在自链接模型中，删除父节点时删除子节点

I want to delete all the child node(child categories) while deleting the parent category(using 'dependent'=> true). Here is the brief explanation I am working with a Self-linking model. Let's consider I have 2 tables

1. Categories
2. Products

where the category is multilevel. so that I have a column in the Categories table named as "parent_category_id". I have self-linked my model as bellow,

$this->belongsTo('FileCategories', [
        'foreignKey' => 'parent_category_id',
        'className' => 'FileCategories',
        'joinType' => 'INNER',
        'dependent'=> true
    ]);

Dependent "true" is not working in this cenerio, so Is I am doing something wrong or there is another method to do this.

You should also add hasMany relationship as below.

$this->hasMany('Parent', [
    'foreignKey' => 'parent_category_id',
    'className' => 'FileCategories',
    'joinType' => 'INNER',
    'dependent'=> true
]);

If it does not work, you can try this option ('cascadeCallbacks' => true).

$this->hasMany('Parent', [
    'foreignKey' => 'parent_category_id',
    'className' => 'FileCategories',
    'joinType' => 'INNER',
    'dependent'=> true,
    'cascadeCallbacks' => true
]);