在CakePHP中手动构建树

$categories = $this->Categories->find('all')->toArray();
$tree = [];
foreach ($categories as $category) {
    if ($category->parent_id == null) {
        $tree[$category->id] = $category;
    } else {
        $tree[$category->parent_id]['children'][$category->id] = $category;
    }
}

function printCategory($category) {
    echo $category->name . "<br>";
    if (isset($category->children)) {
        foreach ($category->children as $child) {
            printCategory($child);
        }
    }
}
foreach ($tree as $category) {
    printCategory($category);
}