If the tree isn’t too large, you can simply build the tree in PHP using some clever references.
$nodeList = array();
$tree = array();
$query = mysql_query("SELECT category_id, name, parent FROM categories ORDER BY parent");
while($row = mysql_fetch_assoc($query)){
$nodeList[$row['category_id']] = array_merge($row, array('children' => array()));
}
mysql_free_result($query);
foreach ($nodeList as $nodeId => &$node) {
if (!$node['parent'] || !array_key_exists($node['parent'], $nodeList)) {
$tree[] = &$node;
} else {
$nodeList[$node['parent']]['children'][] = &$node;
}
}
unset($node);
unset($nodeList);
This will give you the tree structure in $tree
with the children in the respective children
-slot.
We’ve done this with fairly large trees ( >> 1000 items) and it’s very stable and a lot faster than doing recursive queries in MySQL.