Cakephp 3.0 delete not working for same table association? - php

Question

I have a category table with parent category Id in the same tables. And add the association to join the same table for classified child category. Below are my table structure, table association code and delete function.But delete not working :(.
Table Structure :-
CREATE TABLE IF NOT EXISTS `category` (
`Cat_Id` int(11) NOT NULL,
`Cat_Code` varchar(255) NOT NULL,
`Cat_Desc` text NOT NULL,
`CreatedBy` varchar(255) NOT NULL,
`ParentId` int(11) NOT NULL DEFAULT '0',
`GstPercentage` double NOT NULL DEFAULT '0',
`CreatedDate` datetime NOT NULL,
`UpdateDate` datetime NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
--
-- Indexes for dumped tables
--
--
-- Indexes for table `category`
--
ALTER TABLE `category`
ADD PRIMARY KEY (`Cat_Id`),
ADD UNIQUE KEY `Cat_id` (`Cat_Id`);
--
-- AUTO_INCREMENT for dumped tables
--
--
-- AUTO_INCREMENT for table `category`
--
ALTER TABLE `category`
MODIFY `Cat_Id` int(11) NOT NULL AUTO_INCREMENT;
Model Association :-
public function initialize(array $config)
{
parent::initialize($config);
$this->table('category');
$this->displayField('Cat_Id');
$this->primaryKey('Cat_Id');
// association for the same table join
$this->belongsToMany('Parents', [
'className' => 'Category',
'joinTable' => 'category',
'foreignKey' => 'Cat_Id',
'targetForeignKey' => 'ParentId',
]);
// used to associate the table with user table (join)
$this->belongsTo('Users', [
'className' => 'Users',
'foreignKey' => 'CreatedBy',
'propertyName' => 'user'
]);
}
Delete Function :-
public function delete($id = null)
{
$this->request->allowMethod(['post', 'delete']);
$category = $this->Category->get(base64_decode($id));
if ($this->Category->delete($category)) {
$this->Flash->success(__('The category has been deleted.'));
} else {
$this->Flash->error(__('The category could not be deleted. Please, try again.'));
}
return $this->redirect(['action' => 'index']);
}