title: PHP recursive function to retrieve all children of a category
body: <p>I would like to write a recursive PHP function to retrive all the children for the specified category. I tried the one described <a href="https://stackoverflow.com/questions/2398402/recursive-function-to-get-all-the-child-categories">here</a> but it didn't output what I have expected. </p>
  
  <p>My categories table looks like this:</p>
  
  <pre><code>CREATE TABLE `categories` (
   `category_id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,
   `category_name` varchar(256) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
   `category_slug` varchar(256) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
   `category_parent` smallint(5) unsigned NOT NULL DEFAULT '0',
   `category_description_ro` text CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
   `category_description_en` text CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
   PRIMARY KEY (`category_id`)
  ) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=latin1
  </code></pre>
  
  <p>Bellow is an example of data in the table:</p>
  
  <pre><code>category id | category name | category_parent
  
  1            Categoria 1            0        
  2            Categoria 2            0        
  3            Categoria 3            0        
  4            Categoria 1.1          1        
  5            Categoria 1.2          1        
  6            Categoria 1.3          1        
  7            Categoria 1.1.2        4 
  </code></pre>
  
  <p>Thanks.</p>