нужна помощь для создания запроса базы данных codeigniter

Question

Я хочу сделать это с помощью функции codeigniter query_builder. Не получая Идею, пожалуйста, помогите.

$this->db->query("SELECT city as popularcity FROM(SELECT city,count(city) as 
countcity FROM ads LIMIT 0, 6) as t ORDER BY MAX(countcity)"); 

Answer 1

$this->db->query("SELECT city as popularcity, countcity 
FROM 
(SELECT city, count(city) as countcity FROM ads GROUP BY city) as t 
ORDER BY countcity DESC LIMIT 0, 6"); 

Answer 2

Try ниже код,

$this->db->select("city as popularcity, countcity"); 
$this->db->from("(SELECT city, count(city) as countcity FROM ads GROUP BY city) as t"); 
$this->db->order_by("countcity DESC"); 
$this->db->limit(0,6);