Manage multiple category tree in single table in php.

 Create a table with catgory_id,name,parent,sort_order field

<?php
$g_link = mysql_connect( 'localhost', 'root', '');
        mysql_select_db('your_database_name');
       
       
$result = mysql_query("SELECT category_id,name,parent,sort_order FROM category ORDER BY parent,sort_order,name");
 
 
$category = array('categories' => array(),'parent_cats' => array());
 
        while ($row = mysql_fetch_assoc($result)) {
            
            $category['categories'][$row['category_id']] = $row;
            
            $category['parent_cats'][$row['parent']][] = $row['category_id'];
        }
        ?>


/*This function used for show add category (in select box for select parent category) in menu*/ 


<select name="cat">
<option value="0"></option>
<?php

function buildCategory($parent, $category,$name) {
            $html = "";
            if (isset($category['parent_cats'][$parent])) {
                
                foreach ($category['parent_cats'][$parent] as $cat_id) {
                    if (!isset($category['parent_cats'][$cat_id])) {
                        $html .= "<option value='".$category['categories'][$cat_id]['category_id']."'>" . trim($name."->". $category['categories'][$cat_id]['name'],"->") . "</option>";
                    }
                    if (isset($category['parent_cats'][$cat_id])) {
                        $html .= "<option value='".$category['categories'][$cat_id]['category_id']."'>" . trim($name."->".$category['categories'][$cat_id]['name'],"->") . "</option>";
                        $html .= buildCategory($cat_id, $category,trim($name."->".$category['categories'][$cat_id]['name'],"->"));
                        $html .= "</option>";
                    }
                }
                
            }
            return $html;
        }
        echo buildCategory(0, $category ,'');
?>
</select>
<?php
        echo '<br><br>';
        /*--------------------------------end-------------------------------------------------------------------------------------------------------------------------*/

/*This function used for show all categories in menu*/ 


function buildCategory1($parent, $category) {
            $html = "";
            if (isset($category['parent_cats'][$parent])) {
                $html .= "<ul>\n";
                foreach ($category['parent_cats'][$parent] as $cat_id) {
                    if (!isset($category['parent_cats'][$cat_id])) {
                        $html .= "<li>\n  <a href='#'>" .$category['categories'][$cat_id]['name'] . "</a>\n</li> \n";
                    }
                    if (isset($category['parent_cats'][$cat_id])) {
                        $html .= "<li>\n  <a href='#'>" .$category['categories'][$cat_id]['name'] . "</a> \n";
                        $html .= buildCategory1($cat_id, $category);
                        $html .= "</li> \n";
                    }
                }
                $html .= "</ul> \n";
            }
            return $html;
        }
        echo buildCategory1(0, $category);
/*--------------------------------end-------------------------------------------------------------------------------------------------------------------------*/

?>