# How to use find threaded

**URL:** <https://discourse.cakephp.org/t/how-to-use-find-threaded/9414>\
**Category:** Need Help\
**Created:** [June 5, 2021, 11:50am UTC](https://discourse.cakephp.org/t/how-to-use-find-threaded/9414 "2021-06-05T11:50:29Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![magic77](https://avatars.discourse-cdn.com/v4/letter/m/ee59a6/32.png) [@magic77](https://discourse.cakephp.org/u/magic77)\
**Post date:** [June 5, 2021, 11:50am UTC](https://discourse.cakephp.org/t/how-to-use-find-threaded/9414/1 "2021-06-05T11:50:29Z")

</div>

How to link two tables so that I can get the main nodes and their child nodes with find threaded?  
My target is to render a menu like this

```auto
<ul>
    <li class="category">Category 1</li>
       <ul>
          <li class="sub">Subcategory 1</li>
          ...
       </ul>
    <li class="category">Category 2</li>
        <ul>
            <li class="sub">Subcategory 1</li>
            ...
        </ul>
   </li>
</ul>

```

I have created two tables.  
Categories

```auto
CREATE TABLE `categories` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
    `name` varchar(255) DEFAULT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `categories` (`id`, `name`) VALUES (NULL, 'Category 1');
INSERT INTO `categories` (`id`, `name`) VALUES (NULL, 'Category 2');

```

Subcategories

```auto
CREATE TABLE `subcategories` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
    `name` varchar(255) DEFAULT NULL,
    `category_id` INT UNSIGNED NULL DEFAULT NULL
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `subcategories` (`id`, `name`, `category_id`) VALUES (NULL, 'Subcategory 1', 1);
INSERT INTO `subcategories` (`id`, `name`, `category_id`) VALUES (NULL, 'Subcategory 1', 1);
INSERT INTO `subcategories` (`id`, `name`, `category_id`) VALUES (NULL, 'Subcategory 1', 1);
INSERT INTO `subcategories` (`id`, `name`, `category_id`) VALUES (NULL, 'Subcategory 1', 2);
INSERT INTO `subcategories` (`id`, `name`, `category_id`) VALUES (NULL, 'Subcategory 1', 2);

```

My association for these two tables look like

```auto
class CategoriesTable extends Table
{
    public function initialize(array $config)
    {
        $this->belongsTo('Subcategories', [
            'foreignKey' => 'category_id'
        ]);
    }
   ...
}

```

```auto
class SubcategoriesTable extends Table
{
    public function initialize(array $config)
    {
        $this->belongsTo('Categories');
    }
    ...
}

```

When i now output the Result of

```auto
TableRegistry::getTableLocator()->get('Categories')->find('threaded')->toArray();

```

I get the list of Categories but the children nodes are empty as of missing of **parent\_id**.  
According to the definition of CakePHP you should use a **parent\_id** for this. But I am not clear how to use this.  
[https://book.cakephp.org/3/en/orm/retrieving-data-and-resultsets.html#finding-threaded-data](https://book.cakephp.org/3/en/orm/retrieving-data-and-resultsets.html#finding-threaded-data)

I am still CakePHP beginner and maybe somebody can help me with this.

---

<div class="post-metadata">

**Author:** ![Zuluru](https://yyz1.discourse-cdn.com/flex029/user_avatar/discourse.cakephp.org/zuluru/32/1230_2.png) [@Zuluru](https://discourse.cakephp.org/u/Zuluru)\
**Post date:** [June 5, 2021, 3:13pm UTC](https://discourse.cakephp.org/t/how-to-use-find-threaded/9414/2 "2021-06-05T15:13:40Z")

</div>

I think that what you want is not `find('threaded')`, but rather `find()->contain(['Subcategories'])`. Threaded is, as far as I can tell, for when the related records are all in the same table, e.g. a post has replies which are also posts, which in turn have replies which are also posts, etc.

---

<div class="post-metadata">

**Author:** ![magic77](https://avatars.discourse-cdn.com/v4/letter/m/ee59a6/32.png) [@magic77](https://discourse.cakephp.org/u/magic77)\
**Post date:** [June 5, 2021, 4:11pm UTC](https://discourse.cakephp.org/t/how-to-use-find-threaded/9414/3 "2021-06-05T16:11:41Z")

</div>

i have modified my Table Structures to

```auto
CREATE TABLE `categories` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
    `name` varchar(255) DEFAULT NULL,
    `parent_id` INTEGER(10) DEFAULT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `categories` (`id`, `name`, `parent_id`) VALUES (NULL, 'Category 1', NULL);
INSERT INTO `categories` (`id`, `name`, `parent_id`) VALUES (NULL, 'Category 2', NULL);

```

```auto
CREATE TABLE `subcategories` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
    `name` varchar(255) DEFAULT NULL,
    `parent_id` INTEGER(10) DEFAULT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `subcategories` (`id`, `name`, `parent_id`) VALUES (NULL, 'Subcategory 1', 1);
INSERT INTO `subcategories` (`id`, `name`, `parent_id`) VALUES (NULL, 'Subcategory 1', 1);
INSERT INTO `subcategories` (`id`, `name`, `parent_id`) VALUES (NULL, 'Subcategory 1', 1);
INSERT INTO `subcategories` (`id`, `name`, `parent_id`) VALUES (NULL, 'Subcategory 1', 2);
INSERT INTO `subcategories` (`id`, `name`, `parent_id`) VALUES (NULL, 'Subcategory 1', 2);

```

CategoriesTable - Association

```auto
$this->hasMany('Subcategories', [
     'foreignKey' => 'parent_id'
]);

```

SubcategoriesTable - Association

```auto
$this->belongsTo('Categories');

```

At Controller i can call

```auto
TableRegistry::getTableLocator()
               ->get('Categories')
               ->find('threaded')
               ->contain(['Subcategories'])
               ->toArray();

```

and i get “Categories” and it’s related “Subcategories”.  
But the Subcategories will stay within “subcategories” node not with in “ **children** ” node

I need to store Subcategories in an extra Table as it is used on other Places in the App

So how to get results into “children” node or does “threaded” not work with associated Tables as @Zuluru mentioned

---

<div class="post-metadata">

**Author:** ![Zuluru](https://yyz1.discourse-cdn.com/flex029/user_avatar/discourse.cakephp.org/zuluru/32/1230_2.png) [@Zuluru](https://discourse.cakephp.org/u/Zuluru)\
**Post date:** [June 5, 2021, 7:20pm UTC](https://discourse.cakephp.org/t/how-to-use-find-threaded/9414/4 "2021-06-05T19:20:27Z")

</div>

Categories hasMany Subcategories is a perfectly fine structure. Your original database setup was all fine for working with that. The only changes you needed to make were the change to the find call that I mentioned, eliminating `threaded` and using `contain` instead, and I also now see that the association from Categories to Subcategories should have been `hasMany` there instead of `belongsTo` (though `belongsTo` is right for the association from Subcategories to Categories).

If you insist on the list of subcategories that gets loaded into the category `children` instead of the default `subcategories`, you can use the `propertyName` parameter when adding the association.

Putting it all together:

```auto
CREATE TABLE `categories` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
    `name` varchar(255) DEFAULT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE `subcategories` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
    `name` varchar(255) DEFAULT NULL,
    `category_id` INT UNSIGNED NULL DEFAULT NULL
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

class CategoriesTable extends Table
{
    public function initialize(array $config)
    {
        $this->hasMany('Subcategories', [
            'foreignKey' => 'category_id',
            'propertyName' => 'children', // Though I recommend against this and just using the default
        ]);
    }
   ...
}

class SubcategoriesTable extends Table
{
    public function initialize(array $config)
    {
        $this->belongsTo('Categories');
    }
    ...
}

TableRegistry::getTableLocator()->get('Categories')->find()->contain(['Subcategories'])->toArray();

```

---

<div class="post-metadata">

**Author:** ![magic77](https://avatars.discourse-cdn.com/v4/letter/m/ee59a6/32.png) [@magic77](https://discourse.cakephp.org/u/magic77)\
**Post date:** [June 5, 2021, 7:39pm UTC](https://discourse.cakephp.org/t/how-to-use-find-threaded/9414/5 "2021-06-05T19:39:09Z")

</div>

@Zuluru thanks for your feedback. I will stay with the Solution using find without threaded and not overriding the “propertyName”. Thanks for this advice!  
As it is a very simple nesting in my case.