Category Sub Category recursive function, To display category sub category on page.
Table for Category:
CREATE TABLE IF NOT EXISTS `category` (
`cid` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(255) NOT NULL,
`parent` int(11) NOT NULL,
PRIMARY KEY (`cid`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;
Insert some dummy records. Parent columns with zero value denotes its the base/root category.
Example
INSERT INTO `category` (`cid`, `name`, `parent`) VALUES
(1, 'Hardware', 0),
(2, 'Software', 0),
(3, 'Movies', 0),
(4, 'Clothes', 0),
(5, 'Printers', 1),
(6, 'Monitors', 1),
(7, 'Inkjet printers', 5),
(8, 'Laserjet Printers', 5);
Creating category Tree using recursion
function fetchCategoryTree($parent = 0, $spacing = '', $user_tree_array = '') {
if (!is_array($user_tree_array))
$user_tree_array = array();
$sql = "SELECT `cid`, `name`, `parent` FROM `category` WHERE 1 AND `parent` = $parent ORDER BY cid ASC";
$query = mysql_query($sql);
if (mysql_num_rows($query) > 0) {
while ($row = mysql_fetch_object($query)) {
$user_tree_array[] = array("id" => $row->cid, "name" => $spacing . $row->name);
$user_tree_array = fetchCategoryTree($row->cid, $spacing . ' ', $user_tree_array);
}
}
return $user_tree_array;
}
Display the category tree in a dropdown list.
<?php
$categoryList = fetchCategoryTree();
?>
<select>
<?php foreach($categoryList as $cl) { ?>
<option value="<?php echo $cl["id"] ?>"><?php echo $cl["name"]; ?></option>
<?php } ?>
</select>
Displaying Category tree in list format
function fetchCategoryTreeList($parent = 0, $user_tree_array = '') {
if (!is_array($user_tree_array))
$user_tree_array = array();
$sql = "SELECT `cid`, `name`, `parent` FROM `category` WHERE 1 AND `parent` = $parent ORDER BY cid ASC";
$query = mysql_query($sql);
if (mysql_num_rows($query) > 0) {
$user_tree_array[] = "<ul>";
while ($row = mysql_fetch_object($query)) {
$user_tree_array[] = "<li>". $row->name."</li>";
$user_tree_array = fetchCategoryTreeList($row->cid, $user_tree_array);
}
$user_tree_array[] = "</ul>";
}
return $user_tree_array;
}
<ul>
<?php
$res = fetchCategoryTreeList();
foreach ($res as $r) {
echo $r;
}
?>
</ul>
