edit form is not updating its add as new row

[mdvignesh]

public function editContact( $c_id = null ) {
		//echo $c_id;
		
		if( !$c_id ) {
			throw new NotFoundException( __( 'Invalid Post' ) );
		}
		
		$contact = $this->Contact->findBycId( $c_id );
		if( !$contact ) {
			throw new NotFoundException( __( 'Invalid Post' ) );
		}
		//$id = $c_id;
		if( $this->request->is( array( 'post', 'put' ) ) ) {
			$this->Contact->cid = $c_id;
			
			if( $this->Contact->save( $this->request->data ) ) {
				$this->Session->setFlash( __( 'Data Updated' ) );
				return $this->redirect( array( 'action' => 'index' ) );
			}
			$this->Session->setFlash( __( 'Unable To update Data!' ) );
		}
		
		if( !$this->request->data ) {
			$this->request->data = $contact;
		}
	}

edit action in my controller

 

in my contacts table I'm having 'c_id' instead of 'id'

 

I also add this public $primaryKey = 'c_id'  in Contact.php model file

But still I get

column not found unknown column contact.id in where clause