Get rendered SQL from CodeIgniter active record script

I am a little confused in wriiting a SQL query for joining multiple tables.

I have perfectly written the query in CodeIgniter as follows:

$this->db->select('*');
$this->db->from('subscription_payment'); 
$this->db->join('user', 'user.user_id = subscription_payment.user_id');
$this->db->join('subscription', 'subscription.subscription_id = 
subscription_payment.subscription_id');
$this->db->where('subscription_payment.subscription_payment_id',$sid);
$query = $this->db->get(); 
$result= $query->result_array();

Help me to convert this to a plain SQL query.

SELECT *
FROM subscription_payment
JOIN user ON user.user_id = subscription_payment.user_id
JOIN subscription ON subscription.subscription_id = subscription_payment.subscription_id
WHERE subscription_payment.subscription_payment_id = $sid 
;