MySQL пример сложного запроса с подзапросом, GROUP BY, ORDER_BY, LEFT JOIN, LIMIT, SUM IF - суммы с условием

Вот такой пример:

SELECT * FROM ( # начало подзапроса
	SELECT us.user_id, us.seller_profile, us.customer_profile, us.seller_about, us.customer_about, 
			SUM(if(ur.etype = 1, 1, 0)) AS seller_recalls_count, 
			SUM(if(ur.etype = 3 OR ur.exch_type = 4, 1, 0)) AS customer_recalls_count  
		FROM user_settings us LEFT JOIN user_recall ur ON us.user_id = ur.recipient_id 
			WHERE (noindex = 0)  GROUP BY us.user_id ORDER BY user_id LIMIT 5000 , 500  
	) as sub_table #конец подзапроса
WHERE (customer_recalls_count > 0) 
      OR (seller_recalls_count > 0) 
		OR  (seller_about IS NOT NULL AND seller_about <> '') 
		OR (customer_about IS NOT NULL AND customer_about <> '');