ catlist as $ val) {if ($ val ['parent _ id'] ==$ parent_id) {$ val ['HTML '] = str_repeat ($ html, $ level); $ val ['level'] = $ level; $ arr [] = $ val; $ arr = array_merge ($ arr, getLevelCat ($ catlist, $ val ['cat _ id'], $ html, $ level + 1) ;}return $ arr ;}

Implementation:

Just a few lines of code, clear and easy to use.

I hope this article will help you with PHP programming.