Defining relations between different objects in our application, for instance, a state have many cities, and belongs to a country , is termed as associations. Association establish a way to represent the database table relationship inside Cakephp. It helps in managing these associations easily.

Association types in Cakephp:

1. One to one - hasOne
2. One to many - has Many
3. Many to one - belongsTo
4. Many to many - hasAndBelongsToMany

Create Models for Country, State and City and paste the following code accordingly.

class Country extends Model {
	public $hasMany = array('State');
}

class State extends Model {
	public $belongsTo = array(
			'Country'
	);
	public $hasMany = array(
			'City'
	);	
}

class City extends Model {
	public $belongsTo = array(
			'State'
	);	
}

Next, create view and paste the follwing code:

code to fetch list of cities on the basis of state id:

<?php
	
	echo $this->Form->input('Cities', array(
                    'options' => $city,
                    'empty' => '-- Select cities --',
                    "placeholder" => "-- Select cities --",
					'id' => 'show_cities',
					'div'=>false,
					'label'=>false,
                    "name" => "data[User][city_id]"
                ));
?>

code to fetch list of states on the basis of country id:

<?php
	echo $this->Form->input('States', array(
                    'options' => $state,
                    'empty' => '-- Select State --',
                    "placeholder" => "-- Select State --",
					'onchange' => 'getstates();',
					'div'=>false,
					'label'=>false,
					'id'=>'states',
                    "name" => "data[User][state_id]"
                ));

?>

Create Controller:

code to call the cities function:

public function getCities() { 

		$this->layout = null;

		if ($this->request->is('post'))
		{
			extract($this->request->data);

			$cities = $this->City->find('list', array('fields' => array('id','name'),'conditions' => array('City.state_id' => $state)));
			//print_r($cities);die;
			$this->set('city', $cities);
			$this->render('/Elements/getCities');
			

		}		
	}

code to call the states function:

public function getStates() {

		$this->layout = null;

		if ($this->request->is('post'))
		{
			extract($this->request->data);
			$states = $this->State->find('list', array('fields' => array('id','State.name'),'conditions' => array('State.country_id' => $country)));
			
			$this->set('state', $states);
			$this->render('/Elements/getData');

		}		
	}