$cities=City::find(['country_id'=>2]);
$cities=City::find(['conditions'=>['country_id'=>2],'order'=>'city_id desc']);
$cities=City::find([['country_id'=>2],'order'=>'city_id desc']);
$cities=City::find(['conditions'=>'country_id =:country_id','bind'=>['country_id'=>2]]);
public static function find($parameters = null, $cacheOptions = null);